Increased Body Mass Index Is Not a Reliable Marker of Good Nutrition in Hemodialysis Patients

Abstract

Objective. The aim of the study was to assess the body fat (BF) composition in hemodialysis (HD) patients using anthropometry and bioelectrical impedance analysis (BIA) and investigate relationships between BIA-determined BF composition and nutritional parameters in different weight groupings. Design. Cross-sectional study. Setting. A tertiary-care university hospital. Methods. 164 HD patients (M/F: 89/75, mean age: 48.4 ± 15.8 years, mean HD duration: 58.2 ± 42.6 months) were divided into three groups according to body mass index (BMI): normal weight (NW: BMI 18.5–24.9), overweight (OW: BMI 25–29.9), obese (OB, BMI ≥ 30). Biochemical parameters and BF composition using anthropometry and foot-to-foot BIA were compared between three groups. Results. Ninety-six (59%) patients were NW, 40 (24%) were OW, and 28 (17%) were OB. Average mean skinfold thickness (p = 0.005), mid-arm circumference (p = 0.001), BF% (p = 0.001), and fat-free mass (FFM) (p = 0.03) were all significantly greater in the OB group than in the NW group. Compared to the NW patients, the OB group had significantly higher serum levels of glucose (p = 0.03), total cholesterol (p = 0.02), and triglycerides (p = 0.02), but significantly lower serum albumin (p = 0.05) and blood urea nitrogen (p = 0.05). The OB group also had significantly higher white blood cell count (p = 0.002) and serum CRP (p = 0.001) than the NW group. Conclusions. The results suggest that BIA-determined BF composition is correlated with body mass index. In addition, obesity is associated with elevated CRP and white blood cell count and lower serum albumin level in HD patients.