Determinants and survival implications of low bone mineral density in end-stage renal disease patients

Reduced bone mineral density (BMD) is common in end-stage renal disease (ESRD) patients and predicts outcomes. The chronic kidney disease-mineral bone disorder contributes to low BMD in ESRD; however, the impact of classical risk factors for osteoporosis in the general population, such as body weight and fat mass, remains less well defined in ESRD subjects.

BMD, body composition (dual-energy X-ray absorptiometry), nutritional status (subjective global assessment), hand grip strength and multiple biomarkers were investigated in 361 patients (218 males; 60.4%) starting on dialysis. The relations between BMD, body composition and biomarkers were analyzed at baseline, and the impact of BMD on mortality was analyzed prospectively.

In univariate analysis, T-score correlated with fat mass (r = 0.308, p<0.001), lean body mass (r = 0.278, p<0.001), leptin (r = 0.124, p = 0.028) as well as the anabolic marker insulin-like growth factor-1 (IGF-1; r = 0.301, p<0.001), and its binding proteins IGFBP-1 (r = -0.342, p<0.001) and IGFBP-3 (0.231, p<0.001). BMD T-score was independently associated with age, total fat mass, intact parathyroid hormone and presence of wasting. During 5 years of follow-up, 87 deaths were recorded. Each unit of increase of T-score was associated with decreased all-cause mortality, which persisted after multivariate adjustment (hazard ratio = 0.824, 95% confidence interval, 0.681-0.996).

BMD is associated with body composition, especially total fat mass, nutritional status and mortality risk in ESRD patients.