To analyze the relationship of cocoa intake to central and peripheral blood pressure, arterial stiffness, and carotid intima-media thickness in subjects with some cardiovascular risk factor.Design: A cross-sectional study of 351 subjects . Measurements: Intake of cocoa and other foods using a food frequency questionnaire, central and peripheral (ambulatory and office) blood pressure, central and peripheral augmentation index, pulse wave velocity, ambulatory arterial stiffness index, carotid intima-media thickness, and ankle-brachial index.p < 0.05). In a multivariate analysis, these differences disappeared after adjusting for age, gender, the presence of diabetes, systolic blood pressure and antihypertensive and lipid-lowering drug use. All other arterial stiffness measures  showed no differences between the different consumption groups.Results: Higher pulse wave velocity and greater cardiovascular risk were found in non-cocoa consumers as compared to high consumers (In subjects with some cardiovascular risk factors, cocoa consumption does not imply improvement in the arterial stiffness values.NCT01325064.Clinical Trials.gov Identifier:  Cocoa intake is related to a lower cardiovascular risk ,2. AlthoThe benefits of cocoa could be explained by an improved endothelial function and a beneficial effect on blood pressure , particuThe purpose of this study was to analyze the relationship of cocoa intake to central and peripheral blood pressure, arterial stiffness, and carotid intima-media thickness in subjects with some cardiovascular risk factor.A cross-sectional study conducted on 351 subjects in a primary care setting. Participants were recruited at primary care offices during 2010. Sample size was estimated to detect a minimum difference of 1 m/sec in pulse wave velocity (PWV) between two of the three groups in which sample was divided based on cocoa intake. Assuming an alpha risk of 0.05 and a beta risk of 0.2 in a two-sided test and a standard deviation of 2.1, 93 subjects per group were required, 279 in total. The study adhered to the principles of the Declaration of Helsinki , and wasInformation about the frequency of cocoa intake and all other foods was collected using the food frequency questionnaire of the University of Navarre, validated for Spain . This quProcedures for measuring office and ambulatory blood pressure, ankle-brachial index (ABI), body mass index, and abdominal waist circumference have been reported in a prior publication .Central blood pressure (CBP) and central and peripheral augmentation index  were estimated using the SphygmoCor System . With the patient sitting and the arm resting on a rigid surface, pulse wave in radial artery was tested and used to estimate the aortic pulse wave using a mathematic transformation. Inter-observer reliability was assessed before the start of the study using an intraclass correlation of 0.974 (95% CI: 0.936-0.989) in repeated measures in 22 subjects and with Bland-Altman analysis, where inter-observer agreement limits were 0.454 (95% CI: -9.876-10.785). Using the SphygmoCor System (Vx pulse wave velocity), PWV was measured with the patient in the supine position, estimating the delay in pulse wave at carotid and femoral level as compared to the electrocardiogram wave. Ambulatory arterial stiffness index (AASI) is defined as 1 minus the regression slope of 24-hour diastolic on systolic blood pressure .Carotid ultrasonography to assess intima-media thickness of the common carotid artery (C-IMT) was performed by two investigators specifically trained for that purpose. A Sonosite Micromax ultrasound device  paired with a 5-10 MHz multifrequency high-resolution linear transducer with Sonocal software was used for performing automatic measurements of IMT, in order to optimize reproducibility. Reliability of this measurement was evaluated before study start using intraclass correlation coefficient, which showed values of 0.974 (95% CI: 0.935-0.990) for intra-observer agreement on repeated measurements in 20 subjects, and 0.897 (95% CI: 0.740-0.959) for inter-observer agreement. Six measurements were taken on each carotid artery, using average values (average IMT) and maximum values (maximum IMT) calculated by the software automatically. Measurements were taken following the recommendations of the Manheim Carotid Intima-Media Thickness Consensus . CardiovContinuous variables are expressed as the mean ± standard deviation, and qualitative variables as frequency distributions. Association between qualitative variables was assessed using a Chi-square test, differences in means between groups with an ANOVA test, and a Scheffé test was used as a post hoc test with an alpha value < 0.05. We used a multivariate analysis based on the ANCOVA method , to compare the arterial stiffness variables between different cocoa-intake groups using as adjustment variables age, gender, systolic blood pressure, diabetes and the presence of medical treatment (antihypertensive and lipid-lowering drugs). SPSS/PC + version 18.0 statistical software was used .p < 0.05).Sample consisted of 351 subjects . Mean cocoa consumption of the global sample was 4.30 ± 9.08 g/day, with an intake among those who consumed some cocoa of 7.74 ± 11.04 g/day, and a median value of 2 g/day. Table The proportion of patients treated with drugs was greater among the non-consumers of cocoa than in the high consumption group, referred to both the antihypertensive agents (53.80% vs 37.80%) and the lipid-lowering drugs (37.10% vs 15.70%). A higher proportion of males (30.59%) as compared to females (16.67%) reported high cocoa consumption.p = 0.039). However, in the multivariate analysis, on adjusting for age, gender, the presence of diabetes, systolic blood pressure and antihypertensive and lipid-lowering drug use, this difference disappeared. The power of the contrast was 81% for detecting differences in PWV between high consumers and non-consumers, and 42% between high consumers and low consumers. All other arterial stiffness measures showed no differences between the different consumption groups  and the high consumption group (8.47 m/sec) . Member of the cardiovascular research group  Carlos III Institute of Health of the Spanish Ministry of Health, SACYL. MAG and LG are MD, associate professors at the Department of Medicine, University of Salamanca and members of the cardiovascular research group  Carlos III Institute of Health of the Spanish Ministry of Health, SACYL. CA (nurse) and ER (MD) are members of the cardiovascular research group  Carlos III Institute of Health of the Spanish Ministry of Health, SACYL. MCP (PhD) is an Assistant professor at the Statistics Department, University of Salamanca.


Obstructive sleep apnea (OSA) and hypertension are well-known cardiovascular risk factors. Their control could reduce the burden of heart disease across populations. Several drugs are used to control hypertension, but the only consistently effective treatment of OSA is continuous positive airway pressure. The identification of a drug capable of improving OSA and hypertension simultaneously would provide a novel approach in the treatment of both diseases.This is a randomized double-blind clinical trial, comparing the use of chlorthalidone with amiloride versus amlodipine as a first drug option in patients older than 40 years of age with stage I hypertension (140 to 159/90 to 99 mmHg) and moderate OSA (15 to 30 apneas/hour of sleep). The primary outcomes are the variation of the number of apneas per hour and blood pressure measured by ambulatory blood pressure monitoring. The secondary outcomes are adverse events, somnolence scale (Epworth), ventilatory parameters and C reactive protein levels. The follow-up will last 8 weeks. There will be 29 participants per group. The project has been approved by the ethics committee of our institution.The role of fluid retention in OSA has been known for several decades. The use of diuretics are well established in treating hypertension but have never been appropriately tested for sleep apnea. As well as testing the efficacy of these drugs, this study will help to understand the mechanisms that link hypertension and sleep apnea and their treatment.NCT01896661ClinicalTrials.gov:  Obstructive sleep apnea (OSA) is a well-known cardiovascular risk factor and a major cause of secondary hypertension ,2. AboutThe association between OSA and hypertension has been disregarded by clinicians and even by researchers of hypertension . The higThe standard treatment for OSA is continuous positive airway pressure (CPAP) and 46 clinical trials show the benefits . It has A Cochrane review, which identified 26 clinical trials of 21 drugs totaling 394 patients, failed to identify any pharmacological treatment with consistent efficacy. Some drugs, like fluticasone, mirtazapine, physostigmine and nasal lubricants, seem to reduce the number of apneas, but the trials were small and had methodological limitations, precluding the use of these drugs in clinical practice . It has An extravascular fluid shift has been implicated in the physiopathology of OSA. During the night, a shift of fluids from the legs causes an increase in neck circumference, peripharyngeal pressure and upper airway collapsibility -19. AlmoR2 = 0.56) [Patients with controlled hypertension underwent a reduction of 175 mL in leg volume and an increase of 1.0 cm in neck circumference after sleeping, in comparison with a leg volume reduction of 346.7 mL and an increase in the neck circumference of 1.5 cm in patients with resistant hypertension . The leg = 0.56) . CPAP re = 0.56) .Sympathetic renal ablation with radio-frequency waves reduced blood pressure by 33/11 mmHg in 6 months . It alsoIn the ALLHAT trial, chlorthalidone, lisinopril and amlodipine had comparable efficacy in the prevention of coronary heart disease . The diuThe main adverse event for chlorthalidone is hypokalemia, which blunted the efficacy of the treatment in the SHEP trial  and incrAmlodipine was more effective than valsartan, an angiotensin receptor blocker, in the prevention of myocardial infarction and stroke in the VALUE trial . In the Overall the evidence shows that chlorthalidone and amlodipine are the most effective drugs for the initial treatment of hypertension. Their use in OSA has not been appropriately tested to date. Thus, a trial testing the efficacy of these drugs to control both blood pressure and sleep apnea is warranted. Such a trial could contribute to our understanding of the relation between hypertension, fluid levels, hypoxia and OSA.OSA has been associated with fluid retention, which accumulates in the pharynx facilitating its collapse, generating intermittent hypoxia and increasing sympathetic activity and blood pressure. CPAP alleviates apnea, which reduces sympathetic activity, reducing blood pressure and increasing salt and water excretion. Sympathetic renal ablation promotes salt and water excretion, reducing systemic sympathetic activity and total body water (including the pharynx), thus alleviating apnea. Diuretics could be a new way to abort this vicious cycle by promoting the direct excretion of salt and water.Is chlorthalidone with amiloride effective in the treatment of OSA in comparison to amlodipine in patients with OSA and hypertension?This is a randomized double-blind clinical trial, controlled by an active treatment.Eligible participants are patients older than 40 years of age with stage I hypertension (140 to 159/90 to 99 mmHg) and moderate OSA (15 to 30 apneas/hour of sleep).Patients are excluded if they have a low life expectancy, other indications for the use of diuretics or calcium channel blockers, intolerance or contraindications to the study drugs, cardiovascular disease , secondary hypertension or participated in another clinical trial in the previous 6 months or if they are pregnant or use more than one drug for hypertension.Randomization will be done using a list generated by validated software , with a block size of four.The interventions are chlorthalidone plus amiloride 25 mg and 5 mg daily, respectively, versus amlodipine 10 mg daily, taken in the morning.1. Number of apneas/hour (apnea-hypopnea index)2. Blood pressure1. Adverse events2. Somnolence scale (Epworth)3. Respiratory parameters4. C reactive proteinThere will be outpatient clinical visits for evaluation at enrollment and week 8 of treatment. Figure The number of apneas/hour will be measured at the baseline and follow-up by type III portable polysomnography , which was validated by us . AverageSleepiness will be measured using the Epworth somnolence scale at the baseline and follow-up. It records the likelihood that someone will fall sleep during eight daily activities .Adverse events will be investigated using open questions and a semi-structured questionnaire, with questions on general symptoms and the presumed adverse effects of the drugs used in the trial. Standard laboratory tests will be used to identify adverse events, such as hypokalemia and elevated glucose levels. C-reactive protein levels will be determined as well.Patients taking an antihypertensive drug will need to stop it for 2 weeks prior to the study to be confirmed for eligibility, to allow time for most of the effects of the blood pressure drug to vanish .Adherence will be check by counting pills.P alpha of 5%, 26 patients will be required per group. The sample will be increased by 10% to account for possible losses in follow-up, so that 58 patients need to be randomized.For a mean of 20 apneas/hour at the baseline and a reduction of 7 apneas/hour, with a standard deviation of 9 apneas/hour, power of 80% and t tests for continuous variables. Confounding will be controlled with logistic regression and multiple linear regression models.Differences between variables for the groups will be analyzed with chi-squared tests for categorical and Student’s The project and the informed consent form were approved by the ethics committee of the Hospital de Clínicas de Porto Alegre, which is accredited by the Office of Human Research Protections as an Institutional Review Board. All participants will be asked to sign the informed consent form prior to participation in the study.The trial is currently recruiting patients.CPAP: Continuous positive airway pressure; OSA: Obstructive sleep apnea.The authors declare that they have no competing interests.FTC conceived the study, revised the background, prepared the data collection plan and prepared the draft of the manuscript. DM participated in the revision of the background, participated in preparing the data collection plan and contributed to drafting the manuscript. SCF participated in preparing the data collection plan and contributed to drafting the manuscript. MG participated in the revision of the background, and revised the draft of the manuscript. LBM participated in preparing the data collection plan and revised the draft of the manuscript. FDF conceived the study, participated in preparing the data collection plan and prepared the final version of the manuscript. All authors read and approved the final version of the manuscript.


To determine the association between left ventricular hypertrophy and insulin resistance in Gambians.Cross-sectional study.Outpatient clinics of Royal Victoria Teaching Hospital and Medical Research Council Laboratories in Banjul.Three hundred and sixteen consecutive patients were enrolled from outpatient clinics. The data of 275 participants  were included in the analysis with a mean (± standard deviation) age of 53.7 (±11.9) years.A questionnaire was filled and anthropometric measurements were taken. 2-D guided M-mode echocardiography, standard 12-1ead electrocardiogram, fasting insulin and the oral glucose tolerance test were performed.2 in males and 110 g/m2 in females as the cut-off for left ventricular hypertrophy. Using the fasting insulin and fasting glucose levels, the insulin resistance was estimated by the homeostatic model assessment formula. Logistic regression analysis was used to determine the association between left ventricular hypertrophy and insulin resistance.The Penn formula was used to determine the left ventricular mass index, 125 g/mThe mean Penn left ventricular mass index was 119.5 (±54.3) and the prevalence of Penn left ventricular mass index left ventricular hypertrophy was 41%. The mean fasting glucose was 5.6 (±2.5) mmol/l, fasting insulin was 6.39 (±5.49) μU/ml and insulin resistance was 1.58 (±1.45). There was no association between Penn left ventricular mass index left ventricular hypertrophy and log of insulin resistance in univariate  and multivariate logistic regression  analysis.No association was found in this study between left ventricular hypertrophy and insulin resistance in Gambians and this does not support the suggestion that insulin is an independent determinant of left ventricular hypertrophy in hypertensives. Left ventricular hypertrophy (LVH) and insulin resistance (IR) are both strong adverse factors for cardiovascular disease. The co-existence of LVH and IR is a clinical finding, which must be taken seriously, even in the absence of blood pressure levels above the usual limits for initiating drug therapy because it is a predictor of adverse risk for mortality and morbidity.The association of hypertension and IR has been studied extensively as part of the metabolic syndrome In a study of 40, otherwise healthy, non-diabetic, normotensive obese subjects Sasson et al demonstrated that IR was strongly associated with LVH and that this association was independent of blood pressure and body mass index (BMI) IR was found to have no influence on left ventricular mass index in a study of 29 non-obese hypertensive patients The prevalence and relevance LVH and IR in Gambians are unknown. The aim and objective of this study are to determine the association between LVH and IR in Gambians.The study was approved by The Gambia Government/MRC Ethical Committee. All the participants signed or thumb printed an informed consent form after careful consideration and explanation.This was a cross sectional study conducted at the Royal Victoria Teaching Hospital, Banjul and the Medical Research Council (MRC) Laboratories, Fajara, The Gambia. Patients with hypertension attending the Royal Victoria Teaching Hospital hypertension clinic were recruited consecutively. The non-hypertensive patients were recruited from the Gate Clinic of the MRC Laboratories, Fajara. These were patients who reported with minor infections and were not diabetic and had no cardiovascular disease. The recruitment of participants was conducted from January to May 2000.2), systemic or metabolic diseases, severe inter-current illnesses; known diabetes mellitus, cardiovascular disease (excluding hypertension) or labile hypertension (labile hypertension is when the blood pressure is sometimes above or sometimes below 140/90 mmHg), Patients with morbid obesity  on electric scales , with subjects wearing light clothes and without footwear. The height was measured to the nearest 0.5 cm without footwear or head gear using standardised stadiometers. Hip and waist circumferences were measured using a plastic tape measure and recorded to the nearest 0.5 cm. The blood pressure was measured on the left arm using digital blood pressure machines  A 3.5 MHz transducer on Hitachi EUB – 405 ultrasound scanner was used in performing 2-dimensional M-mode guided echocardiography on participants. The subjects were studied most commonly in the left lateral or partial left lateral position. The posterior left ventricular wall thickness was measured from the endocardial echo to the edge of the acoustic epicardial echo while the inter-ventricular septum was measured between its endocardial echoes The left ventricular end-diastolic diameter (LVEDD) was measured from the leading edge of the anterior endocardium to the leading edge of the posterior wall endocardium at end-diastole. The left ventricular end-systolic diameter (LVESD) was measured from inner edge of the anterior endocardium to the inner edge of the posterior wall endocardium of the left ventricle at end-systole. Polaroid paper were used to record all the distances, time and heart rate during the procedure.An OGTT was carried out on participants during which, insulin levels were measured. The OGTT was performed using 75 g anhydrous glucose in 300–350 ml of water. A Haemocue analyser  was used to immediately determine glucose level on fasting, 30 min and 120 min samples. The detailed results of the OGTT are presented in another article which is in print. However the information was used in classifying participants as DM in this study. Insulin level of a fasting sample was measured in the MRC NCD Laboratory with the Abbott IMx Immunoassay Analyser, which utilises a Micro-particle Enzyme Immunoassay (MEIA).Using the fasting insulin and fasting glucose levels, the IR was estimated by the homeostatic model assessment (HOMA) formula.The following definitions were adopted for this study.1. Hypertension is systolic blood pressure≥140 and/or diastolic blood pressure≥90.mmHg in subjects who are not taking antihypertensive medication.2.2. Overall Obesity is Body Mass Index (BMI)≥30 kg/m3. Central Obesity or High Waist Hip Ratio (WHR) is WHR>0.9 for males and>0.8 for females.4. Diabetes. World Health Organisation Study Group on Diabetes Mellitus (1998). Fasting venous blood glucose>7.0 mmol/L and or 2 h post glucose capillary whole blood≥11.1 mmol/L 5. Insulin Resistance (IR)  =  6. Echocardiographic LVH CriteriaPenn convention/Formula: Left ventricular mass (PLVM) (g) =  1.04 {(IVSTD + LVPWTD + LVEDD) 3 – LVEDD3} – 13.62)Penn left ventricular mass indexed to body surface area (PLVMI) (g/m2)  =  Body Surface Area (mPenn left ventricular mass index (PLVMI)  =  PLVM/BSAPenn left ventricular echocardiographic LVH (PLVMILVH) defined by:2 in males and PLVMI>110 g/m2 in females PLVMI>125 g/m7. Smoking was defined as “ever smoked” as compared to non-smoking which was defined as “never smoked”.The data was analysed using Stata version 8.0. The mean and standard deviation (sd) were used for continuous variables, and were compared using standard t-test. Discrete variables were analysed using Pearson chi squared test. The results of OGTT and IR were not normally distributed so a logarithmic transformation was done and this was used in all further analysis. Univariate and multivariate linear regression was used to analyse the association between log of IR and variables such as sex, smoking, hypertension, DM, BMI≥30, high WHR, antihypertensive treatment, age, BMI, WHR, SBP, DBP and fasting glucose. The association between PLVMILVH and log of IR was analysed using univariate and multivariate logistic regression controlling for various confounding variables. P-values of less than 0.050 were taken as statistically significant.Two hundred and eight consecutive patients  with hypertension on treatment and 108 non-hypertensive patients  were enrolled from outpatient clinics for our initial study The mean (± sd) age of participants was 53.7 (±11.9) years and the age range was 27–85  and 2. TThere were 166 (60.4%) participants  on antihypertensive drugs and all of them were hypertension patients. However 13 hypertensives were not on drug treatment and none of the nonhypertensives were on antihypertensive treatment. There were 28 participants on a combination of 3 drugs, 94 on a 2 drug combination and 44 on monotherapy. The majority (137 participants) were on bendrofluazide and this was followed by methyldopa, propranolol, nifedipine, hydralazine, hydrochlorothiazide and atenolol in that order. There was a patient each on amlodipine and captopril.The echocardiographic characteristics of participants were all significantly higher in the males than the females except LVEDD which was similar in both sexes . The meaThere were no statistically significant sex differences in the biochemical characteristics of the participants . The meaIn univariate logistic regression analysis with PLVMILVH as the outcome variable there were significant association between PLVMILVH and sex (p = 0.052), hypertension (p = 0.008), antihypertension treatment (p = 0.028), age (p = 0.002), WHR (p = 0.021) and SBP (p = 0.001). HoweverWith log of IR as the outcome variable there were significant association between log of IR and DM (p<0.001), high WHR (p = 0.038), WHR (p = 0.006), BMI (p<0.001) and log of fasting glucose (p<0.001) . There wMore importantly there was no association between PLVMILVH and log of IR in univariate logistic regression analysis  .From the results of the univariate analysis WHR was the only variable which was associated with both PLVMILVH and log of IR. Therefore in a multiple logistic regression analysis we modeled with PLVMILVH as the outcome variable and WHR and log of IR as the explanatory variables. There was no significant association between PLVMILVH and log of IR . WHR was however still associated with both PLVMILVH and log of IR . There was still no significant association between PLVMILVH and log of IR in other models with PLVMILVH as the outcome variable and controlling for different variables. In further multivariate analysis with PLVMILVH as the outcome variable and controlling for various variables which were associated PLVMILVH in univariate analysis, the following variables were found to be associated with PLVMILVH, age  and SBP . When multiple regression analysis was done with log of IR as the outcome variable and the variable which were associated with log of IR in univariate analysis were included, BMI  and log of fasting glucose  were found to be the variables which were significantly associated with log of IR.Further subgroup univariate logistic regression analysis with PLVMILVH as the outcome variable and log of IR as the explanatory variables was carried out for the various categorical variables. There was no association between PLVMILVH and log of IR in males, females, smokers, non-smokers, hypertensives, non-hypertensives, DM, non-DM, BMI ≥ 30, BMI < 30, high WHR and normal WHR .In this study the relationship between LVH and IR was investigated using fasting blood glucose, fasting insulin and the HOMA formula for estimating IR and PLVMI. There was no statistical significant association between PLVMILVH and IR in these participants in univariate and multivariate regression analysis after controlling for various variables. Also in subgroup analysis using univariate logistic regression analysis there was no significant association between these two variables. Therefore, IR may not play a role in the development of LVH in this population of Gambians.The most significant risk factors for LVH were the older the age of the subject and the higher the SBP rather than IR. On the other hand the significant risk factors for IR were high BMI and high fasting blood glucose. WHR which was a common significant variable to both LVH and IR was still significant in the multiple regression model but after adjusting for this variable there was still no significant association between LVH and IR.Several mechanisms have been proposed to explain why there should be a direct relationship between IR and LVH. To date the best indirect evidence is the fact that angiotensin II receptor blockers correct both IR and LVH Other direct and indirect mechanisms have been proposed for the contribution of IR in the development of LVH. These include the disordered and increased re-adsorption of sodium in the kidneys The association between LVH and IR from the published literature has been variable. There have been several studies reporting a positive relationship while there are not too few papers which have established that there is no relationship between LVH and IR. Significant associations between IR and LVH have been demonstrated in hypertensive patients as well as obese subjects et al demonstrated in 70 diabetic patients that there was no statistically significant correlation between LVH and HOMA derived IR et al study. IR and fasting insulin has also been shown not to be associated with LVH in healthy people, independent of obesity. This was in a cross-sectional relational study carried out in 153 healthy subjects, comprising 76 men and 77 women who were normotensive, had a normal oral glucose tolerance test, no cardiovascular disease and none were on any medication et al investigated the relationship between left ventricular mass index  and cardiovascular risk factors Other studies however have shown only weak association between LVH and IR This study is one of the few cardiovascular studies which have been undertaken in The Gambia. To date there has not been any published data on LVH nor IR from this small West African country. This is the major strength of this pioneering study. The finding of no association between LVH and IR therefore raises the question as to whether this is an observation peculiar to this community or part of the world. The main weakness of the study was the fact that it was a hospital based study which was fraught with various biases including selection and proximity biases. Another potential limitation of this study was the fact that the insulin levels were measured only in the fasting state but not after the glucose load was administered. Some studies have demonstrated a positive association between LVH and postload insulin levels There was no significant association between echocardiographic LVH and IR in this population of Gambians. Our findings do not support the suggestion that insulin is an independent determinant of LVH in hypertensives.


Background: During caesarean section spinal anesthesia may provoke maternal hypotension that we prevent by administration of phenylephrine and/or ephedrine. Phenylephrine is however reported to reduce the near infrared spectroscopy-determined frontal lobe oxygenation (ScO2) but whether that is the case for patients exposed to spinal anesthesia is not known.Objectives: To evaluate the impact of phenylephrine vs. ephedrine on ScO2during caesarean section with spinal anesthesia in a single center, open-label parallel-group study with balanced randomization of 24 women (1:1). Secondary aims were to compare the effect of the two drugs on maternal hemodynamics and fetal heart rate.Intervention: Ephedrine (0.8–3.3 mg/min) vs. phenylephrine infusion (0.02–0.07 mg/min).Results: For the duration of surgery, administration of ephedrine maintained ScO2  with a 10.7% difference in ScO2between groups (p = 0.0106). Also maternal heart rate was maintained with ephedrine (+3 ± 3 bpm) but decreased with phenylephrine (−11 ± 3 bpm); difference 14 bpm (p = 0.0053), but no significant difference in mean arterial pressure (p = 0.1904) or CO (p = 0.0683) was observed between groups. The two drugs also elicited an equal increase in fetal heart rate .Conclusion: In the choice between phenylephrine and ephedrine for maintenance of blood pressure during caesarean section with spinal anesthesia, ephedrine maintains frontal lobe oxygenation and maternal heart rate with a similar increase in fetal heart rate as elicited by phenylephrine.Trial registration: Clinical trials NCT 01509521 and EudraCT 2001 006103 35. Spinal anesthesia is used for caesarean section although it is commonly associated with hypotension. In addition to tilting patient to the left and providing i.v. fluids, we use ephedrine and/or phenylephrine to prevent or correct hypotension that could result in, e.g., dizziness, nausea, and vomiting and also hinder adequate perfusion of the child  decreases when hypotension is supported by phenylephrine  determined cerebral  oxygenation , written informed consent was obtained from healthy women undergoing elective caesarean section during spinal anesthesia after approval by the local ethics committee (SJ—271) and the Danish medicine agency . The Good Clinical Practice (GCP) unit at the University of Copenhagen monitored the trial conducted from April 2012 to July 2012 at Næstved Hospital. Eligible participants were older than 18 years in ASA group I or II, 160–180 cm and with a single pregnancy. Patients with either preeclampsia, non-singleton pregnancy, HELLP-syndrome , elevated serum bilirubin, or reported allergy to ephedrine or phenylephrine were excluded from the study.Upon arrival to the operating theater, the patient was provided with 500 mL isotonic saline, tilted 15° to the left and nasal supplementation of oxygen (2 L/min) was established. A cuff was applied to the third finger of the left hand and heart rate (HR), systolic (SBP), diastolic (DBP) and mean arterial (MAP) blood pressures were determined by Nexfin . Thus stroke volume (SV) was determined from the pressure curve using Modelflow  and 10 μg fentanyl spinal anesthesia was established using a 27 or 25 G pencil point needle at the L2–L3 or L3–L4 intervertebral space. Spinal anesthesia was administered in the right lateral position in 21 patients and in three patients spinal anesthesia was provided in a seated position. Surgery started when the sensory block included the T5 dermatome as indicated by the loss of sensation to application of cold to the skin.2 was monitored by NIRS . Optodes were placed on both sides of the forehead immediately below the hairline and secured with a headband that also served to seal ambient light. The NIRS-determined mean ScO2 is based on optodes that emit and detect near-infrared light at two wavelengths (730 and 810 nm) and ScO2 is calculated as the ratio between oxyhemoglobin and total hemoglobin. The signal detector closest to the light source (3 cm) is considered the “shallow detector” and used to attenuate influence from superficial tissue, while the detector 4 cm from the light source is considered to detect light from “deep tissue.” The distance between the source and detectors is considered sufficient for light to reach the brain  of 12 using sequentially numbered, opaque, sealed envelopes prepared by an individual not involved in the study. Dose equivalence between phenylephrine (0.1 mg/mL) and ephedrine (5 mg/mL) was chosen in according to previous trials and recommendations  and adjusted to maintain SBP. If SBP increased from baseline by 10–20%, the infusion was reduced to 10 mL/h and paused if SBP increased more than 20%. Conversely, if SBP decreased by 10–20%, the infusion was increased to 40 mL/h. A bolus of either 10 mg ephedrine or 0.2 mg phenylephrine was to be administered if SBP decreased by more than 20%, or if the patient complained of symptoms of hypotension . At delivery the infusion was reduced to 10 mL/h and terminated 5–15 min thereafter. Data collected included Apgar score, and umbilical arterial and venous blood gas variables from a double-clamped cord segment. Further, data pertaining to the duration of surgery, volume of saline administered and the vasopressor dosages used are mentioned.2 change from baseline, with baseline defined as rest prior to spinal anesthesia (time 0 min). The secondary outcomes variables  were also expressed as the change from baseline and all observations were continued until the end of surgery.The primary outcome is expressed as the percentage ScO2, assuming a common standard deviation of 7%, a sample size of n = 9 per group was required to obtain a power of a least 0.8 . To compensate for potential dropouts and missing data (25%) the sample size was increased to 12 participants per group. Data analyses were according to a pre-established plan using SAS software . Descriptive statistics and tests are reported in accordance with the “Enhancing the QUAlity and Transparency Of health Research” (EQUATOR) network: the CONSORT Statement  estimates of the variables . Comparing the values determined in the two groups, the difference in ScO2 was 10.7% , this was not the case with the administration of ephedrine (p = 0.4657).In patients allocated to administration of phenylephrine ScOp = 0.1904). Similar results were obtained for DBP and SBP (Table p = 0.0053) bpm. SV appeared to increase both with phenylephrine (9.7 ± 4.8 ml) and with ephedrine (4.4 ± 5.0 ml), but this difference was not significant: −5.3 ml . In the ephedrine group CO increased by 0.9 ± 0.4 l/min, while in the phenylephrine group CO was stable (−0.1 ± 0.4 l/min); 95% CI −0.08 to 2.02, p = 0.0683). There was a tendency for TPR to be lower in the ephedrine group compared with the phenylephrine group (−232 ± 42 vs. −129 ± 41) dyn s cm−5 (p = 0.0684).Phenylephrine −14 ± 3 mmHg) and ephedrine (−20 ± 3 mmHg) were equally effective in maintaining MAP ; for ephedrine +19 ± 3 vs. +18 ± 3 bpm for phenylephrine (Table p < 0.005) and phenylephrine (p < 0.005) increased fetal heart rate. All Apgar scores were = 8 one minute after delivery and increased to 10 after 5 min in both groups. There was a difference (p = 0.0223) in regard to the umbilical venous base excess: −1.0 (95% CI −0.86 to −0.14) mM and arterial umbilical lactate was higher in the ephedrine than in the phenylephrine group: 0.50 (95% CI 0.09–0.91) mM, p = 0.017, while no differences were observed in any of the other umbilical cord blood variables assessed ] and between intra-thecal injection and delivery  were similar for the ephedrine and the phenylephrine groups (Table p = 0.0515) and there was no difference in the blood loss (100 ml (95% CI of difference −275 to 475), p = 0.601).The time between intra-thecal injection and start of surgery [difference 0.0 (95% CI −2.8 to 2.8) min, ps Table . The amoThe ephedrine dose per minute was 1.7 mg (1.3–2) range 0.7–5.9 mg and of phenylephrine 1.38 mg (0.91–1.55) range 0.57–1.82 mg. No patient was treated with both phenylephrine and ephedrine.Further monitoring (not reported) included pulse oximetry, ECG, non-invasive blood pressure on the right arm after initiation of saline administration and continued until the patient was transferred to the postoperative observation unit .2) while ScO2 was reduced in patients allocated to administration of phenylephrine, a selective α-adrenergic receptor agonist. We considered that women going through caesarean section during spinal anesthesia might be hypovolemic because of compromised venous return and that phenylephrine therefore could support cardiac output and in turn cerebral oxygenation as expressed by ScO2. In contrast to our hypothesis, however, phenylephrine did not increase CO and maybe therefore reduced ScO2. In other word, with the established routine for maintaining the circulation during caesarean section during spinal anesthesia, CO in response to administration of phenylephrine indicated that the patients were maintained “normovolemic.” Furthermore, only ephedrine maintained HR and the two drugs elicited an equal almost 20 bpm increase in fetal heart rate.The present study confirmed that phenylephrine and ephedrine are equally effective in maintaining MAP in patients undergoing caesarean section with spinal anesthesia. The new finding is that in patients undergoing spinal anesthesia, the use of the ephedrine, capable of activating both α and β adrenergic receptors, preserves the near infrared-determined frontal lobe oxygenation  Continuous wave (CW), (2) Frequency-domain (FD), and (3) time domain technology (TD). An approximate 3–4% decrease in ScO2 and maternal heart rate when compared to ephedrine but the two drugs induced an equal increase in fetal heart rate.This study confirmed that infusion of phenylephrine and ephedrine are equally effective for sustaining blood pressure during elective caesarean section with spinal anesthesia. Phenylephrine, however, reduced ScOPeter Nissen, Niels H. Secher, Henning B. Nielsen, Kim Z. Rokamp, and Visti T. Foss conceived and designed the trial protocol. Visti T. Foss procured the project funding in cooperation with Department of Anaesthesia, Næstved Hospital, Denmark. Visti T. Foss and Kim Z. Rokamp contributed to clinical screening and recruitment of patients. Visti T. Fossand Kim Z. Rokamp handled the cooperation with the Good Clinical Practice (GCP) unit at the University of Copenhagen with VF as primary investigator and Kim Z. Rokamp as sponsor. Visti T. Foss and Robin Christensen did the statistical analyses. Visti T. Foss, Robin Christensen, Niels H. Secher and Kim Z. Rokamp drafted the manuscript, and Peter Nissen and Henning B. Nielsen contributed to the manuscript. All authors read and approved the final manuscript. Visti T. Foss and Kim Z. Rokamp accept full responsibility for this work and act as guarantors for the study.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


It was previously reported that the brachial-ankle pulse wave velocity (baPWV) is elevated in preeclamptic women. However, baPWV is strongly affected by blood pressure. Recently, a new index of vascular stiffness, the cardioankle vascular index (CAVI), was developed. CAVI is thought to be an index independent of blood pressure. We assessed CAVI in normotensive and hypertensive pregnant women. We studied a total of 109 Japanese women consisting of 23 nonpregnant healthy women (group A), 45 normotensive pregnant women (group B), 28 pregnant women complicated with established preeclampsia (group C), and 13 pregnant women with chronic hypertension (group D). The subject remained supine while the blood pressure, baPWV, and CAVI were recorded. No significant difference in baPWV was present between groups C and D, but the difference in CAVI was significantly high in group D. We believe that we can distinguish the vessel structural change between chronic hypertension and preeclampsia through simultaneous baPWV and CAVI measurements. For early detection of arteriosclerotic disease, several parameters for assessing vascular nature have been used. The pulse wave velocity (PWV) is one of these parameters and has been widely used mainly in the field of internal medicine, especially in the prediction of cardiovascular events . The oriβ [Recently, a new index of vascular stiffness, the cardio ankle vascular index (CAVI), was developed. Considered to be an index independent of blood pressure, CAVI is a parameter of adjusted PWV for blood pressure, based on a stiffness parameter β  using Brβ . CAVI isρ, density of blood; a, b, correction coefficient.The usefulness of CAVI in the management of patients with hypertensive, diabetic or renal disorders was previously reported in –8, but wThe subjects of this study were 109 Japanese women consisting of 23 nonpregnant healthy women (group A), 45 normotensive pregnant women (group B), 28 pregnant women complicated with established preeclampsia (group C), and 13 pregnant women with chronic hypertension (group D). Eighty-six pregnant women  were patients who visited Mie University Hospital. Twenty-three nonpregnant women (group A) were volunteers including nurses and midwives in Mie University Hospital. All the data in this study were obtained from January 2005 to March 2007. The diagnosis of preeclampsia was made according to the criteria of the International Society for the Study of Hypertension in Pregnancy [β), which expressed blood pressure independent vascular stiffness. Stiffness parameter (β) is calculated as follows:The CAVI is based on the stiffness parameter ; ΔP, pulse puressure; ρ, blood density (1.03 × 103 kg/m3); V, volume of blood vessel; ΔV, change of V.The previous 3 formulas , and C gβ) can be easily calculated by measures of BP and cardioankle PWV. The new index CAVI is expressed as follows:Thus, the stiffness parameter . The CAVI has the great merit that it is not influenced by BP, whereas conventional PWV is strongly influenced by BP. However, CAVI might have an error because of the variety of blood density in each case, where in the formula for calculation of CAVI, a standard value of blood density was used.CAVI has a compatibility with conventional PWV. CAVI is easily measured using Vasera VS-1000 , which is now becoming popular. The CAVI is automatically calculated by the instrument and reflects the stiffness parameter . In all cases, no symptomatic adverse effects were noted by supine position. U-test was used for statistical analysis of comparing values between the two groups. Probability (P) values less than  .05 were considered as significant.Mann-Whitney's Successful recordings were obtained from all women. The demographic characteristics of the study subjects were shown in Significant differences were noted between groups A and C, A and D, B and C, B and D in systolic, diastolic and mean blood pressures. As shown in β, and augmentation index (AI). Carotid-femoral PWV is affected by blood pressure and can be adjusted using a compensating nomogram for blood pressure. However, carotid-femoral PWV requires somewhat complicated technique to obtain an accurate waveform. It is also time-consuming, and it takes approximately 15 to 20 minutes for one measurement. baPWV has been developed, which can be assessed with a simpler technique in a short time using a measurement system but it is strongly affected by the changes in blood pressure during measurement. AI is strongly influenced by heart rate, and it is necessary to correct AI by heart rate for the comparison among subjects. SPβ is a parameter which is independent of blood pressure but requires a long time for the measurement, and the measuring equipment for SPβ (sonographic vessel tracking system) is expensive. Moreover, SPβ is a parameter of the local vessel  and not a systemic vessel parameter.To assess the vascular stiffness, several parameters have been used such as carotid-femoral PWV, baPWV, SPCAVI is thought to be an index which eliminates these defects in the conventional vascular parameters. It was previously reported that CAVI is independent of blood pressure . The meaIn preeclamptic women, no atherosclerotic change of the vessel wall was produced, which is different from the vessel wall in chronic hypertensive women. In our current study, both in preeclamptic and chronic hypertensive groups, baPWV was elevated and no significant difference was noted between the two groups. On the other hand, CAVI was also elevated both in preeclamptic and chronic hypertensive groups, but the elevation was milder in the former group. Significant difference was noted between the two groups.In chronic hypertensive women, blood pressure was elevated and  structural change in the vessel wall may have been produced, resulting in both baPWV and CAVI elevations. In preeclamptic women, blood pressure was elevated and thus baPWV was elevated. In preeclamptic women, lesser vessel wall structural change was produced, and lesser elevation of CAVI was seen, which is lesser influenced by blood pressure elevation than baPWV. From our results, we believe that we can distinguish the vessel structural change between chronic hypertension and preeclampsia through baPWV and simultaneous CAVI measurements.However, if CAVI could be completely independent of blood pressure and could completely reflect the atherosclerotic change of the vessel wall, it might be difficult to explain the reason of significant elevation of CAVI in preeclampsia from normotensive pregnancy. Brodszki and colleagues reported that there were no differences in vessel wall stiffness between women with preeclampsia and healthy controls, through the assessment of common carotid artery, abdominal aorta, and popliteal artery by using ultrasonic echo-tracking system . On the Recently, CAVI, a new index of vascular stiffness, was developed, which is thought to be an index independent of blood pressure. We assessed CAVI in normotensive and hypertensive pregnant women as the world's first report on CAVI in pregnancy. We believe that we can distinguish the vessel structural change between chronic hypertension and preeclampsia through simultaneous baPWV and CAVI measurements.


Among African-Americans adults, arterial hypertension is both more prevalent and associated with more complications than among white adults. Hypertension is also epidemic among black adults in sub-Saharan Africa. The treatment of hypertension among black adults may be complicated by lesser response to certain classes of anti-hypertensive agents.We systematically searched literature for clinical trials of ACE-inhibitors among hypertensive adults comparing blood pressure response between whites and blacks. Meta-analysis was performed to determine the difference in systolic and diastolic blood pressure response. Further analysis including meta-regressions, funnel plots, and one-study-removed analyses were performed to investigate possible sources of heterogeneity or bias.In a meta-analysis of 13 trials providing 17 different patient groups for evaluation, black race was associated with a lesser reduction in systolic (mean difference: 4.6 mmHg (95% CI 3.5-5.7)) and diastolic (mean difference: 2.8 mmHg (95% CI 2.2-3.5)) blood pressure response to ACE-inhibitors, with little heterogeneity. Meta-regression revealed only ACE-inhibitor dosage as a significant source of heterogeneity. There was little evidence of publication bias.Black race is consistently associated with a clinically significant lesser reduction in both systolic and diastolic blood pressure to ACE-inhibitor therapy in clinical trials in the USA and Europe. In black adults requiring monotherapy for uncomplicated hypertension, drugs other than ACE-inhibitors may be preferred, though the proven benefits of ACE-inhibitors in some sub-groups and the large overlap of response between blacks and whites must be remembered. These data are particularly important for interpretation of clinical drug trials for hypertensive black adults in sub-Saharan Africa and for the development of treatment recommendations in this population. Hypertension is a growing problem among black adults worldwide. Black adults have the highest age-adjusted rates of hypertension among all racial groups in the United States of America (USA) and Europe. Among black adults in the USA, for example, 44.4% of men and 43.9% of women have hypertension compared to 33.3% in the general population . Black aIn sub-Saharan Africa, hypertension is epidemic among black adults. Although previously considered rare -6, the pOne frequently cited challenge of treating hypertension among black adults is the lesser blood pressure response to certain medications such as ACE-inhibitors (ACEI) -20. The We systematically searched PubMed, EMBASE and Web of Science for any prospective clinical trials providing race specific data on blood pressure lowering during treatment with ACEIs for adults with arterial hypertension on 3 August 2012. The search strategies were created by practicing clinicians and a research librarian and are provided in the Additional file Once the systematic literature search was complete, two independent reviewers appraised all articles according to a standard set of inclusion and exclusion criteria. In cases of differing results, a third reviewer adjudicated. In the first step, articles were excluded or included based on a review of their titles and abstracts. The remaining articles were then evaluated in full text. All articles fulfilling the below-mentioned criteria were selected and data were extracted.Inclusion/exclusion criteria were as follows. The study must be a prospective clinical trial providing race specific data on blood pressure lowering during treatment with ACEI. Study participants must be aged ≥18 years. Studies were included only if they enrolled patients for treatment of confirmed arterial hypertension. In order to evaluate the pure effect of ACEI therapy itself on blood pressure reduction, studies that used combination therapy were excluded from the analysis. The minimum treatment duration was 4 weeks; the minimum patient number was ten.Two independent reviewers performed data extraction in duplicate. In the case of disagreement, a 3rd reviewer examined the article in order to correct the difference. Data were all entered into a standardized evidence table , average age, age difference between races, gender distribution, ACE-inhibitor used and average dose, time interval between start of treatment and blood pressure measurement. Of note, the Jadad score is a standard measure of the quality of clinical trials ranging from 0  to 5  that takes into account the following components: randomization, blinding, and loss to follow-up . ACE-inhFor one study, two references were used for data extraction ,23. For 2 statistics. We assessed possibility of publication bias by evaluating a funnel plot for asymmetry and by Egger’s regression intercept. To evaluate the possible sources of heterogeneity we performed metaregression and stratification according to the above-mentioned factors. As two studies in the meta-analysis had a much larger sample sizes than the other studies, we performed a one-study-removed analysis to assess whether the removal of any one study changed the overall results of the meta-analysis.The meta-analysis was performed using random effects model. Mean difference and 95% confidence intervals (95% CI) were calculated. We tested for heterogeneity by Q test and IWe hypothesized that black race was associated with a lesser reduction in systolic and diastolic blood pressure in response to ACE-inhibitor therapy. We also hypothesized that possible sources of heterogeneity between studies could include: age, ACE-inhibitor dose, study quality (i.e. Jadad score), treatment duration and/or baseline blood pressure.Our systematic literature search revealed 909 articles: 252 from PubMed, 137 from Embase and 520 from Web of Science. After removal of duplicates, 795 articles were reviewed on the basis of the title and the abstract. This led to the removal of 734 articles. The 61 remaining articles were examined in full text. Of these, 14 fulfilled the inclusion/exclusion criteria. These 14 articles reported 13 different studies and provided 17 different patient groups for evaluation -35. The Table 2 statistic was 24.2 and the Q test was not statistically significant (p = 0.19). The Forest Plot for difference in mean change in systolic blood pressure between whites and blacks is displayed in Figure Data on systolic blood pressure changes were available from 15 patient groups out of 11 studies. In the pooled analysis, white race was associated with a greater reduction in systolic blood pressure (mean difference 4.64 mmHg (95% CI 3.53 - 5.75)). We detected little heterogeneity within this comparison. The I2 statistic was 59.0 and the Q test was statistically significant (p < 0.0001). The Forest Plot for difference in mean change in diastolic blood pressure between whites and blacks is displayed in Figure Data on diastolic blood pressure changes were available from 16 patient groups out of 12 studies. In the pooled analysis, white race was associated with a greater reduction in diastolic blood pressure (mean difference 2.82 mmHg (95% CI 2.17 – 3.47)). We detected some heterogeneity within this comparison. The IIn order to detect potential publication or reporting bias, we performed a separate Funnel Plot analysis for systolic and diastolic blood pressure. Figure We performed meta-regression analysis of age, ACEI dosage, duration of therapy, Jadad score and baseline blood pressure with regard to systolic Figure A and diaAs two studies in the meta-analysis had much larger sample sizes than the other studies, we performed a one-study-removed analysis to assess whether the removal of any one study changed the overall results of the meta-analysis Figure . No chanIn this meta-analysis of 13 unique clinical trials of ACEI therapy for hypertensive adults providing race-stratified systolic and/or diastolic blood pressure results, black race was associated with a consistently lesser response in both systolic and diastolic blood pressure after ACEI therapy (4.6 and 2.8 mmHg respectively). The observed differences in blood pressure response are not only statistically significant but also clinically important since a reduction of 4–5 mmHg in SBP and 2–3 mmHg in DBP has been associated with a 8-20% reduction in risk of cardiovascular morbidity and mortality . This diThe difference in blood pressure response to ACEI monotherapy between blacks and whites observed in this meta-analysis appears to be related to race and is not entirely explainable by other factors. One-study-removed analysis and funnel plots showed no evidence of overinfluence by a single study or of publication bias. We also performed careful metaregression to estimate the impact of possible confounders such as age, baseline blood pressure, duration of treatment, study quality and ACEI dose. Of these factors, only ACEI dose had some mitigating effect on the difference in blood pressure response. Higher doses of ACEI may be beneficial among black adults who require ACEI therapy for hypertension although higher doses may be associated with more adverse effects. One additional, possible confounder in the relationship between race and ACE-inhibitor response is salt intake. Three of the studies included in this meta-analysis investigated the impact of salt intake on the relationship race and ACE-inhibitor with mixed results ,34,35. TThe magnitude of the difference in blood pressure response to ACEI therapy observed in this meta-analysis is quantitatively similar to that observed in other literature. In the largest randomized, controlled trial that compared outcomes to ACEI therapy among black and white adults with hypertension (the ALLHAT study), the differences in systolic and diastolic blood pressure response to lisinopril were 5.6 and 2.5 mmHg respectively , almost It is important to note that the variability of response to ACEI monotherapy is greater within races than between races. As seen in Table Both the USA JNC-7 guidelines and the UK NICE guidelines have noted the difference in in ACEI response between white and black adults ,42. AccoThese findings must also be taken in the context of other clinical trials that have demonstrated the benefit of ACEI therapy among blacks with certain complications such as chronic kidney disease and diabetes mellitus despite lesser reduction in blood pressure . Also, uThis meta-analysis has several important limitations. First, all of the studies included in this meta-analysis except one were done in the USA and therefore may not be applicable to black adults living in other regions such as sub-Saharan Africa. Although this is a limitation, we also believe that this meta-analysis is important in providing context for the much-anticipated results of the first large, randomized, controlled trials of antihypertensive drugs among hypertensive black adults in sub-Saharan Africa . Also, tIn conclusion, this study confirms and quantifies the hypothesis that adult black hypertensive patients do generally have a lesser mean reduction in systolic and diastolic blood pressure response to ACEI monotherapy when compared to whites. This meta-analysis provides evidence for current guidelines that recommend that drugs other than ACEI should be preferred for uncomplicated, mild-moderate hypertension in blacks, guidelines that have particular import in sub-Saharan Africa. These results, though, must be taken in the context of other research that provides strong evidence for the benefits of ACEIs in some subgroups of hypertensive black adults, particularly those with certain complications such as chronic kidney disease and diabetes mellitus and those requiring multi-drug therapy for their hypertension. For hypertensive black adults in whom ACEI monotherapy is indicated, higher doses may be necessary to obtain the desired reduction in blood pressure.ACEI: Angiotensin converting enzyme inhibitors; DBP: Diastolic blood pressure; SBP: Systolic blood pressure; UK: United Kingdom; USA: United States of America.The authors declare that they have no competing interests.RNP conceived of the study, participated in its design and coordination and drafted the manuscript. LRS coordinated data collection and drafted the manuscript. RB participated in the design of the study and assisted in data collection. ACL drafted the manuscript. HG assisted in the analysis and revised the manuscript. DF assisted in the analysis and revised the manuscript. BMWS conceived of the study, participated in its design, and performed the analysis. All authors read and approved the final manuscript.The pre-publication history for this paper can be accessed here:http://www.biomedcentral.com/1471-2369/14/201/prepubSearch Strategies.Click here for fileEvidence Table (after removing data already included in Tables Click here for file


As the vascular endothelium has multiple functions, including regulation of vascular tone, it may play a role in the pathophysiology of orthostatic intolerance. We investigated the effect of orthostasis on endothelial function using EndoPAT®, a non-invasive and user-independent method, and across gender. As sex steroid hormones are known to affect endothelial function, this study examined the potential effect of these hormones on the endothelial response to orthostasis by including females at different phases of the menstrual cycle , and females taking an oral contraceptive. A total of 31 subjects took part in this study . Each subject made two visits for testing; in the case of females having normal menstrual cycles the first session was conducted either 1–7 (follicular) or 14–21 days  after the start of menstruation, and the second session two weeks later, i.e., during the other phase, respectively. Endothelial function was assessed at baseline and following a 20-min orthostatic challenge (active standing). The EndoPAT® index increased from 1.71 ± 0.09 (mean ± SEM) at baseline to 2.07 ± 0.09 following orthostasis in females (p<0.001). In males, the index increased from 1.60 ± 0.08 to 1.94 ± 0.13 following orthostasis (p<0.001). There were no significant differences, however, in the endothelial response to orthostasis between females and males, menstrual cycle phases and the usage of oral contraceptive. Our results suggest an increased vasodilatatory endothelial response following orthostasis in both females and males. The effect of gender and sex hormones on the endothelial response to orthostasis appears limited. Further studies are needed to determine the potential role of this post orthostasis endothelial response in the pathophysiology of orthostatic intolerance. Adoption of an upright posture (relative to gravity) can induce a drop in arterial blood pressure (orthostasis). Failure to maintain mean arterial blood pressure can lead to reduced cerebral blood flow, which can precipitate dizziness or even syncope in susceptible (orthostatic intolerant) individuals, and astronauts returning to Earth. Numerous mechanisms appear to underlie orthostatic intolerance see . For insMechanical stress of the endothelium has been associated with the release of numerous  vasoactive substances ,6. Shear® uses beat-to-beat plethysmographic assessment of PWA to calculate the reactive hyperaemic index (RHI); the ratio of digital pulse volume during reactive hyperaemia and the baseline [®.A novel non-invasive and user-independent method of assessing endothelial function via (finger) peripheral arterial tonometry (PAT) has been proposed where pulse wave amplitude (PWA) changes are significantly associated with FMD . The Endbaseline . ComputeGender appears a significant factor in determining an individual’s susceptibility to orthostatic intolerance ,14. A st®, to specifically investigate the: 1) effect of orthostatic challenge on endothelial function; 2) whether it differs according to gender; 3) and if sex steroids modify such an effect, by studying responses in a) females in the follicular and luteal phase of the menstrual cycle, where estrogen levels differ and b) females on the oral contraceptive pill (OCP).This study, therefore, utilised the EndoPAT31  healthy 1, un-trSubjects with histories of vasovagal syncope, vertigo and vestibular disturbance as well as cardiovascular, respiratory and neurological diseases were excluded from the study. The subjects were anonymised during data analyses. In addition, data are stored according to the National Data protection data at the institute, where the experiments were done. These data are not publicly deposited.follicular: 1-7 days after the start of menstruation or luteal: 14-21 days after the start of menstruation) and the second session two weeks later. Females on the OCP in this study were either on the combined pill or were on Progesterone only pill. Subjects were tested at the same time of day between 10 am -1 pm in both sessions within a quiet darkened room maintained at ~23° C and 55% humidity.Each subject attended two experimental sessions at the Institute of Physiology, Medical University of Graz separated by 2 weeks having been instructed to refrain from exercise and caffeine consumption for >12 hours prior to testing. For females not taking the OCP, the first session was conducted in one phase of the menstrual cycle . Subjects then performed the 20 min stand test (on a flat posturography plate) during which blood pressure was checked at regular intervals before returning to the supine position where endothelial function and blood pressure were reassessed (post). Data for blood pressure and posturography will be reported elsewhere.Each subject had an initial (pre) blood pressure measurement made when supine. The recorded individual systolic blood pressure values were used to calculate the suprasysolic values (20 mmHg above the sysolic pressure) to which the sphygmomanometer cuff was inflated (see below). After blood pressure measurements, no measurements were done for 20 min. Then the endothelial function was assessed using EndoPAT®  with the subject in the supine position and the hands elevated  so the fingers were hanging freely and a plethysmographic biosensor (finger probes) was applied to each index finger connected to the EndoPAT2000® via flexible tubing. A standard blood pressure cuff  was placed around the left upper arm.Endothelial function was assessed using the EndoPAT2000supra-systolic pressure), thus occluding forearm blood flow , the blood pressure cuff was inflated to 20mmHg greater than each subject’s systolic blood pressure (trol arm 1). The Orthostatic challenge was generated via an active stand test where subjects stood on a horizontal surface (posturography plate) for a period of 20 min. Each subject was monitored closely for symptoms of presyncope, which would have led to experimental termination. However, no subject experienced presyncopal symptoms and thus all test subjects completed the entire protocol.post) from both fingers, thereby correcting for any systemic vascular changes resulting from flow occlusion in the measurement arm.In addition to real-time viewing of the PAT signal the software generated the EndoPAT/Reactive Hyperemia Index (RHI) which represents a ratio of the average pulse wave amplitude a 210s (baseline) prior to the blood pressure cuff being inflated vs. 60s after the release of the blood pressure cuff (Changes in EndoPAT index are expressed as changes in mean (± SEM). Two factor ANOVA, with a Bonferroni post-hoc test, was used to obtain the effects of both orthostasis and gender on the EndoPAT index. Similar statistical analysis was used for the EndoPAT data from females relevant to phase of the menstrual cycle as well as whether they were taking the pill or not.The changes in EndoPAT index to orthostasis were measured in 11 males and 20 females, during the two visits 2. In feThere were no differences in the baseline EndoPAT index readings between females and males. Similarly, there were no significant differences in the post orthostasis EndoPAT RHI values between the sexes (p=0.47).In females the degree of change in EndoPAT RHI post orthostasis was comparable in the two menstrual cycle phases (n = 11) 2. DurinAltogether nine subjects on the OCP were studied. All of these were on combined OCP or progesterone only pill. Out of these subjects, however, the OCP phase, inferred from the time of their first day of menstrual bleeding, was only available in seven subjects. In these seven subjects 3, the iThis study shows that 20 min period of orthostatic challenge increases the vasodilator endothelial response, as evidenced by an increased EndoPAT index post orthostasis (confirming hypothesis 1). In addition, the endothelial response to changes of posture from supine to standing was also observed in both females and males. To our knowledge we are not aware of any study that investigated endothelial vascular responses following 20 min of active standing and across gender, using the non-invasive and operator independent EndoPAT®.The increased vasodilatory response seen post orthostasis represents increased action of NO. One possibility for this increased action is that on standing, the gravitational effects on blood causes pooling in the extremities. This may be seen to increase shear stress on the endothelium, promoting NO release. Studies have also shown an interaction between the sympathetic nervous system and NO action. It is believed that NO may act in modulating sympathetic vasoconstriction, by increasing basal vasodilatory tone ,22. The ® device in showing changes in vasodilatory endothelial function in keeping with previous literature is important. As it is not user dependent, it helps to confirm the response to orthostasis seen before. In addition, given that it has clear advantages in terms of ease of use and non-operator dependence, it may be useful in future studies in this area.Previous studies have looked at the effect of orthostasis on endothelial function. For instance, brachial artery flow mediated dilatation was assessed in 21 males following 60° head up tilt (HUT). The results showed an increase in flow-mediated dilatation in the HUT position compared to baseline . This suGiven the increased susceptibility of females to orthostatic intolerance –16, thisOur study investigated the endothelial response to orthostasis in the follicular and luteal phases of the menstrual cycle. A previous study used brachial artery mediated dilatation on premenopausal women at various stages of the menstrual cycle to assess the effect on endothelial function . ResultsSimilarly in this study we did not see any differences in the endothelial responses to orthostasis when females taking the OCP were in the placebo or the active phase. As in the case of the luteal phase of the menstrual cycle, it may have been expected that the response to orthostasis would be greater in the active phase. Interestingly, other studies looking at the effects of the OCP on the endothelium have reported widely varying and often contrasting results. A small study involving 12 females found that endothelial function, measured with brachial artery flow mediated dilatation was greater during the active phase than the placebo phase . ConversA limitation of this study is that we did not include a post-menopausal group. Despite the fact that males have lower estrogen levels than females, the breakdown of testosterone in males to estradiol means it may still be having an effect. Having a post menopausal group would have allowed study in subjects not under the effects of sex steroids, in particular estrogen. This may have better elucidated the importance of sex steroids in the endothelial response to orthostasis.® device could provide a less technically difficult, user-independent and mobile way to measure endothelial function in future studies.This study shows that there is an increased vasodilatory endothelial response following a period of orthostasis in both females and males. The EndoPATGender and sex hormones appear to have limited effect of the endothelial response to orthostasis. Further work including post menopausal women and blood sampling would be needed to understand the role of sex steroid hormones and their relationship to orthostatic tolerance.Further studies need to be done to see if exposures to microgravity or bed rest induced deconditioning lead to exaggerated vasodilatory endothelial response to orthostasis. Given that the endothelial response may be modulating the sympathetic response to orthostasis, an exaggerated endothelial response may overcompensate for the sympathetic drive. Thus the endothelium may play a role in the pathophysiology of orthostatic intolerance in returning astronauts or in bedrest deconditioned subjects.


Working mostly at night has been suggested to be associated with upset of chronobiological rhythms and high blood pressure, but the evidence from epidemiological studies is weak.In a cross-sectional survey, we evaluated the association between shift work and blood pressure, pre-hypertension and hypertension. In total, 493 nurses, nurse technicians and assistants, were selected at random in a large general hospital setting. Hypertension was diagnosed by the mean of four automatic blood pressure readings ≥140/90 mmHg or use of blood pressure lowering agents, and pre-hypertension by systolic blood pressure ≥120–139 or diastolic blood pressure ≥80–89 mmHg. Risk factors for hypertension were evaluated by a standardized questionnaire and anthropometric measurements. The association between the shift of work and blood pressure, pre-hypertension and hypertension was explored using univariate and multivariate analyses that controlled for risk factors for hypertension by covariance analysis and modified Poisson regression.The mean age of the participants was 34.3±9.4 years and 88.2% were women. Night shift workers were older, more frequently married or divorced, and less educated. The prevalence of hypertension in the whole sample was 16%, and 28% had pre-hypertension. Blood pressure (after adjustment for confounding) was not different in day and night shift workers. The prevalence of hypertension and pre-hypertension by shift work was not different in the univariate analysis and after adjustment for confounding .Night shift work did not increase blood pressure and was not associated with hypertension or pre-hypertension in nursing personnel working in a large general hospital. Working mostly at night has been suggested to be associated with deleterious consequences of general health, as a consequence of disturbance of chronobiological rhythms Despite the biological plausibility and evidence from short term studies, there is very few evidence that acute changes in blood pressure regulation in shift workers lead to chronic hypertension. Epidemiological studies linking shift work to the risk for hypertension are few, old and of questionable quality. Two recent and better designed studies found opposite effects. In a Japanese cohort study, habitual shift workers of a steel company had higher systolic and diastolic blood pressure than habitual daily workers The aim of the present study was to investigate the association between shift work and the prevalence of hypertension and pre-hypertension in the nursing staff of a general hospital.The Review Board of the Hospital São Vicente de Paulo from the University of Passo Fundo approved the investigation, and all participants gave their written consent to participate.Nursing personnel  of a large general hospital , Passo Fundo, Brazil, were selected at random during the periodic medical examination between January 2008 and August 2009. A total of 493 individuals, predominantly women (88.2% vs. 11.8%), aged from 19 to 68 years agreed to participate.A standardized questionnaire was used to investigate aspects pertaining to shift working and other risk factors for hypertension. Certified investigators interviewed the participants at the place of work, using a manual with instructions for every section of the questionnaire and for blood pressure and anthropometric measurements. Ten percent of the interviews were repeated at random for quality assurance, and the data were entered in duplicate.Demographic , socioeconomic , and lifestyle  characteristics were recorded. Individuals were categorized as current smokers or non-smokers (never smokers or ex-smokers). The pattern of alcohol consumption in the previous year was investigated by a type/frequency questionnaire. The risk of alcoholic beverages consumption was defined by a binge drinking pattern, i.e., 5 or more glasses of drinking in one occasion. Skin color was categorized as white or non-white. Years at school were categorized as more or less than 8 years. Sleeping hours corresponded to the hours of sleep during 24 h in a typical week.Shifts of work were characterized as morning, afternoon, and night and the combination of them. Since just a few worked exclusively afternoon shifts, this category was combined with the morning shift.Blood pressure was measured four times during the interview, using an automatic device (OMRON CP-705), and the average was used in the analyses. Hypertension was defined by systolic blood pressure ≥140 or diastolic blood pressure ≥90 mmHg, or use of blood pressure-lowering drugs. Pre-hypertension was defined by systolic blood pressure ≥120–139 or diastolic blood pressure ≥80–89 mmHg.Weight was measured within 100 g intervals and height within 0.1 cm using a scale with a stadiometer , with the participants wearing light clothes and without shoes. Body mass index (BMI) was calculated by dividing weight by height squared.The sample size calculation was done with the Epi-Info software, version 6.04. Assuming a prevalence of hypertension of 14% in daily workers and an increase to 25% in workers in the night shift, a power of 80% and confidence limits of 95%, the sample size was estimated as 486 to reject the null hypothesis. Proportions were compared by Chi-square test and means by the Student t-Test for independent samples. Multivariate analyses were carried out using co-variance analyses and Modified Poisson regression.Among 2,140 employees of the hospital, 862 (23.1%) were nurses, nurse technicians or nurse assistants. From these, 493 (57.1%) were selected at random, and none refused to participate. The prevalence of hypertension was 16%, and 28% of the participants had pre-hypertension. This cross-sectional survey of a representative sample of the nursing staff of a large general hospital demonstrated that the shift of work was not associated with the magnitude of blood pressure or prevalence of hypertension. The absence of association was confirmed by multivariate analyses and was not influenced by longer periods of total sleep during a typical work week for the nurses that worked the night shift. Traditional risk factors, such as age and BMI, were associated with a higher prevalence of hypertension.Short term studies with small samples have identified a trend towards higher blood pressure among shift workers The absence of blood pressure measurements during sleep with an Ambulatory Blood Pressure machine and the lack of an objective evaluation of sleep disorders are possible limitations of our study. The cross-sectional design is not the strongest design to establish the risks of shift work for chronic hypertension, but the absence of any cross-sectional association makes it unlikely that we missed an increase in blood pressure that would develop over time. The fact that the study was limited to nurses makes it impossible to exclude the possibility that hypertension could be linked to shift work in other professions. The prospective planning, adequate power, careful measurement of blood pressure, and evaluation of risk factors for hypertension are strengths of our survey.In conclusion, night shift work was not associated with an increase of blood pressure, hypertension or pre-hypertension in the nursing staff of a general hospital.


Currently, a non-invasive method to estimate the degree of interstitial fibrosis (IF) in chronic kidney disease is not available in routine. The aim of our study was to evaluate the diagnostic performance of the measurement of urinary low molecular weight (LMW) protein concentrations as a method to determine the extent of IF. The urines specimen from 162 consecutive patients who underwent renal biopsy were used in the analysis. Numerical quantification software based on the colorimetric analysis of fibrous areas was used to assess the percentage IF. Total proteinuria, albuminuria, and the urinary levels of retinol binding protein (RBP), alpha1-microglobulin (α1MG), beta 2-microglobulin (β2MG), transferrin, and IgG immunoglobulins were measured. There was a significant correlation between the degree of IF and the RBP/creatinine (creat) ratio . IF was associated to a lesser extent with urinary β2MG and α1MG; however, there was no association with total proteinuria or high molecular weight (HMW) proteinuria. The correlation between IF and RBP/creat remained significant after adjustment to the estimated glomerular filtration rate, age, body mass index, α1MG, and β2MG. The specificity of the test for diagnosing a fibrosis score of >25% of the parenchyma was 95% when using a threshold of 20 mg/g creat. In conclusion, RBP appears to be a quantitative and non-invasive marker for the independent prediction of the extent of kidney IF. Because methods for the measurement of urinary RBP are available in most clinical chemistry departments, RBP measurement is appealing for implementation in the routine care of patients with chronic kidney disease. Kidney disease evolution invariably lead to interstitial fibrosis (IF), which is the main factor contributing to kidney structural deterioration and loss of function The development of non-invasive biomarkers of kidney status and outcome is challenging but can result in individualized therapies for patients with chronic kidney disease (CKD) In this study, we have hypothesized that IF (independent of the cause) promotes a defect in the proximal reabsorption of LMW proteins and that the urinary concentration of these proteins is an indication of the extent of kidney fibrosis. To test this hypothesis, we measured the urinary concentration of LMW proteins , HMW proteins , and total proteins in 189 consecutive patients who underwent a kidney biopsy. Next, we measured the strength of the association between these proteins and the percentage IF, measured using a color segmentation image analysis technique. Our data indicated that the urinary concentration of LMW proteins was positively correlated with the degree of IF, and urinary RBP was independently associated with the extent of IF in CKD patients.Between March 2012 and March 2013, 189 consecutive patients who were referred to the Nephrology Department at the Georges Pompidou European Hospital  for kidney biopsy were evaluated for potential inclusion in the study. Indications for biopsy were estimated GFR<60 ml/min and/or proteinuria>0.5 g/l. Kidney biopsies were not performed for the purpose of this non interventional study, but only for patient care. We excluded from the study all patients with acute kidney injury and KTRs. At the time of biopsy, urine and blood samples were collected for routine clinical chemistry analyses and stored at −80°C. Detailed information regarding the clinical, medical, demographic, biological, and histological status of the patients was collected using an information-based data warehouse The urine protein measurements were performed at the Clinical Chemistry Department of the European Georges Pompidou Hospital. The urinary total protein concentration was quantified by measuring pyrogallol red at 600/800 nm absorbance , and the Alb concentration was measured by immunoturbidimetry analysis  using a Beckman Coulter AU680 analyzer. The urinary levels of α1MG, β2MG, TRF, RBP, and IgG were measured using a Siemens BN II nephelometer Analyzer II and kits from Siemens. Values considered normal were as follows: α1MG<15 mg/L; β2MG<350 μg/L; RBP<0.5 mg/L; TRF<2.2 mg/L, IgG<3.6 g/L, and Alb<20 mg/L http://links.lww.com/TP/A493).Masson's trichrome-stained kidney sections were analyzed using color segmentation image analysis software for the quantification of IF 2), where appropriate. The variables correlating with the extent of IF by univariate analysis were included in a multivariate linear regression model. The variables correlating with the extent of IF by univariate analysis were included in a multivariate linear regression model. To check that despite this overlap RBP can help improve the prediction of fibrosis, we fitted and compared two linear models, one including known predicting factors alone  and one including both these factors and RBP. The two models were compared based on a Likelihood ratio test, where the deviance follows a Chi-square distribution with number of degrees equal to the difference of included variables in the two nested models. A backward stepwise linear regression analysis was used to identify the clinical factors independently associated with the extent of the IF. Power calculation is not necessary, because our principal objective was not to compare two groups of patients towards an end point to test the null hypothesis, with an alpha and beta risk. Rather, we performed uni and multivariate linear regression analysis; and we evaluated the performance of a diagnostic biomarker. The statistical analyses were performed using the R framework (http://www.R-project.org/).The results were expressed as the frequencies and percentages for the categorical variables and as the mean ± SEM for the continuous variables. Associations between the clinical and biological features of the patients were tested using the Student T test, Mann-Whitney test or through the estimation of the Pearson correlation coefficient . Advanced kidney disease was common; more than 50% of the patients exhibited an eGFR <30 ml/min . The demographic and medical characteristics of the remaining 162 patients are listed in 0 ml/min Fig. 1A., , Fig. S1A-C). As expected, HMW proteinuria was significantly higher in patients with glomerular disease compared to patients with tubular and vascular diseases , whereas LMW proteinuria was higher in patients with tubular disease compared to patients with vascular and glomerular diseases . Although a higher IgG concentration was expected in patients with glomerular disease .We characterized the proteinuria expression patterns in the 162 CKD patients. The LMW proteins strongly correlated with each other but not with the HMW proteins and total proteinuria  compared to the patients with eGFR values >30 ml/min, whereas HMW and total proteinuria were not significantly different among the eGFR groups . These data indicated that LMW proteinuria but not total or HMW proteinuria was a characteristic of patients with low eGFR in this CKD population.The distribution of proteinuria according to the eGFR levels was analyzed. LMW proteinuria was significantly higher among the patients with a mean eGFR value <30 ml/min   , Table 22 = 0.11, p<0.0001); α1MG ; and β2MG  . This association was significant in patients with glomerular disease  but not in patients with tubule-interstitial disease  or vascular disease  despite a clear trend .We next examined the association between LMW proteinuria and the extent of IF. The univariate analysis indicated that LMW proteinuria but not HMW or total proteinuria correlated significantly with the extent of IF; RBP , demonstrating that RBP was independently correlated with the extent of IF.Finally, we analyzed the efficiency of testing urinary RBP levels for diagnosing the extent of IF. RBP/creat ratio has a high specificity in detecting cases with >25% fibrosis . This raises the question of the prognostic value of RBP of the decline of renal function, which remains to be examined. Our results suggest that IF promotes loss of function and eGFR decline, and IF promotes tubular dysfunction and RBP loss. This point is supported but the results of the regression analysis indicating that RBP and GFR correlate with IF, and that RBP is independent of GFR.The proposed rationale for the detection of increased LMW protein concentrations in the urine from patients with extended fibrosis of the kidneys is based on the hypothesis that IF is frequently associated with TA, leading to the defective proximal reabsorption of physiologically filtered LMW. Any increase in the urinary excretion of β2MG or RBP is highly specific for tubular disease, whereas the increased excretion of α1MG is observed in glomerular proteinuria An advantage of our study is that the large panel of proteins tested in our center used validated methods used routinely in clinical chemistry laboratories, and the cost was relatively low (7 USD per RBP measurement). In comparison, the cost of a urinary electrophoretic profile is 10.5 USD and an albuminuria measurement is 3 USD. Importantly, the performance of these methods has been validated, including the interlaboratory reproducibility of the tests, and the practical outcome is that almost all clinicians can evaluate the extent of IF in CKD patients through measuring the RBP concentration We observed that RBP correlated with IF in sthe group of patients with glomerular disease but not in the patients with tubular or vascular disease. Despite this clear trend, the lack of a positive correlation in these two disease categories may be explained by the relatively low size of these subgroups of patients compared with the glomerular disease subgroup. Additionally, this finding may indicate that the tubule-interstitial injury induced by proteinuria secondary to glomerular disease impedes LMW reabsorption to a greater extent than in primitive tubulo-interstitial diseases. Recently, the effect of LMW proteinuria on the prognosis of glomerular disease was highlighted in a study of membranous nephropathy, demonstrating that LMW proteinuria is associated with the progression of kidney dysfunctionAnother intriguing finding was the pattern of urinary IgG expression, which, in contrast to previous studies in KTRs and membranous nephropathies TA has not been evaluated in this study because to our knowledge, there is no validated automatized method for TA quantification in kidney tissue, and there is a need for tools providing continuous values of TA rather that semi-quantitative score. The only validated system of TA scoring is the Banff system, which is widely used, but with numerous limitations, and provides validated information in kidney transplant patients only. There is always a strong correlation between IF and TA scores in models in which they have be evaluated, mostly in kidney transplant recipients, which indicates the score of IF in somehow reveals the TA. The absence of TA measurement does not change the conclusion of our study regarding the performance of the measurement of the concentrations of RBP in urines in predicting the extent of IF.In conclusion, we demonstrated that an increase in the excretion of LMW proteins, particularly RBP, is a non-invasive marker that can independently predict the extent of kidney IF. However, further studies are needed to validate our findings. Because the measurement of RBP is implemented routinely in clinical chemistry departments, RBP is an appealing marker to assess the severity of chronic kidney damage. Studies are ongoing to determine whether LMW protein levels independently predict CKD progression.Figure S1Distribution of proteinuria in the 162 CKD patients. A,B,C. Best-fit slope of linear regression between α1MG and RBP (A), TRF and RBP (B), and proteinuria and RBP (C). D, E, F, G. Histograms showing TRF (D), α1MG (E), β2MG (F) and total proteinuria (G) values according to the type of kidney disease. Protein concentrations are expressed as mean±sem. *p<0.05, **p<0.01, ***p<0.001, compared to glomerular disease, Student T test, except Mann-Whitney test for Glomerular vs Non specific comparison and ANOVA for (G). Glom =  glomerular disease; Tub-Int =  tubular and interstitial diseases; Vasc =  vascular diseases; Non-spe =  non-specific lesions.(EPS)Click here for additional data file.Figure S2Distribution of proteinuria according to estimated glomerular filtration rates. Histograms showing α1MG (A), β2MG (B), IgG (C) and TRF (D) values according to the type of kidney disease. Protein concentrations expressed as mean±sem. *p<0.05, **p<0.01, ***p<0.001, as compared to eGFR<30 ml/min.(EPS)Click here for additional data file.Figure S3Correlation between proteinuria and the extent of interstitial fibrosis. Best-fit slopes of linear regression between α1MG (A), β2MG (B), TRF (C), IgG (D), and proteinuria (E) and the extent of interstitial fibrosis.(EPS)Click here for additional data file.Figure S4Correlation between proteinuria and the extent of interstitial fibrosis according to the type of nephropathy. Best-fit slope of linear regression between fibrosis extent and RBP according to the type of nephropathy: glomerular (A), tubular (B), and vascular (C).(EPS)Click here for additional data file.