Obese sarcopenia in patients with end-stage renal disease is associated with inflammation and increased mortality

BACKGROUND: Adipose tissue in overweight patients with end-stage renal disease (ESRD) is a source of proinflammatory mediators, which could contribute to protein-energy wasting (PEW), cardiovascular disease, and increased mortality. Overweight in ESRD patients, however, is reported to be associated with better survival. OBJECTIVE: We investigated the associations between overweight [body mass index (BMI; in kg/m²) > 25], inflammation, PEW, and mortality in ESRD patients starting dialysis. DESIGN: In 328 ESRD patients (age: 53 ± 12 y; 201 men), inflammatory biomarkers, nutritional status, and dual-energy X-ray absorptiometry data were analyzed close to the start of treatment. We compared clinical and laboratory data in patients in 3 BMI groups, with and without PEW. RESULTS: The prevalence of PEW was high in patients in all 3 BMI groups. PEW was associated with both high fat body mass index (FBMI) and low lean body mass index (LBMI). Both PEW and high BMI were associated with inflammation. The highest concentrations of inflammatory mediators and the highest FBMI were seen in overweight patients with PEW. BMI as such did not predict clinical outcome; however, for each BMI group, the presence of PEW was associated with increased mortality. With BMI 20-25 as the reference group, BMI < 20 did not predict mortality, overweight (BMI > 25) was associated with a survival advantage, and low FBMI was found to be an independent predictor of mortality. CONCLUSIONS: PEW is common in overweight ESRD patients and is associated with high FBMI, low LBMI, and inflammation. PEW was a predictor of mortality in both obese and nonobese sarcopenia patients. BMI as such, however, was a poor predictor of mortality, but after adjustment for various confounders, including PEW, a high BMI and a high FBMI were associated with survival advantage.