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

BACKGROUND

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.

METHODS

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.

RESULTS

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).

CONCLUSIONS

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