Insulin resistance and muscle wasting in non-diabetic end-stage renal disease patients

BACKGROUND: Insulin resistance (IR) is prevalent in uraemia. Recent experimental studies suggested IR to be a central mechanism for uraemic malnutrition. However, it is not known whether IR is related to muscle wasting in non-diabetic end-stage renal disease (ESRD) patients. METHODS: We cross-sectionally assessed IR and muscle wasting in 21 non-diabetic ESRD patients who admitted for the initiation of dialysis. For the assessment of muscle wasting, lean body mass was measured (LBMm) by dual energy X-ray absorptiometry and compared with the estimated LBM (LBMe) from the prediction equation derived from healthy controls using the ratio of LBMm/LBMe. For measurement of IR, the homoeostasis model (HOMA-IR) was used. In addition, among patients who chose continuous ambulatory peritoneal dialysis, muscle was sampled during catheter insertion from the rectus abdominis to measure 14-kDa actin fragments, a marker of muscle protein degradation. RESULTS: Patients with a low LBMm/LBMe ratio (<1.00) showed higher HOMA-IR and fat mass (FM) (% body weight) and lower LBM (% body weight) than those with a high LBMm/LBMe ratio (>or=1.00). LBMm/LBMe ratio was negatively correlated with HOMA-IR, regardless of obesity. By multiple regression analysis, HOMA-IR was an independent factor affecting LBMm/LBMe ratio. Furthermore, in the muscle samples, patients with high HOMA-IR had lower LBMm/LBMe ratios and stronger bands for the 14-kDa actin fragments than did patients with low HOMA-IR. CONCLUSION: These results suggest that IR seems to be associated with muscle wasting in non-diabetic ESRD patients.