Blood pressure variability (BPV) is related to cerebral white matterhyperintensities (WMH), but longitudinal studies assessing WMH progression arescarce. Patients with cardiovascular disease and control participants of theHeart-Brain Connection Study underwent 24-hour ambulatory blood pressuremonitoring and repeated brain MRI at baseline and after 2 years. Using linearregression, we determined whether different measures of BPV , variabilityindependent of the mean) and nocturnal dipping were associated with WMH andwhether this association was mediated or moderated by baseline cerebralperfusion. Among 177 participants ,the absence of diastolic nocturnal dipping was associated with higher WMH volumeat baseline , but not with WMH progression among91 participants with follow-up imaging. None of the BPV measures were associatedwith baseline WMH. Only 24-hour diastolic ARV was significantly associated withWMH progression , most profound in participantswith low cerebral perfusion at baseline (p-interaction = 0.042). In conclusion,absent diastolic nocturnal dipping and 24-hour diastolic ARV were associatedwith higher WMH volume. Whilst requiring replication, these findings suggestthat blood pressure patterns and variability may be a target for prevention ofsmall vessel disease. Hypertension is one of the most important risk factors for WMH.2 Intensive blood pressurelowering therapy slows the progression of WMH by about 40%, as compared withstandard blood pressure lowering therapy,35 but other measures are neededto further reduce WMH accumulation. Increased blood pressure variability (BPV) andan abnormal circadian blood pressure rhythm have emerged as risk factors for strokeand subclinical vascular brain injury.7White matter hyperintensities (WMH) on brain MRI mark the degree of cerebral smallvessel disease (SVD) and are associated with an increased risk of stroke andcognitive impairment. However, results were heterogeneous and longitudinal studies are scarce,making it difficult to determine causality. BPV can be expressed through several indices, such as standard deviation (SD)or average real variability (ARV). Reported indices vary considerably acrosspublished studies, and although there is some evidence to suggest ARV may be most suitable for24-hour BPV, there are no formal guidelines on preference of one over the other. Argumentsin favour of the ARV include its relative robustness to measure BPV irrespective ofthe physiological decrease in blood pressure that occurs at night as part of thenormal circadian rhythm . Alterations in the circadian blood pressure rhythm due to autonomic orendocrine dysfunction may lead to the attenuation or absence of the normalphysiological nocturnal dip. Measurement of 24-hour BPV can be influenced by changesin these nocturnal blood pressure patterns, and ARV is the most robust of indices todetermine BPV irrespective of this nocturnal decrease in blood pressure.A recent meta-analysis of 27 imaging studies showed that increased 24-hour BPV wasassociated with an increased burden of SVD on brain MRI.914 One population-basedlongitudinal study in China showed that non-dippers had a significantly higherincrease in WMH volume over time, but whether this translates to non-Asian populations and patients withcardiovascular disease is undetermined.Although BPV overall is associated with more SVD, not all variation in blood pressureis harmful, and nocturnal dipping, as mentioned, is part of the physiological,normal circadian rhythm. Indeed, several cross-sectional studies have shown that theabsence of nocturnal dipping is associated with an increased volume ofWMH.1618 Sudden decreases in bloodpressure with higher BPV could lead to periodic cerebral hypoperfusion andsubsequently an increased burden of SVD. Such changes in blood pressure may be particularly detrimental in patientswith already compromised cerebral perfusion. For example, with concomitantobstructive carotid artery disease or heart failure, BPV may put additional strainon the brain and result in more vascular brain injury. Yet, these hypothesis remainto be tested in studies investigating cerebral perfusion in the context of BPV,nocturnal dipping and WMH.Despite the link between BPV and WMH, the pathophysiological mechanisms that explainthese associations remain uncertain, in particular regarding blood pressure dynamicsand the role of cerebral (hypo)perfusion.We aimed to determine whether BPV and nocturnal dipping, assessed with 24-hourambulatory blood pressure monitoring (24-hour ABPM), are associated with theprevalence and progression of WMH volume in a longitudinal study of participantswith cardiovascular diseases. We hypothesized that increased BPV and the absence ofnocturnal dipping is associated with increased prevalence and progression of WMHvolume, and explored the role of cerebral perfusion in these associations. A detailed description of the rationale, inclusion and exclusion criteriahas been published previously. In brief, the cohort is composed of 566 participants aged >50 years,who were diagnosed with vascular cognitive impairment (VCI) (N = 166), carotidocclusive disease (COD) (N = 109) or heart failure (HF) (N = 162). Participantswere included between 2014 and 2019 in four participating university medicalcentres in The Netherlands. We also included 129 control participants. Allparticipants were independent in activities of daily life and able to undergocognitive testing. Follow-up examination took place after two years.This study is part of the Heart-Brain Connection Study, which is a multicentre,prospective, observational study that aims to determine the relation betweencardiovascular disease and cognitive impairment, with a focus on hemodynamic factors.From June 2015 onward, participants were asked to undergo 24-hour ABPM in threeout of four participating centres. Patients included prior to June 2015 wereinvited for ABPM at their two year follow-up visit. For the present study, weincluded all participants with a valid 24-hour ABPM at either time point . For theThe Heart-Brain Connection Study was approved by the medical ethics committee ofLeiden University Medical Centre (P14.002) in agreement with the Declaration ofHelsinki. Local medical ethics committees of all sites approved the localperformance of the study. All participants provided written informedconsent.Data are available upon reasonable request. All data relevant to the study areincluded in the article or uploaded as online supplemental information. Requestsfor access to the data reported in this paper will be considered by thecorresponding author. Measurements were initiated during the visit to the research facility andare thus performed on the same day as the brain MRI. Blood pressure was measuredevery 20 minutes during daytime (06.00–22.00 hours) and every 60 minutes duringnighttime (22.00–06.00 hours). A 24-hour ABPM measurement was considered to bevalid, if it had at least 70% valid readings, in line with prior recommendations.Blood pressure was measured non-invasively during 24-hours with validated bloodpressure monitors .23x can be estimated by We calculated mean 24-hour systolic (SBP) and diastolic blood pressure (DBP) anddifferent indices of BPV: SD, coefficient of variation (CV), ARV and variabilityindependent of the mean (VIM). We used the following formulas to calculate theseindices. We therefore report ARV among the main results, with other indicespresented in the supplementary files. BPV was calculated over 24-hours, as wellas stratified by daytime (09.00–21.00 hours) versus nighttime (01.00–06.00hours). We also calculated the extent of nocturnal dipping by using thefollowing formula: mean nighttime blood pressure/mean daytime bloodpressure.Of these four indices, ARV has been suggested as the preferred measure to asses24-hour BPV.Participants provided a list of their medication, from which we derived the useof blood pressure lowering medication. Administration time of the blood pressurelowering medication was not available. Medication was continued during ABPM.Hypertension was defined as a self-reported history of hypertension or use ofblood pressure lowering medication.3,magnetization-prepared rapid acquisition gradient echo, repetition time 8.2 ms,echo time 4.5 ms, shot interval 3000 ms, flip angle 8°, inversion delay 990 ms),a fluid-attenuated inversion recovery (FLAIR) sequence  and 2Dphase-contrast flow measurements . WMH volume was determined by applying an automated brain tissue and WMHsegmentation method  to the T1-weightedseries and FLAIR images. WMH segmentations were manually corrected for brain infarcts and volumeswere expressed as percentages of total intracranial volume (ICV).In all centres, brain MRI was performed on 3 T scanners  using an eight channel, dual or multihead coil. Participants were scanned on the same scanner and coil duringbaseline and follow-up examination according to a standardized protocol thatincluded a T1-weighted series was then calculated by adding up the volume flow rates through the threevessels. Cerebral perfusion (in ml/min/100 ml) was obtained by dividing thetotal CBF by the participant’s brain volume and multiplying the result by 100.Cerebral perfusion was then converted into ml/min/100 g by dividing it by thepartition coefficient of 0.90.Cerebral blood flow (CBF) was determined with 2D phase-contrast flow measurementsin the internal carotid and basilar arteries.Smoking status, either current, former or never, was recorded. Hyperlipidaemiawas defined as a self-reported history of hyperlipidaemia or the use of lipidlowering medication. Diabetes mellitus was defined as a self-reported history ofdiabetes mellitus or the use of anti-diabetic medication. A history ofcerebrovascular or cardiovascular disease was defined as a self-reported historyof ischemic stroke, transient ischaemic attack, myocardial infarction orperipheral arterial disease. Height and weight were measured during the studyvisit and were used to calculate the body mass index.All data were complete with the exception of three participants in whom no dataon cerebral perfusion were available. Nocturnal dipping (night/day ratio) wasanalysed as a continuous variable. Mean 24-hour blood pressure, BPV indices andnocturnal dipping were standardized. WMH volume was expressed as the percentageof ICV and subsequently natural log-transformed to achieve a normal distributionof the data. We assessed normality by visual inspection of Q-Q plots andhistograms.We analysed the association between BPV indices and nocturnal dipping asdeterminants and the normalized, transformed WMH volume as outcome measure withmultiple linear regression, computing both crude estimates and adjustedcoefficients with corresponding 95% confidence interval (CI). In thecross-sectional analyses, we adjusted for age, sex, mean 24-hour SBP or DBP , use of blood pressurelowering medication and body mass index. In the longitudinal analyses, we tookthe normalized, transformed WMH volume at follow-up as the dependent variablewhile adjusting for the baseline normalized, transformed WMH volume. In asensitivity analysis, we defined progression of WMH as an increase in normalizedWMH volume exceeding the median increase in the cohort  andperformed logistic regression to determine if BPV was associated with WMHprogression. We also performed a sensitivity analyses in which we excludedparticipants using beta-blockers as blood pressure lowering medication, becausethose are associated with the highest 24-hour BPV.Analyses were performed in the pooled sample of the four participant groups. Thisis of particular interest because BPV and nocturnal dipping may have ahemodynamic impact, which could be most pronounced in the hemodynamicallyvulnerable participants of all subgroups. We checked for effect modification byparticipant group  by includinginteraction terms  in the model.In case of significant differences in effects between groups, stratified resultswere obtained.Finally, we investigated the role of baseline cerebral perfusion as a potentialmediator  or moderator (by adding aninteraction term to the model) in the association between BPV or nocturnaldipping and progression of normalized, transformed WMH.A p-value < 0.05 was considered statistically significant. Analyses wereperformed in SPSS version 26 and figures were made in R version 4.0.3 (packageggplot2 version 3.3.5). For the mediation analyses, the PROCESS tool for SPSSversion 3.5.3 was used.Of 254 eligible individuals who underwent 24-hour ABPM, 184 participants had ≥70%valid readings on the ABPM. Of those, we excluded 6 participants with poor qualitybrain MRI and 1 participant with a missing covariate, leaving 177 participants(69.7%) for analysis .BPV increased with age , but did notcorrelate significantly with nocturnal dipping . BPV was not significantly differentbetween participants with and without hypertension . Median WMH volume was 1.09 (IQR 0.42–5.61) ml, corresponding with 0.08(IQR 0.03–0.41) % of the ICV. Baseline characteristics per participant group  are shown in Supplementary Table 2.The mean 24-hour SBP and DBP were significantly associated with WMH volume atbaseline after accounting for potential confounders . Twenty-Associations were broadly similar across participant groups, with the exceptionof the association of nighttime DBP ARV with WMH, which was different for thepatients with VCI compared to the other groups .The sensitivity analyses excluding participants using beta-blockers showedcomparable findings (Supplementary Table 4).After a median 2.1 years of follow-up (IQR 2.1–2.3), 91 participants underwentrepeated MRI. Participants with repeated MRI had a higher mean 24-hour SBPcompared with participants who did not have a follow-up visit (SupplementaryTable 5). WMH volumes increased on average by 0.22 (IQR 0.00–1.06) ml,corresponding with an increase of 0.02 (IQR 0.00–0.08) % of the ICV. The averageincrease in WMH volume did not differ significantly between the four participantgroups (Supplementary Table 2).Higher mean 24-hour SBP was significantly associated with increased WMH volumeprogression after accounting for potential confounders. Twenty-four hour anddaytime DBP ARV were significantly associated with progression of WMH volume inthe unadjusted model . This waAssociations with WMH progression were similar across the different participantgroups, except for the association of nighttime SBP ARV with WMH progression.More nighttime SBP ARV related to significantly more WMH progression in the VCIparticipants, but not in the other groups .In the sensitivity analysis with WMH volume progression as a dichotomous outcomevariable, 24-hour and daytime DBP ARV related to a 40% (CI 95% −17 to 136%) and55% (95% CI −8 to 160%) increased risk of WMH progression, respectively, albeitnot statistically significant (Supplementary Table 7). When excludingparticipants using beta-blockers, the effect estimate of 24-hour DBP ARVsomewhat increased , while the othereffect estimates remained approximately unchanged (Supplementary Table 8).Cerebral perfusion was not associated with progression of WMH over time  versus extensive WMH (Fazekas 2–3).30 A longitudinal population-based study also found that daytimesystolic SD resulted in increased progression of WMH after 5 years of follow-up. Two studies investigating the CV, one in a population-based cohort and the other among patients with hypertension, did not find an association with WMH volume or SVD, whereas onecross-sectional study of relatively healthy participants did report that increasedsystolic CV was related to more SVD. Diastolic BPV was assessed in only one cross-sectional study , in which it was unrelated to the presence of SVD in patients with hypertension. The differences with our results may be explained by differences in studypopulations. The abovementioned studies often excluded patients with a history ofstroke,31 cognitive impairment,30 a significant stenosis of theinternal carotid artery,30 or severe heart disease.31 Taken together, BPV seems toplay a role in the prevalence and progression of WMH, but depending on thepopulation  andthe type of BPV index used, this role may be larger or smaller.Besides ARV, we did not observe associations of any other index of BPV  with WMH volume at baseline or follow-up. By contrast, two previouscross-sectional studies did find that patients with increased 24-hour systolic SDhad a higher burden of SVD. the resilience of ARV to confounding by nocturnal blood pressure dips is animportant advantage of using this metric when assessing 24-hour BPV. When using SD, CV, or VIM, information bias due to admixture of nocturnaldipping patterns in 24-hour variability may attenuate associations to the null. Ahead-to-head comparison of the most commonly used BPV indices in the same studypopulation can help to disentangle the properties of the different indices. As such,our findings support the routine use of the ARV for assessing 24-hour BPV.The heterogeneity in findings between studies could in part be explained by thedifferent BPV indices used. Although the optimal measure remains to be determined, However, in the meta-analysis, this difference was not observed in studiesthat accounted for potential confounders like age, sex, and traditionalcardiovascular risk factors. So far, only one study has reported on the association between nocturnaldipping and WMH volume longitudinally. This population-based cohort of Chinese participants without cardiovasculardisease, reported that the absence of a nocturnal blood pressure dip was associatedwith a significantly larger increase in WMH volume during five years of follow-up. Although, we did not replicate this last finding, administering bloodpressure lowering medication at bedtime rather than in the morning, the so calledchronotherapy, has been shown to restore the natural circadian rhythm of bloodpressure and also to reduce the risk of cardiovascular events, including stroke, inthe Hygia Chronotherapy Trial, but not in the more recent TIME study. It is currently unknown if chronotherapy reduces the risk of SVD.Regarding nocturnal dipping, our results are in line with a prior meta-analysis offive cross-sectional studies that showed participants with less nocturnal dippinghad a higher WMH volume at baseline. Impaired blood pressure regulation can be a consequence of reducedsympathetic drive due to brain injury, but BPV could also contribute to WMH throughdirect reduction in cerebral perfusion.19 Under normal physiologicalcircumstances, arterial elasticity and compliance help to maintain continuous organperfusion by dampening fluctuations in blood pressure (i.e. the Windkessel effect). When arterial compliance is reduced with arteriosclerosis, this may lead toimpaired organ perfusion with higher BPV. On the basis of the Windkessel effect, wepostulate that changes in perfusion may occur in particular with fluctuations indiastolic rather than systolic blood pressure, which may prompt closer attention fordiastolic BPV in future studies. The observed effect modification by baselinecerebral perfusion in our study supports the notion that low perfusion could renderparticipants more vulnerable to large fluctuations in BPV, while participants withrelatively high cerebral perfusion may be more resilient. The lack of mediation bycerebral perfusion in our study was due, at least in part, to the absence of anassociation between baseline cerebral perfusion and WMH. As various prior studiesdid observe lower cerebral perfusion in individuals with more severe WMH burden, potential mediation effects by perfusion warrant further assessment in othercohorts. Simultaneous measurement of carotid pulse-wave velocity, intracranialpulsatility, pulse pressure, and cerebrovascular reactivity in such studies may aidto understanding the association between BPV and WMH.Twenty-four hour BPV reflects the central sympathetic drive, autoregulatorymechanisms, and arterial compliance.A strength of this study is the longitudinal design, which enabled us to examine WMHprogression and shed more light on the role of cerebral perfusion. There are alsolimitations that should be taken into account. First, the number of participants wasrelatively small, which hampers precision. Attrition over time may have led - mostlikely - to an underestimation of true effect estimates due to selection. Second,although we adjusted our analysis for the most important confounders, we could notaccount for all potential confounding factors. Third, heterogeneity of the studypopulation may hinder interpretability, even though associations were generallysimilar across participant groups. Fourth, longer follow-up beyond two years isneeded to entirely rule out reverse causation. Fifth, a single resting-statemeasurement of cerebral perfusion is unlikely to fully capture the variability incerebral perfusion that may be expected to accompany the variability in bloodpressure during the day and night. Sixth, BPV is influenced by blood pressurelowering medication, which was continued during 24-hour ABPM. Lastly, 24-hour ABPMwas not repeated at follow-up, so we cannot be certain that the BPV observed atbaseline persisted for two years.In conclusion, diastolic nocturnal dipping was associated with WMH volume, and24-hour diastolic ARV with progression of WMH volume over time, most profound inparticipants with low cerebral perfusion at baseline. Whilst requiring replication,these findings suggest that blood pressure patterns and variability may be a targetfor prevention of SVD.Click here for additional data file.Supplemental material, sj-pdf-1-jcb-10.1177_0271678X221149937 for Twenty-fourhour blood pressure variability and the prevalence and the progression ofcerebral white matter hyperintensities by Naomi LP Starmans, Frank J Wolters,Annebet E Leeuwis, Esther E Bron, Hans-Peter Brunner La Rocca, Julie Staals,Geert Jan Biessels, L Jaap Kappelle and for the Heart-Brain ConnectionConsortium in Journal of Cerebral Blood Flow & Metabolism


The UK kidney offering scheme introduced a kidney donor risk index (UK-KDRI) to improve the utility of deceased-donor kidney allocations. The UK-KDRI was derived using adult donor and recipient data. We assessed this in a paediatric cohort from the UK transplant registry.We performed Cox survival analysis on first kidney-only deceased brain-dead transplants in paediatric (<18 years) recipients from 2000-2014. The primary outcome was death-censored allograft survival >30 days post-transplant. The main study variable was UK-KDRI derived from seven donor risk-factors, categorised into four groups . Follow-up ended on 31-December-2021.319/908 patients experienced transplant loss with rejection as the main cause (55%). The majority of paediatric patients received donors from D1 donors (64%). There was an increase in D2-4 donors during the study period, whilst the level of HLA mismatching improved. The KDRI was not associated with allograft failure. In multi-variate analysis, increasing recipient age , recipient minority ethnic group , donor height  and level of HLA mismatch  were associated with worse outcomes. Patients with Level 1 and 2 HLA mismatches (0 DR +0/1 B mismatch) had median graft survival >17 years regardless of UK-KDRI groups. Increasing donor age was marginally associated with worse allograft survival .Adult donor risk scores were not associated with long-term allograft survival in paediatric patients. The level of HLA mismatch had the most profound effect on survival. Risk models based on adult data alone may not have the same validity for paediatric patients and therefore all age-groups should be included in future risk prediction models. Children and young adults with end-stage kidney disease (ESKD) require transplants which last their lifetime , 2. YounIn order to improve deceased donor transplant survival, national kidney allocation policies have developed strategies for matching donors to recipients, broadly based on kidney donor ‘quality’ factors and donor-recipient human leucocyte antigen (HLA) mismatching –8. In thThe UK-KDRI is currently used to allocate a subset of points in the kidney offering scheme . The UK-en-bloc kidneys and re-transplants. Cause of allograft failure was categorised using the primary cause reported to NHSBT, which of note, does not differentiate between rejection subtypes.Data were obtained from the UK Transplant Registry, held by NHS Blood and Transplant (NHSBT). NHSBT mandates collection of transplant activity and outcomes. The dataset was de-identified by NHSBT prior to use for research. All first DBD kidney only transplants in paediatric recipients (<18 years of age) performed between 2000-2014 (inclusive) were included. This study period was chosen to represent contemporaneous management and enable long-term follow-up. Some donor variables were also less complete pre-2000. Last follow-up was taken on 31 December 2021. Transplants from donors following circulatory death  were excluded as their usage was not uniform during the earlier years , Level 3 - 0 DR + 2B mismatch OR 1 DR + 0/1 B mismatch, Level 4 - 1 DR + 2 B mismatch OR 2 DR mismatch (least favourable)  is calculated using the Modification of Diet in Renal Disease (MDRD) Study equation:KDRI scores are split according to the quartiles defined in the kidney allocation scheme - D1 ≤ 0.79, D2 0.79 – 1.12, D3 1.12 – 1.50, D4 ≥1.50 .In addition, we performed analysis based on the simplified, five-variable, UK Watson KDRI formula :Acute kidney injury (AKI) was classified using Kidney Disease Improving Global Outcomes (KDIGO) criteria using the donor terminal creatinine and urine output in the last hour and average urine output per hour in the last 24 hours.Data missingness: Data was complete across all variables in 60% of cases. Data for delayed graft function was unknown for 25% of cases and not analysed. Data missingness for donor factors were low (1-6.5%) [Survival analysis: The primary outcome was death censored graft survival. The primary exposure variable was the UK-KDRI risk group. UK-KDRI and Watson formula were also analysed as continuous scores. Of note, there were only eight patients using the Watson high risk threshold ≥1.35 . We furtBetween 2000-2014, 1728 primary kidney only transplants were performed in paediatric recipients (<18 years of age), of which 950 were from DBD transplants. Patient survival at 5, 10 and 15 years post-transplant was 98.3%, 96.0% and 93.7% respectively. Graft survival at 5, 10 and 15 years was 82.3%, 67.5% and 58.6% respectively. Forty-two patients had graft failure in the first 30 days post-transplant, mainly due to graft thrombosis, and were excluded from further analysis, leaving 908 patients. Characteristics of included patients are presented in 2) versus D2-D4 . As the study focused on donation following brain death, the main cause of death was intracranial haemorrhage and cardiovascular disease. In the D1 group, there was a higher proportion of donor death due to trauma. The level of HLA mismatching was better in transplants from D2-D4 donors with 10-12% transplants being Level 3-4 mismatches versus 31% of transplants from D1 donors. Though most patients received transplants from donors in the D1 group , a significant proportion of donors were transplanted from higher donor risk groups .The characteristics of deceased donors are presented in The 2006 change in the UK Kidney Offering Scheme introduced prioritisation of paediatric recipients for favourable HLA matched donors and resulted in an increase of ‘well-matched’, Level 1 and 2 mismatched kidneys [The KDRI score was not associated with allograft loss, either as a continuous score or using the categorical D1-D4 risk groups [Recipient factors associated with worse graft survival were higher recipient age, minority ethnic groups, patients on dialysis at the time of transplant and higher level of HLA mismatching. The risk associated with age was non-linear; older recipients had an increased risk of transplant failure compared to younger recipients . Recipients of ethnic minorities had a 29% increased risk and patients who were not pre-emptively transplanted had a 38% higher risk of graft loss. Patients who had Level 3 and 4 HLA mismatches were 1.9x and 2.4x more at risk of graft loss, compared to the Level 1 mismatch group respectively Figure 3There were no differences in the donor characteristics for the patients who had graft failure in the first 30 days post-transplant Table S2As kidney allocation systems incorporate donor risk indices into allocation policies, it is important to assess whether the scores are applicable to all subgroups of patients including paediatric recipients. We applied the UK-KDRI to a historical cohort of paediatric DBD kidney recipients from 2000-2014 and demonstrated that the usage of higher risk donors (D2-D4) increased whilst the level of HLA mismatching improved over time. The UK-KDRI did not predict death-censored allograft survival, whilst Level 3 and 4 HLA mismatches were associated with double the risk of graft failure compared to patient with Level 1 mismatches. Allocation schemes for paediatric kidney transplantation, therefore, need to balance both donor factors as well as HLA mismatching to better promote long-term allograft survival.The UK-KDRI was originally derived from analysis of allograft failure in 7628 first adult kidney only donors and recipients with follow up of 5 years . ResultsWhilst the UK-KDRI allocates a subset of points in the UK Kidney Offering Scheme, the actual acceptance of individual kidneys is decided by local clinical team members. The historical decline rate of offers to paediatric recipients has been steady between 36-48% between 2011-2022, and is comparable to the decline rate for adult recipients (average 50% for standard criteria donors) . 82% of Many factors are considered when accepting kidney donor offers and the decision to decline has to be weighed against the risks of continuing/commencing dialysis , 22. WhiThe effect of donor age was marginal in our study compared to results from studies in adult recipients . NonetheWhilst our study did not show a statistical significance for donor quality variables, higher levels of HLA mismatch were clinically and statistically significant for higher risk of transplant failure. The main cause of transplant failure was also reported to be due to ‘rejection’. It is tempting to speculate that once a certain threshold of functioning donor nephron mass is achieved, chronic alloimmune injury from HLA mismatches becomes the main driver of transplant failure , 35. WhiThe main strength of our study is the completeness of data and long-term follow-up through to adult care made possible by NHSBT. Post-transplant management of this cohort will likely reflect UK practices, which may reduce generalisability to other populations. Results should be interpreted within the limits of the donor and recipient population and not extrapolated to very high-risk donors which were not well-represented. Other limitations are inherent in the statistical models utilised. Cox-proportional hazards models assume that variables are independent, and therefore interactions between donor factors are not implicit in the model. Latent variables not recorded as donor factors are also not considered.Overall, kidney allocation schemes face a balancing act of matching longevity of the allografts to the expected gain in quality life years in the recipient, whilst not prejudicing against any specific patient groups , 12. AltThe original contributions presented in the study are included in the article/Ethical review and approval was not required for the study on human participants in accordance with the local legislation and institutional requirements. Written informed consent from the participants’ legal guardian/next of kin was not required to participate in this study in accordance with the national legislation and the institutional requirements.JK, RC, SM, JD and AW contributed to conception and design of the study. JK performed the statistical analysis. JK wrote the first draft of the manuscript. JK, RC, BR, SM, VK and JD wrote sections of the manuscript. All authors contributed to the article and approved the submitted version.


Hypertension care cascade in resource-limited settings is compromised with a majority of patients with hypertension remaining undiagnosed, untreated, non-adherent, and poorly controlled at every stage. However, there is paucity of information on care and management of hypertensive patients in community-based settings of low-income urban neighbourhoods in India.This was a community-based cross-sectional study conducted in an urban resettlement colony and slum area in the Northeast District of Delhi. The adult population was screened for hypertension using standardized methods, and adherence to medications was assessed using the Morisky Green Levine scale. Binary logistic regression analysis was conducted to ascertain the sociodemographic predictors of the outcome . A p-value < 0.05 was considered statistically significant.We included 8850 adult participants including 5295 females and 3555 males in this study. Nearly 29% of the participants were hypertensive, of which 61.77% were newly diagnosed cases. Furthermore, nearly 81% of the previously diagnosed cases had been initiated on antihypertensive medication, of which 57.54% were adherent to their medications while 36.12% attained controlled blood pressure levels. The odds of having hypertension were significantly higher among males , age ≥ 60 years , high waist circumference  and Body Mass Index of ≥ 25.00 . Furthermore, on adjusted analysis, patients of hypertension having diabetes (DM) comorbidity had significantly higher odds of being adherent to anti-hypertensive medications  compared to those without DM comorbidity, while tobacco users had significantly lower odds of being adherent to antihypertensive medication .Hypertension care cascade in urban slum-resettlement colony setting revealed a high burden of undiagnosed hypertension, low rates of medication adherence, and poor blood pressure control. Strengthening community screening and primary care continuum of care is necessary to improve the hypertension care cascade from early diagnosis to effective management with optimal health outcomes to reduce patient complications and increase longevity. Hypertension (HTN) signifying elevated blood pressure is an established risk factor for cardiovascular diseases and renal dysfunction resulting in premature and preventable mortality , 2. GlobTo meet the sustainable objective goals for a one-third reduction in premature mortality from NCDs by 2030, the global NCD action plan target of a 25% relative reduction in the prevalence of high blood pressure in adults by 2025 is required , 8. HypeWithin India, evidence from the fifth series of the National Family Health Survey NFHS-5, 2019-21), a nationally representative survey in the 15–49 age-group, concluded that only 4 in 10 patients diagnosed with hypertension in India were initiated on anti-hypertensive treatment, while only 3 in 4 on treatment attained optimal blood pressure control . Among t19-21, a Slums are areas of substandard housing and squalor which as per the WHO usually lacks basic amenities such as improved water and sanitation, with insufficiency of living area, non-durable housing, and no secure tenure, with nearly 130 million people in South Asia, including 49% of the total urban population in India living in slums due to unplanned urbanization and large scale rural to urban migration –24. UrbaIn India, extensive screening of hypertension among adults through opportunistic screening in health facilities and community-based screening through frontline workers has been recommended by the National Programme for Prevention & Control of Non-Communicable Diseases (NPNCD) . AlthougThe objective of this study was to assess the hypertension care cascade and their predictors in populations living in urban slums and resettlement colonies in Delhi i.e., proportion of population with hypertension, proportion of hypertension patients initiated on antihypertensive treatment, proportion of hypertensive patients initiated on treatment that were adherent to treatment, and the proportion of patients on treatment that had controlled blood pressure levels.Design and Setting: This was a community-based cross-sectional study conducted in an urban resettlement colony and slum area in the Northeast District of Delhi having an estimated ~ 54,614 total population, a site purposively selected, as it represents the field practice area of a government medical college. The study area included Gokalpuri urban resettlement colony , Sanjay Colony urban slum (~ 4467), Gokalpuri village (~ 8608), and the adjoining Ganga Vihar urban resettlement colony . A Demographic Developmental and Environmental Surveillance Site (DDESS) was recently established in in the area inclusive of complete Geographic Information System (GIS) based mapping of the sociodemographic correlates of the study population. The household level response rate of the current survey was ~ 97% due to high levels of pre-existing community engagement .Study Population: This study included all individuals aged ≥ 18 years who were residents of the area for at least 6 months irrespective of their medical history. Data were collected for a period of 2 months from March-April 2023.Primary Outcome of the study was the detection of Hypertension (including both newly diagnosed or previously diagnosed cases). Hypertension was defined on screening as either a systolic blood pressure (SBP) ≥ 140 mm Hg or diastolic blood pressure (DBP) ≥ 90 mm Hg, or any individual who self-reported themselves as previously diagnosed patients of hypertension.Secondary outcomes were the proportion of hypertensive patients initiated on treatment, proportion of patients initiated on antihypertensive medications that were adherent to their prescribed treatment, and the proportion who had controlled blood pressure values.Operational definitions: Those participants who self-reported having hypertension diagnosed by any healthcare provider or currently taking any antihypertensive medication were recorded as ‘previously diagnosed hypertensive’. Newly diagnosed hypertensives were those detected with either SBP ≥ 140 or DBP ≥ 90 upon screening without past history or diagnosis of hypertension. Controlled blood pressure was considered as previously diagnosed hypertensive patients with SBP and DBP less than 140 and 90 mm of Hg, respectively .Adherence to antihypertensive medications was assessed using the previously validated four-item Morisky Green Levine (MGL) adherence scale . The MGLSample Size and Sampling Strategy: The sample size was adequate at 95% confidence levels, 3% absolute precision, design effect of 3.5 considering the heterogeneity in the slum and expecting 50% expected prevalence of adherence to antihypertensive medication . The entMethodology: Face to face interviews with respondents in the households were conducted with the participants by a total of ten trained field investigators in the local language, Hindi, using a pretested structured questionnaire. Electronic data collection using EpiCollect android application was conducted which has features of both online and offline data collection and data validation with facility for real-time monitoring . Weight Supervision of the field investigators and quality assurance with random verification in 5% of the households was conducted by the field supervisor and the project coordinator while data quality was maintained through regular assessment and feedback provided by the project data manager.Blood pressure (BP) measurement: The BP in all participants was measured as per standard guidelines  by the tThe following independent variables were considered in the analysis based on association with the study outcomes observed in previous studies –16, 29.Age of the participants was stratified into young (18–39), middle (40–59), and older adults (≥ 60 years), gender : education . The income level of the respondents was categorized as those with a monthly household income of median and below  and above median  value of the study sample.Those who reported currently using tobacco in any form (either smoking or smokeless) were categorized as tobacco users.Alcohol intake was measured using a single close ended item “Do you consume Alcohol” with options, “Never consume”, “Consume daily”, and “Consume occasionally”. The participants reporting consumption of alcohol either daily or occasionally were classified as “Yes”, or else as “No”.Participants with absence of regular exercise  or in occupations not involving vigorously intensive activities were considered as having sedentary lifestyle, while those involved in regular exercise or involved in occupations involving vigorously intensive activities were considered as not having a sedentary lifestyle.Family history of Hypertension was categorized as Yes (if one or both parents were previously diagnosed as having hypertension) and No (if none of the parents of the participant had been diagnosed as having hypertension).Body mass index (BMI) was categorized using the Pan Asian classification: underweight (BMI < 18.5), normal (BMI: 18.5–22.9), overweight (BMI: 23.0–24.9), and obese (BMI ≥ 25.0) .Waist circumference was measured for each participant and categorized as Low , Moderate  and High  .The dataset was cleaned using MS-Excel 365. Descriptive statistics were performed to show the distribution of variables and provide summary statistics. Bivariate analysis was conducted by testing for association of the outcomes  with the independent variables using chi-square for categorical and independent samples t-test for continuous variables. Furthermore, a binary logistic regression was performed to ascertain independent association with outcome variables. The variables which on test for association had a P-value of < 0.20 in the bivariate analysis were entered into the multivariable analysis. Since education levels have been found to be associated with hypertension in most previous studies, it was included into multivariate model despite having a P-value > 0.20 in the unadjusted analysis. Both unadjusted odds ratio and adjusted odds ratio (AOR) with 95% CI were reported. For the final model, 5% was considered as the statistical significance level. Additionally, a multivariable linear regression was performed to check for associations of sociodemographic and lifestyle variables with systolic and diastolic blood pressure readings of the participants, wherein unadjusted and adjusted B-coefficients with 95% CI were reported. Model assumptions for both regression analysis such as multicollinearity, outliers and goodness of fit of each model was checked. All analysis were performed using Stata .The study was approved by the Institutional Ethics Committee. All participants provided written and informed consent. Patients detected with Hypertension on screening with either suboptimal medication adherence or lack of initiation on treatment were briefly counselled on health risks of uncontrolled hypertension, and referred to their nearby local government health facilities for further evaluation and management.The present study screened 8850 adult participants for hypertension including 5295 females and 3555 males. The household response rate of the survey was ~ 97%. Table The prevalence of hypertension in the sample was 28.64%  including 969 (10.95%) previously diagnosed and 1566 (17.69%) newly diagnosed cases , 180  patients were not on treatment i.e., not taking any antihypertensive medication to lower blood pressure, while among those taking antihypertensive medications (n = 789), only 454  were adherent to their prescribed blood pressure lowering drugs. On adjusted analysis, patients of hypertension having DM comorbidity had significantly higher odds of being adherent to anti-hypertensive medications  compared to those without DM comorbidity, while tobacco users had significantly lower odds of being adherent to antihypertensive medication  (Table Among previously diagnosed hypertensive patients taking antihypertensive medications (n = 789), only 285  patients achieved controlled blood pressure levels. On adjusted analysis, patients with higher BMI  had significantly lower odds of achieving blood pressure control. Furthermore, patients initiated and adhering to antihypertensive medications had nearly 1.5 times higher odds of attaining controlled blood pressure levels . Overall, 362  participants had controlled blood pressure among the previously diagnosed HTN cases (N = 969)  is higher than the burden observed in a study conducted in an urban slum of Mumbai (23.6%)  and alsoAdvancing age and alcohol consumption were found to be positively associated with the odds of having hypertension, a finding corroborated from previous evidence . The preNearly one in five participants had undiagnosed hypertension in the present study, a finding which indicates the need for intensification of screening, both opportunistic and community-based in resource limited settings. Furthermore, male gender and increasing age were associated with undiagnosed hypertension in this study, findings consistent with a single site study conducted in Puducherry, a town in Southern India . MoreoveIn this study we observed nearly one in five previously diagnosed hypertensive cases were not initiated or not taking any anti-hypertensive medications signifying major deficiencies in the continuum of care as these patients possibly did not report back to their health system, a finding also observed in a study in slums in Bangladesh . FurtherCurrent tobacco users in previously diagnosed hypertension cases in this study was 113 (11.66%), a finding lower than that observed in cross-sectional studies from slums in Bangladesh (27.33%) , KolkataThe study has several strengths including a large sample size ensuring validity of the data, while representativeness was high when considering the problem in urban slum settings. Furthermore, all components of a disease care cascade including medication adherence, an information which is not usually collected in nationally representative secondary surveys were incorporated in this study. However, there are certain limitations to this study. Firstly, the findings of the present study should not be generalized to people living in improved non-slum conditions although we were able to compare the hypertension burden and care cascade outcomes in the present study with estimates derived from multiple large nationally representative datasets. Second, being cross-sectional in nature, the study could not establish causality due to lack of temporal evidence between hypertension and its determinants. Third, some selection bias is possible as those adults who were not available in the household during the survey period were omitted. Similarly. Recall bias could have contributed to overestimation of previously diagnosed cases of hypertension, while social desirability bias may have contributed to inflated measures of antihypertensive medication adherence. Fourth, we did not ascertain adherence to prescribed healthy diet such as salt restriction and consumption of fresh fruits and vegetables in the participants which can influence blood pressure control . Fourth,Our study has some important implications for enhancing the hypertension care and control cascade in slum settings in India and similar low-resource settings in LMICs. First, despite the mandate for annual community-based population screening for hypertension by frontline health workers (FHWs), a large proportion of existing patients with hypertension in slum residing communities remain undiagnosed signifying gaps and inefficient screening . RefreshIn conclusion, hypertension care cascade in urban slum-resettlement colony setting revealed a high burden of undiagnosed hypertension, low rates of medication adherence, and poor blood pressure control. Strengthening community screening and primary care continuum of care is necessary to improve the hypertension care cascade from early diagnosis to effective management with optimal health outcomes to reduce patient complications and increase longevity. Future research should ascertain the individual, community, and health-system factors responsible for missed or delayed screening, diagnosis, and initiation of antihypertensive treatment in urban slum areas.


In HypAll, all markers of oxidative stress except malondialdehyde were increased compared to the controls. After adjustment for age, this association was maintained for the protein stress markers SHp and 3-nitrotyrosine. With regard to the markers for DNA damage, there was no difference between HypAll and the controls. Further, no significant differences became apparent in the levels of both oxidative stress and DNA damage between HypWell and HypPoor. Finally, a positive correlation between the development of blood pressure and oxidative stress was observed in the longitudinal study based on the changes in D-ROM and systolic blood pressure. In conclusion, we found increased oxidative stress in extensively treated hypertensive patients correlating with the level of blood-pressure control but no association with DNA damage.Patients with arterial hypertension have an increased risk of developing tumors, particularly renal cell carcinoma. Arterial hypertension is linked to DNA damage via the generation of oxidative stress, in which an upregulated renin–angiotensin–aldosterone system plays a crucial role. The current study investigated surrogates of oxidative stress and DNA damage in a group of hypertensive patients  and subgroups of well  and poorly  controlled hypertensive patients compared to healthy controls (n = 8). In addition, a longitudinal analysis was performed with some of the hypertensive patients. Markers for oxidative stress in plasma  and urine (8-oxodG, 15-F In 2019, arterial hypertension affected approximately 33% of the global population over the age of 30 ,5,6. ArtOxidative stress describes the state of a system in which oxidants are present in excess compared to antioxidants. This imbalance is the result of increased formation of reactive oxygen species (ROS) and/or reduced antioxidant defense mechanisms . In elevIn rats, we demonstrated that elevation of blood pressure by angiotensin II infusion resulted in an increased mutation frequency in the kidney, likely due to oxidative stress induced by the hormone and subsequent oxidative DNA lesions . In the Patients were recruited via the outpatient consultation for refractory hypertension at the University Hospital of Würzburg (UKW) and via the Myocardial Sodium Content In Cardiac Disease (MyStIC) study . In the The MyStIC study was a clinical study of the German Centre for Heart Failure (DZHI) of the UKW to measure the sodium content in the heart and skeletal muscle. It was an observational study using a sodium MRI to determine differences in sodium storage in three different groups: (1) patients with primary hyperaldosteronism, (2) patients with essential hypertension, and (3) healthy volunteers. The inclusion criteria for the Best-In-Tension Study registry and the inclusion and exclusion criteria of the MyStIC study are listed in Thus, patients with arterial hypertension were recruited from the Best-In-Tension registry and the MyStIC study, whereas healthy volunteers, as a control group, were recruited solely through MyStIC. Of the original 12 healthy volunteers, 2 subjects each  had to be transferred from the control group to the HypWell and HypPoor groups because of detected high blood pressure. Blood samples and urine for further examination of markers of oxidative stress and genomic damage were taken as part of the baseline examination of the patients or subjects; the clinical data obtained for this purpose were obtained from the study database. Approval for the Best-In-Tension Study and the MyStIC Study was granted by the responsible ethics committee of the medical faculty of the University of Würzburg .The data collection of all patients and healthy subjects was carried out equally. Blood and urine parameters were determined by the central laboratory of the University Hospital Würzburg. The physical examination included the determination of body height and weight as well as the measurement of blood pressure on the upper arm using a standard sphygmomanometer. After the patient sat down, the blood-pressure cuff was applied, and 5 min of rest was observed. Three measurements were taken at intervals of 2 min each on the same arm according to the following scheme: 1st measurement in the sitting position, 2nd measurement in the lying position, and 3rd measurement while standing. Ambulatory blood-pressure monitoring was performed either at the DZHI or externally. Information on pre-existing conditions, cardiovascular risk factors, and current medication was obtained from the medical history and previous doctor’s notes. Most laboratory parameters were available from almost all participants, with the exception of some parameters: for example, 21 and 19 complete cases for proteinuria/albuminuria, 15 and 20 for ACE, and 25 and 24 for uric acid were available for HypWell (n = 36) and HypPoor (n = 28), respectively.Peripheral venous blood was collected into a 9 mL EDTA monovette . Blood separation by gradient centrifugation, as described by Schupp et al. , startedg . The sediment was discarded and the urine was aliquoted and stored at −20 °C.The urine samples given by the test persons reached the laboratory in 10 mL monovettes within two hours and were centrifuged at 4 °C for 10 min at 4100× http://rsb.info.nih.gov/ij/ (accessed on 24 June 2015) [Immediately following PBMC isolation, 20,000 cells each were applied to precleaned slides using cytocentrifugation . The cells were fixed in ice-cold methanol for at least 24 h, washed with PBS, blocked with 5% donkey serum , 1% BSA, and 0.3% Triton X-100 in PBS for 30 min, and then incubated 1 h at 37 °C with anti-gamma H2A.X (phospho S139) antibody (EP854(2)Y, ab81299, Abcam, Cambridge, UK) at a dilution of 1:100 in a blocking solution. After extensive washing with PBS containing 0.2% Tween, they were incubated for 30 min at 37 °C in the dark with a fluorescein isothiocyanate-conjugated secondary antibody (CF488A Donkey Antirabbit IgG (H + L), #20015, Biotium, Hayward, CA, USA). Nuclei were counterstained with DAPI, and the slides were mounted with Confocal Matrix . Images were captured using a Nikon Eclipse 55i fluorescence microscope  at a 400-fold magnification. Quantification was done by counting γ-H2AX foci in 50 cells per individuum with ImageJ 1.47 v . To stimulate mitosis of predominantly lymphocytes, 10 µg/mL phytohaemagglutinin was added. The cell culture flasks were then incubated standing at 37 °C and 5% CO2 for 24 h in an incubator . The cells were centrifuged on pre-cleaned slides in ice-cold methanol. Staining was performed with the nucleic acid stain GelGreen  before mounting the slides with DABCO; 2000 cells with single-segmented, round to oval nuclei (characteristics of lymphocytes) per individuum were evaluated on the day of staining and after blinding, at a 400× magnification on the Eclipse 55i microscope . On the one hand, the proportion of double-nucleated and multinucleated (≥3 nuclei) cells, as well as apoptoses and mitoses, in 2000 single-nucleated cells (EC) were counted and, on the other hand, nuclear abnormalities such as MN, nuclear buds, nuclear blebs, and NPBs were recorded. The latter three are shown combined as “nuclear anomalies (NA)”. The evaluation criteria were based on those of Fenech [Immediately after isolation of the PBMC, 5 mL of the leucocyte suspension containing approximately 1 million cells/mL was transferred into a 25 cmf Fenech . DeviatiThe plasma samples were used to detect three different markers for oxidative and nitrosative stress, respectively.2O2/100 mL plasma [The derivatives of reactive oxygen metabolites (D-ROM) test was used as a biomarker for oxidative stress. Since ROS have a very short half-life , the morL plasma .The assay for thiol groups in proteins (SHp) is a photometric method for the determination of the thiol concentration in plasma and was performed at the Centre for Health Protection, National Institute for Public Health and the Environment, Bilthoven, The Netherlands, using the SHp test  as described in Jansen et al. .As a marker of nitrosative stress, 3-nitrotyrosine in plasma was measured with the Nitrotyrosine ELISA Kit  according to the protocol provided by the manufacturer.Three different markers of oxidative stress were detected in spontaneous urine, and each was related to creatinine concentration.2t-isoprostane was measured using the “Urinary Isoprostane EIA Kit (EA-85)” . The results were expressed in ng 15-F2t-IsoP/mg creatinine after normalization with creatinine values. Malondialdehyde was measured using the “QuantiChromTM TBARS Assay Kit (DTBA-100)” . For TBARS values > 1.5 µM, the sample was diluted, the assay was performed again, and the result was multiplied by the dilution factor. The results were expressed in relation to creatinine as µmol MDA/mol creatinine. 8-oxodG was quantified with the “DNA Damage (8-OHdG) ELISA Kit (#SKT-120)” . The results were related to urine creatinine and expressed in ng 8-oxodG/mg creatinine. Creatinine in urine was determined with the “Creatinine (urinary) Colorimetric Assay Kit (Item No. 500701)” .15-FMetric variables were expressed as median with associated 1st and 3rd quartiles (Q1-Q3) calculated with Tukey pivots, and categorical variables as count with percentages. Since most variables were non-normally distributed (Shapiro–Wilk test), differences and correlations were calculated using nonparametric test procedures.Group comparisons were done by the Mann–Whitney U test or Wilcoxon signed-rank test and Kruskal–Wallis or Friedman’s test, as appropriate. After applying the Kruskal–Wallis or Friedman’s test, post hoc tests were carried out using Bonferroni correction. Correlations between metric variables were indicated with the rank correlation coefficient according to Spearman (r). Based on Cohen’s classification , this meIn addition, covariance (ANCOVA) and regression analyses were carried out for further consideration of group differences and correlations. In order to fulfill the requirements for these parametric methods, it was necessary to log-normalize non-normally distributed variables. The variables transformed with the decadic logarithm were given the prefix “lg”.Regression analyses were carried out to determine correlations between several explanatory (independent) variables and a dependent variable. The model equation of the multiple linear regression model is:Each dependent variable y  was assigned the independent variable x  which had shown significance in the simple correlation analyses performed previously. The influence of the independent variables is expressed by the standardized coefficient β. The nonstandardized regression coefficient B allows a statement on the quantitative change of y if x changes by one unit. ε corresponds to the residual. The coefficient of determination R2 indicates what percentage of the dependent variable can be explained by the regression coefficients of the model estimation. In the corrected R2, the R2 is adjusted for the number of cases (n) and the number of independent variables.p > 0.1) from the model until only those variables remained that made a significant contribution to the explanation of variance. The following dependent variables were assessed: age, sex, BMI, diabetes, sleep apnea, mean systolic blood pressure, renin, eGFR, serum protein, cholesterol, and NT-pro-BNP. The prerequisites for the application of a multiple linear regression model were checked in each case.In this paper, the regression analyses were conducted in an exploratory approach using the backward selection method. The statistical program excluded the independent variable with the highest insignificance  and GraphPad Prism version 6  were used for statistical evaluation.For all statistical procedures, a The study participants were divided into three groups according to their intake of antihypertensive drugs and their average systolic blood-pressure values in the ABPM or their practice blood-pressure values see . For thiOf the total 72 study participants recruited, 8 could be assigned to the control group and 64 to the hypertensive group, with 36 patients showing well-controlled blood pressure and 28 patients showing poorly controlled blood pressure .In the 24 h urine collection, patients in the HypPoor group more often exhibited proteinuria and albuminuria than the controls and the HypWell individuals. There were no significant group differences in the RAAS parameters. The controls had significantly higher cholesterol levels compared to the hypertensives; only one of them was taking a statin. Other metabolic parameters were similar across groups. As a marker of heart failure, NT-proBNP was significantly higher in the HypPoor and HypAll compared to the controls.According to the group classification, there were significant differences in the use of antihypertensives between the controls and the hypertensive groups . Patient2t-IsoP) but also a marker of antioxidative capacity (SHp) in both the urine and blood plasma of the study participants. 2t-IsoP. Two other markers of oxidative stress, D-ROM, and 8-oxodG, showed a tendency to increase, whereas MDA did not change. After correcting the group differences for age, this significant difference remained for SHp and 3-nitrotyrosine, with age still showing a significant influence on SHp. For 15-F2t-IsoP, the group difference was no longer significant due to the influence of age .A correlation analysis was performed with the markers for oxidative stress and DNA damage using the clinical parameters collected at the first visit. No correlations with the blood-pressure values were found, except for an inverse correlation between D-ROM and total systolic blood pressure in the ABPM . The markers for DNA damage showed no correlations among each other. The only correlation between oxidative stress markers and DNA damage was seen between 3-nitrotyrosine and nuclear anomalies, which was surprisingly negative .Among the oxidative stress markers themselves, only SHp correlated significantly with 3-nitrotyrosine . Patients with sleep apnea had less SHp. In the backward regression analysis of 3-nitrotyrosine, age, eGFR, and sleep apnea were included as significant influencing factors in the model, whereby patients with sleep apnea had more 3-nitrotyrosine. Age emerged as the only significant influencing factor for 15-F2t-isoprostane  and the first follow-up (Fup1) was 7 ± 2 months (16 patients) and between V1 and the second follow-up (Fup2) 14 ± 2 months (11 patients). The range of clinical parameters collected for Fup1 and Fup2 was the same as for V1 see . The difp ≤ 0.05), accompanied by a similar reduction in ABPM  or poorly (HypPoor) controlled blood pressure showed increased systemic oxidative stress but no increased DNA damage compared to healthy individuals. Six different, established markers of oxidative stress to lipids, DNA, and proteins and three markers of DNA damage were quantified, with all markers except one indicating increased oxidative stress in the group of hypertensive patients, three of them significantly. A key strength of this analysis is that the population studied allowed not only for comparison between healthy controls and hypertensive patients but also according to the level of hypertension control. Further, patients were very well characterized for office and ambulatory blood pressures, relevant comorbidities, biomarkers, and medication. Moreover, we were able to perform longitudinal studies on a subset of the hypertensive patients, allowing for the investigation of changes in BP and oxidative markers over 14 months. A major limitation of this study is that, compared with the number of hypertensive patients (n = 64), only a very small and younger control group (n = 8) with normal blood-pressure values could be identified for this analysis; therefore, we also performed age-adjusted and regression analyses of oxidative stress markers.2t-isoprostane and MDA, were measured in urine. 15-F2t-isoprostane was significantly elevated in the hypertensive groups, as was reported before in some studies . Adj. Adj2t-is  in proteins, which are an important antioxidant force in redox balance and can be used as biomarkers of redox status, were determined photometrically in plasma samples ,43. Afte3-Nitrotyrosine is a marker of nitrosative stress to proteins, and the marker showing the clearest difference between the controls and hypertensives. Elevated 3-nitrotyrosine levels in hypertensives have also been found by other groups ,55, but The oxidatively altered nucleic base 8-oxodG acts as a link between oxidative stress and DNA damage markers. As recently reviewed, it reflects the global oxidative stress of an organism, is established as the most important marker of oxidative nucleic base modifications, and is predictive for a number of cancer types ,63. ConsThe markers discussed up to this point were examined in serum and urine, respectively, and thus reflect oxidative damage to the entire body or, in urine, primarily to the kidney. No markers of oxidative stress were determined in the blood cells themselves, as these would only represent local effects. DNA damage, on the other hand, which will now be discussed, can accumulate in the long-lived lymphocytes , where iFurthermore, the patient population investigated in this study differed significantly from that of other studies. Since the patients in the HypAll group were patients with resistant hypertension, this study was preceded by many years of taking various antihypertensive drugs. Thus, in addition to the antioxidant effect of antihypertensive drugs, an antigenotoxic effect can be assumed, which may have prevented an increase in markers for DNA damage in the HypAll group. We have demonstrated this ability of inhibitors of the RAAS, in particular of AT1R blockers and mineralocorticoid receptor antagonists, in vitro and in animal studies ,80. ThisIt would, therefore, be very interesting in a future prospective study, preferably with therapy-naïve patients, to investigate the antioxidative and thus possibly also the antigenotoxic effects of different antihypertensive drugs on oxidative stress, with a focus on RAAS blockers. To distinguish between the effects of individual antihypertensives, it would be desirable to include in this study subjects treated with monotherapy. Since the guideline of the European Society of Cardiology/European Society of Hypertension recommends a combination of two preparations already at the initiation of therapy, except in very mild hypertension , it is nIn summary, we found increased levels of oxidative stress in treated hypertensive patients, but no increase in basal DNA damage, including a marker known to predict future cancer risk. This suggests that the oxidative stress associated with hypertension in the current study samples was not sufficient to induce measurable DNA damage, which may be due to the antioxidant potential of antihypertensive medication, especially RAAS blockers. Accumulating evidence from in vitro and in vivo experiments, as well as observations from the present study, suggest that the beneficial effects of these compounds might extend beyond the well-described clinical effects of blood-pressure lowering and renal and cardiac protection, and might also protect against oxidative DNA damage.


Prader-Willi syndrome (PWS) is a rare, complex, genetic disorder characterized by hyperphagia, hypotonia, delayed psychomotor development, low muscle mass and hypothalamic dysfunction. Adults with PWS often have obesity, hypertension and type 2 diabetes mellitus (DM2), known risk factors for cardiovascular disease (CVD) and chronic kidney disease (CKD). Early symptoms of CVD and CKD may be masked by intellectual disability and inability to express physical complaints. Furthermore, kidney diseases are often asymptomatic. Therefore, renal and cardiovascular disease might be missed in patients with PWS. Microalbuminuria is an early sign of microvascular damage in the kidneys and other vascular beds. Therefore, we screened our adult PWS cohort for the presence of elevated urinary albumin and (micro)albuminuria.We retrospectively collected anthropometric measurements, blood pressure, medical history, medication use, urine dipstick and biochemical measurements form electronic patient files. In addition, we performed a systematic literature review on kidney disease in PWS.p=0.027, p=0.019, p<0.001, p<0.001, p=0.011 and respectively).We included 162 adults with genetically confirmed PWS , of whom 44 (27%) had DM2. None had known CVD. All subjects had normal estimated glomerular filtration rate (eGFR) according to non-PWS reference intervals. Elevated urinary albumin or (micro)albuminuria was present in 28 (18%); 19 out of 75 (25%) had an increased urinary albumin-to-creatinine ratio (UACR) and 10 out of 57 (18%) had an increased urinary protein-to-creatinine ratio. Elevated urinary albumin was present at a young age (median age 26 (IQR 24-32) years) and was associated with an significantly higher BMI and LDL-cholesterol levels and higher prevalence of DM2, hypertension and dyslipidemia than those with normal UACR albuminuria, early signs of microvascular disease. All had normal eGFR, according to non-PWS reference intervals, and none had a formal diagnosis of CVD. As muscle mass is low in PWS, creatinine levels and eGFR may be spuriously normal. Urinalysis in this patient group can be used as a screening tool for microvascular (kidney) disease. We propose an algorithm for the detection and management of microvascular disease in adults with PWS. Prader-Willi syndrome (PWS) is a complex, genetic, neurodevelopmental disorder caused by loss of expression of a cluster of paternally expressed genes on chromosome 15q11-13 .During early infancy, PWS is characterized by hypotonia and failure to thrive due to a poor sucking reflex and lethargy , 3, 4. IWith improved healthcare for patients with PWS, life expectancy has increased. As patients with PWS become older, age-related diseases like CVD and CKD become increasingly relevant. Early detection and treatment are crucial to prevent complications, loss of quality of life and early mortality , 25.As symptoms are often atypical, non-specific or even absent –29, the CKD can be diagnosed based on a decreased (estimated) glomerular filtration rate (eGFR) and the presence of (micro)albuminuria . (Micro)Little is known about CKD and CVD in the general population of adults with PWS, as these co-morbidities have only been studied in specific ‘subtypes’ of patients with PWS. In hospitalized patients with PWS, the prevalence of CKD was estimated to be 6.5% . In PWS To fill this knowledge gap, we have systematically screened urine and serum samples for signs of CKD in a cohort of adults with PWS. We also assessed risk factor for CKD and performed a systematic literature review on kidney and urinary tract disease in PWS. Based on our cohort study and systematic review, we provide practical recommendations for the screening and treatment of (micro)albuminuria and CKD in patients with PWS.This international cross-sectional study was performed at the Center for Adults with Complex Rare Genetic Syndromes (CRGS) at the Erasmus University Medical Center, Rotterdam, the Netherlands, the Rare Disease Center of reference ‘Prader-Willi Syndrome and obesity with eating disorders’, in Paris, France and the Division of Auxology in Piancavallo, Italy. Only adults with genetically confirmed PWS who visited the outpatient clinic of one of these reference center between January 2020 and December 2022 were included. Urinalysis was part of a routine systematic health screening in all included PWS patients. Ethical approval and/or individual informed consent was obtained by the Medical Ethics Committee of participating centers according to local rules and regulations.As previously described , the sys2) between 18.5 and 24.9 kg/m2 was considered lean, between 25.0 and 29.9 kg/m2 overweight, 30.0 or more kg/m2 obese and a BMI of 40.0 or more grade III obesity according to the World Health Organization Criteria  to the biochemical and urinalysis. A Body Mass Index  calculation) and lipid profiles ((non-fasting) low density lipoprotein (LDL)-cholesterol, high density (HDL)-cholesterol, triglycerides, total cholesterol), glucose metabolism ) in blood. In random spot urine samples, we measured microalbumin, urinary albumin-to-creatinine ratio (UACR), total protein and/or urinary protein-to-creatinine ratio (UPCR). As the outpatient clinic was in the afternoon in some centers, first morning urine samples were not available. If microalbuminuria was found, the patients were referred to the general practitioner to confirm microalbuminuria in a second urine sample. Second samples were not available for this study. A urine dipstick was used to evaluate the presence of glucose, protein, leukocytes, and nitrite. If urine and blood samples could not be collected on the same day, the blood samples with the shortest time to urinalysis were used. If urine and blood samples were collected more than 12 months apart, the blood sample was excluded from analysis.DM2 was defined as a fasting glucose of 7.0 mmol/L or higher (if available) or a repeated non-fasting glucose above 11.1 mmol/L. As fasting glucose were only available in a few patients, non-fasting glucoses were used in further analysis. Impaired glucose tolerance was tested using an oral glucose tolerance test and diagnosed if measured serum glucoses was between 7.8 to 11.1 mmol/L after two hours according to the American Diabetes Association classification . HbA1c wWe performed a literature search in June 2020 (updated in March 2022) using Embase, Medline, the Web of Science Core Collection, Cochrane Central Register of Controlled Trials and Google Scholar Table S1Screening based on title and abstract was performed independently by three reviewers (either NN and KP or DA and KP). Full-text screening was performed independently by DA and KP. Disagreements were resolved in a meeting with a third reviewer (LG). Data was extracted by DA and NN.p-value of <0.05 was considered statistically significant. To adjust for BMI as possible confounder, a logistic regression analysis was performed.Data was analyzed using IBM SPSS version 28.0. Continuous variables are presented as median [interquartile range (IQR)], dichotomous variables as number and percentage of patients n (%). To investigate the association between microalbuminuria, macroalbuminuria and the presence of risk factors , a Chi-squared test was used for dichotomous variables and a Mann-Whitney U test for continuous variables. A 2 and 60% of subjects had obesity. Grade III obesity was present in 47 of 97 (48.5%) of patients with obesity. Forty-four (27%) patients were diagnosed with DM2 and 17out of 162 (11%) had IGT. Hypertension and hypercholesterolemia were present in 29 (18%) and 23 patients (14%) respectively. In the French cohort, dyslipidemia was present in 37%. None of the patients were diagnosed with cardiovascular events .We included 162 adults with PWS. Baseline characteristics are displayed in 2). Median eGFR (CDK-epi) was 125 [IQR 114-132] mL/min/1.73m2. In males, median creatinine was 61 [IQR 54-69] µmol/L  and eGFR was 127 [IQR 118-135] mL/min/1.73m2. In females, median creatinine levels were 55 [IQR 47-61] µmol/L  and eGFR was 120 [IQR 111-128] mL/min/1.73m2. All patients were classified as CKD stage G1  .In eight Dutch and all French patients, urine samples were present without recent blood samples (i.e. <12 months between urine and blood sample collection). Of the patients with available recent blood samples, all had normal eGFR (CKD-EPI eGFR >90 mL/min/1.73mIQR 118-1 mL/min/1Twenty-eight out of 160 patients (18%) had elevated urine albumin, microalbuminuria or proteinuria Table 2.Urine albumin was elevated in 24 of 157 subjects (15%). The UACR was calculated in 75 patients, as urine creatinine was not systematically assessed in all patients, and was abnormal in 19 of 75 patients (25%), of whom 15 had microalbuminuria and four had macroalbuminuria. UPCR was available for 57 patients, of whom ten (18%) had proteinuria and one nephrotic proteinuria (i.e. 460 mg/mmol).2, p=0.027) and obesity was more prevalent (22 out of 28 (79%) vs 73 of 132 (55%), p=0.023). DM2 and hypertension were more prevalent in those with elevated urine microalbumin or (micro)albuminuria than without . After adjusting for BMI as possible confounder, these variables remained significantly associated with elevated urine microalbumin or (micro)albuminuria (p=0.02 and p=0.013 respectively). Laboratory results on glucose, HbA1c, creatinine, eGFR did not differ significantly between the patients with and without elevated urine microalbumin or (micro)albuminuria. However, LDL cholesterol was significantly higher in those with elevated urine microalbumin or (micro)albuminuria than those without .We did not find any association between elevated urine microalbumin or (micro)albuminuria and age, gender, genotype, GH treatment, alcohol consumption or smoking Table 2.Characteristics, comorbidities, and laboratory results of the Dutch patients with elevated urine microalbumin or UACR are shown in p<0.001).Urine dipstick in the Dutch cohort was positive for leukocytes in 18 of 55 (33%) patients and nitrite in two of 54 (4%). In males, leukocyturia was seen in four of 33 patients . In females, 14 out of 22 (64%) had leukocyturia with 1+ protein in two, 2+ protein in four, 3+ protein in one, 4+ protein in two and amount unknown in five patients. As in the non-PWS population, leukocyturia was more prevalent in females than in males (Urinary glucose was present in three out of 51 (6%) patients, all of whom had DM2 and were already on a treatment regime. Non-fasting (random) blood glucose levels of these patients ranged from 11.9 to 17.4 mmol/L and HbA1c from 62 to 70 mmol/mol, indicating suboptimal glucose management. None of them had proteinuria.). Multiple case reports have been published on patients with PWS and kidney disease. We found eight case reports describing proteinuria (NDN gene which is on the PWS region and ii) NIPA2, a gene not imprinted in patients with PWS that influences magnesium transportation, and that possibly reflects an association between kidney homeostasis or disease and PWS .In patients with PWS and diabetes, three studies reported microalbuminuria (7-56%) or proteinuria (3-11%) –50. In 4Multiple studies have investigated causes of death in PWS. Cohen et al.  describep<0.05). Malformations found included renal hypoplasia, ureteral duplication, bifid renal pelvis, vesicoureteral reflux, pelvicalyceal dilatation and ureteral valves (p=1.00). Sinnema et al.  adults had early signs of microvascular disease, measured by elevated urine microalbumin or (micro)albuminuria, while eGFR was normal. However, as muscle mass is low in PWS (Twenty-eight out of 160 (18%) patients had elevated urine albumin, (micro) albuminuria or proteinuria; eleven of whom were diagnosed with hypertension and sixteen with DM2. No age difference was found between patients with normal and elevated UACR.without DM2 was similar to that in non-PWS patients with long-term DM2. The albuminuria in our PWS patients suggests microvascular damage is already present at a young age (23-33 years).In our literature review, we found an overall prevalence of microalbuminuria of 7-56% and macroalbuminuria of 3-11% in patients with PWS and diabetes –50. We dIn this study, as in the normal population, albuminuria was associated with hypertension, DM2 and obesity. Obesity is associated with chronic kidney disease and glomerulosclerosis. A possible mechanism is hyperfiltration, which leads to albuminuria, regardless of the presence or absence of diabetes –110. FurIn the general population, microalbuminuria is an indicator for microvascular injury, and a risk factor for both CKD and CVD , 53, 54.During the initial visit, the physician should ask about previous UTIs and use of cigarettes and/or alcohol. In case of multiple UTIs, one should consider a kidney ultrasound to detect malformations, assess the post-void residual urine volume and referral to a urologist. In case of substance use, we advise to encourage cessation of smoking or alcohol usage. Furthermore, weight and blood pressure should be measured yearly. In case of hypertension, one should consider analysis to secondary causes such as stress, left ventricle hypertrophy or renal causes and manage both obesity and hypertension according to general guidelines.2 in males and >93 ml/min/1.73m2 in females)  population in both male and female adults with PWS. This finding could be related to low muscle mass, which is decreased by 25 to 37% in patients with PWS , resultifemales)  to avoidfemales) –46. Therfemales) , 113 or females) , 115. Wefemales) Figure 2females) .We advise yearly evaluation of kidney function, glucose levels and lipids. If an impaired renal function is detected, additional investigation using a 24-hour urine and kidney ultrasound should be performed to identify the cause. In addition, a nephrologist could be consulted. A new diagnosis of diabetes or hypercholesterolemia should be managed according to non-PWS guidelines.Urgency symptoms (sudden need to pass urine with or without urine incontinence) and UTIs are common in adults with PWS, according to our literature review and previous study in our cohort  , 119. UTWe recommend performing urinalysis  yearly in all adults with PWS. First morning urine samples are preferred over random urine samples to decrease the influence of orthostatic proteinuria . In thosIn case of abnormalities, a second sample urinalysis should be performed. When microalbuminuria or proteinuria persists, 24-hour urine should be collected to calculate the 24 hour creatinine- and protein excretion. However, in people with of intellectual disability, collecting 24 hour urine might be challenging. In those with normal eGFR but elevated UACR or UPCR without a UTI, an renal ultrasound should be performed.When proteinuria is confirmed, patients should be screened for underlying diseases and any risk factors should be treated. Cardiovascular status should be optimized and cardiovascular risk should be assessed. Referral to (or consultation with) a nephrologist should be considered. Those with progressive proteinuria should be referred to a nephrologist. In adults with PWS with albuminuria and hypertension, an ACE inhibitor or angiotensin-II receptor antagonist should be the first line of treatment due to their renoprotective effects . If obesAs all studies, our study has strengths and limitations. This study is, to our knowledge, the first cohort study to systematically assess kidney function and urinalysis in adults with PWS. However, there are several limitations. Blood and urine samples were not always collected on the same day as the blood samples . As random spot urine samples were collected instead of first morning urine samples, the high prevalence of (micro)albuminuria might partly be caused by sample contamination, orthostatic proteinuria or physical exertion. Furthermore, microalbuminuria was not confirmed in a second sample as repeated samples were only available in four patients. In addition, as muscle mass might be low in patients with PWS, leading to a low serum creatinine, defining microalbuminuria by the UACR or UPCR might have led to an overestimation . SmokingUpon screening, one in every five adults with PWS had elevated urine albumin or (micro)albuminuria which was already present at young age. All had normal eGFR according to non-PWS reference intervals. However, as muscle mass is low in PWS, normal creatinine levels and eGFR may overestimate kidney function in people with this syndrome. As kidney function may be overestimated when only measured by serum creatinine, renal problems may be missed when urinalysis is omitted. Routine screening for microalbuminuria may allow early intervention to avoid CVD and CKD. Health care providers should be aware of the increased risk for CKD and CVD in adults with PWS and should optimize treatment to reduce these risk factors. To prevent long-term complications and impaired quality of life, we provide an algorithm for the screening and management of micro-albuminuria and proteinuria in adults with PWS Figure 2The raw data supporting the conclusions of this article will be made available by the authors on request, without undue reservation.The studies involving human participants were reviewed and approved by Medical Ethics Commission of the Erasmus Medical Center, Rotterdam, the Netherlands. The patients/participants provided their written informed consent to participate in this study. Written informed consent was obtained from the individual(s) for the publication of any potentially identifiable images or data included in this article.Conceptualization, KP, FH and LG. Methodology, KP and LG. Formal analysis, DA. Investigation, DA, NN. Resources, LG. Data curation, DA, NN, GG, CP. Writing—original draft preparation, DA. Writing—review and editing, all authors. Visualization: DA. Supervision, KP, LG and AL. Project administration, DA, KP and LG. All authors contributed to the article and approved the submitted version.