Nutritional and inflammatory status of hemodialysis patients in relation to their body mass index.
OBJECTIVE
The study tested whether obese hemodialysis (HD) patients have a better nutritional and inflammatory state than those with overweight or normal body mass index (BMI).


DESIGN
This was a single-center, cross-sectional study.


SETTING AND PATIENTS
Ninety-six stable HD patients from a local HD unit were divided into 3 groups according to BMI (normal, overweight, and obese).


MAIN OUTCOME MEASURES
Anthropometry, body composition by multifrequency bioelectrical impedance analysis, biochemical nutritional markers, as well as interleukins (IL-1, IL-6, and IL-10), tumor necrosis factor, leptin, and soluble leptin receptor (sOB-R) were measured.


RESULTS
Serum creatinine was significantly elevated in the highest BMI category. Albumin and transferrin were significantly elevated in higher BMI groups after adjustment for age, sex, and diabetes status. The higher BMI group had greater lean body mass (P = .001) and fat mass (P = .0001), higher phase angle (PA), and lower extracellular mass-to-body-cell-mass ratio (ECM/BCM) (P < .05). Inflammatory cytokine levels were not different in the 3 BMI groups. In parallel with increasing BMI, a gradual increase in serum leptin and a trend for decreasing sOB-R were detected (P = .0001 and P = .055, respectively). Both PA (r = 0.295, P = .008) and ECM/BCM (r = -0.345, P = .002) significantly correlated with serum leptin concentration. According to a multiple linear regression analysis, with PA as the dependent variable, age (beta = 0.274, P = .008), creatinine (beta = 0.355, P = .001), and log sOB-R/leptin ratio (beta = -0.465, P = .008) were significant independent predictors of PA.


CONCLUSION
HD patients with elevated BMI demonstrate better nutritional status compared to normal BMI or overweight patients, whereas the severity of inflammation is not related to BMI in HD patients.