The effect of body composition and iron status on insulin resistance in hemodialysis patients
Zorica Rasic, Gordana Perunicic, Jelena Tica, Vesna Popovic, Marina Vujovic & Zoran Gluvic
Background/Aims: High level of inflammatory cytokines was present within malnourished and chronic renal failure maintenance hemodialysis (MHD) patients, but there were conflicting data about the role of inflammation on development of insulin resistance (IR) in non-obese and overweight MHD patients.
Methods: We selected 23 well-nourished and 20 middle- to moderate-malnourished, sex and age-matched, stable MHD patients, 23 male and 20 female, with median dialysis duration of 48 months (IQR 24.582.0). All patients were treated at the Hemodialysis Unit. To determine the nutritional status, body composition and the presence of inflammation of MHD patients we used: subjective global assessment (SGA), anthropometrics measurements (BMI and waist circumference), bioelectrical impedance analysis (BIA) which was performed to quantify body fat and lean body mass, and biochemical parameters measurements [with serum iron, ferritin, intact parathormone (i-PTH), TNF-alpha, IL-6 and high sensitivity C-reactive protein (hs-CRP)]. All parameters were evaluated by comparisons between HOMA-IR tertiles. By backward multivariate regression analysis we identified independent variables for IR.
Results: As the tetiles of HOMA-IR increased, dialysis duration, systolic blood pressure, serum levels of glucose, insulin, and waist circumference increased, whereas HDL-cholesterol level decreased. Serum iron value was increased also. As we expected, the prevalence of the metabolic syndrome were increased significantly across the tertiles of HOMA-IR. HOMA-IR correlated with the levels of iron, ferritin, adipokine TNF-alpha, waist circumference, and total fat percentages. After adjustment for gender, age, hemodialysis duration, ferritin, BMI and total fat percentages, multivariate regression analysis was performed and the association with HOMA-IR was still strong only for serum levels of iron, TNF-alpha and waist circumference. That explains 17% of the total variation in HOMA-IR (Adjusted R2=0.166, P=0.04).
Conclusion: Our study demonstrated that 1) serum iron had participated as independent predictor in the pathogenesis of IR on long-term MHD patients, together with 2) adipokine TNF-alpha and 3) visceral adiposity.