The effect of nutritional status, body composition, inflammation and serum iron on the developement of insulin resistance among patients on long-term hemodialysis.

We investigated the effect of body composition, nutrition, inflammation and iron status on insulin resistance in patients with long-term hemodialysis. We selected 43 stable end-stage chronic renal failure patients, on maintenance hemodialysis. We evaluated the nutritional status, body composition by subjective global assessment (SGA), anthropometric measurements (BMI and waist circumference), bioelectrical impedance analysis and biochemical parameters measurements [serum albumin, cholesterol, HDL-cholesterol, triglyceride, hematocrit, hemoglobin, iron, ferritin, calcium, phosphorus, intact parathormone (i-PTH), TNF-alpha, IL-6 and high sensitivity C-reactive protein]. All parameters were evaluated by comparisons between HOMA-IR tertiles, and after simple regression analysis, by backward multivariate regression analysis we identified independent variables for IR. As the tertile of HOMA-IR increased, serum level of glucose, insulin, and waist increascd, whereas HDL-cholesterol level decreased, or the prevalence of the metabolic syndrome increased across the tertiles of HOMA-IR. After adjustment for gender, age, hemodialysis duration, ferritin, phosphorus, waist and total fat percentages, multivariate regression analysis was performed and the association with HOMA-IR was still strong only for serum levels of iron and TNF-alpha. That explains 16% of the total variation in HOMA-IR. Our results suggest that the increase of IR in end-stage chronic renal failure patients on hemodialysis could be related to anemia and particularly to iron overload. Moreover, chronic inflammatory status with over-production of adipokine TNF-alpha participate in the pathogenesis of IR too. The present study demonstrated that adipokine TNF-alpha and serum iron participated as independent predictors in the pathogenesis of insulin resistance on long-term hemodialysis patients.