Survival predictability of lean and fat mass in men and women undergoing maintenance hemodialysis

Background Larger body size is associated with greater survival in maintenance hemodialysis (MHD) patients It is not clear how lean body mass (LBM) and fat mass (FM) compare in then associations with survival across sex in these patients Objective We examined the hypothesis that higher FM and LBM are associated with greater survival in MHD patents irrespective of sex Design In 742 MHD patients, including 31% African Americans with a mean (+/- SD) age of 54 +/- 15 y we categorized men (n = 391) and women (n = 351) separately into 4 quartiles of near infrared interactance-measured LBM and FM Cox proportional hazards models estimated death hazard ratios (HRs) (and 95% CIs) and cubic spline models were used to examine associations with mortality over 5 y (2001-2006) Results After adjustment for case mix and inflammatory markers the highest quartiles of FM and LBM were associated with greater survival in women HRs of 0 38 (95% CI 0 20, 0 71) and 0 34 (95% CI 0 17 0 67) respectively (reference first quartile) In men, the highest quartiles of FM and percentage FM (FM%) but not of LBM were associated with greater survival HRs of 0 51 (95% CI 0 27 0 96) 045 (95% CI 023 0 88) and 1 17 (95% CI 060 2 27), respectively Cubic spline analyses showed greater survival with higher FM% and higher FM minus LBM percentiles in both sexes whereas a higher LBM was protective in women Conclusions In MHD patients, higher FM in both sexes and higher LBM in women appear to be protective The survival advantage of FM appears to be superior to that of LBM Clinical trials to examine the outcomes of interventions that modify body composition in MHD patients are indicated Am J Clin Nutr 2010 92 1060-70