C-reactive protein is a significant predictor of decrease in fat mass in hemodialysis patients.

ABSTRACT

Malnutrition and inflammation are common in hemodialysis patients, and are usually closely associated. We examined annual body fat mass changes, a possible nutritional parameter, in maintenance hemodialysis patients, and investigated the factors affecting such changes. Body fat mass of 454 hemodialysis patients (61+/-11 years, 269 males and 185 females) was measured twice by dual energy X-ray absorptiometry (DEXA), with a 12-month interval between measurements. In a total of 65 patients with hemodialysis duration of less than 1 year at the first measurement, fat mass at the second measurement had increased significantly over the course of a year (P<0.0001). In contrast, in a total of 389 patients with hemodialysis duration of more than 1 year at the first measurement, fat mass at the second measurement significantly decreased (P<0.005). In the 389 patients, significant negative correlations were seen between fat mass changes and CRP (r=-0.165, P<0.005). In a multiple regression analysis, CRP was a significant factor (beta=-0.163, P<0.005) affecting fat mass changes, independent of other confounding clinical factors (R(2)=0.127, P<0.001). These results show that body fat mass of long-term hemodialysis patients decreases after an initial increase in the first to second years of hemodialysis. In hemodialysis patients, fat mass change appears to be a parameter indicative of nutritional changes. Chronic inflammation, represented by higher CRP levels, is a significant factor affecting decrease in fat mass, and is related to poorer nutritional status.