Prealbumin is associated with visceral fat mass in patients receiving hemodialysis

Objective: Albumin and prealbumin are associated with nutritional status and inflammatory status. Each has a residual effect on mortality outcomes when included in regression models that include the other. Prealbumin is increased in the obese mouse model as a consequence of stabilization of prealbumin by retinol binding protein 4 (RBP4) secreted by adipocytes. We carried out this study to establish the contribution of adiposity to prealbumin levels in prevalent patients receiving dialysis and the relationship of prealbumin to RBP4. Design and Methods: We determined whether prealbumin was associated with adiposity in patients receiving hemodialysis (HD), controlling for the effects of inflammation and nutrition. We evaluated body composition in 48 prevalent patients receiving HD by magnetic resonance imaging (MRI), measuring total skeletal muscle mass (SM), visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and serum albumin, prealbumin, RBP4, and interleukin-6 (IL-6) levels. We used normalized protein catabolic rate (nPCR) to report nutrition and separately analyzed the determinants of albumin and then of prealbumin by multiple stepwise regression. Results: Thirty-two patients were women, 16 patients were diabetic, and median age and body mass index were 54.5 and 27.3 kg/m², respectively. Median total adipose tissue (TAT) was 24.3 kg and VAT was 3.25 kg. Prealbumin was positively associated with VAT, nPCR, and RBP4 and was negatively associated with IL-6; r² for the model was 0.64. By contrast, albumin was positively associated with nPCR and negatively associated with IL-6 but not with any measure of adiposity (r² for the model=0.2). Conclusions: Prealbumin, like albumin, is associated with markers of nutrition (nPCR) and inflammation, but unlike albumin, prealbumin levels are positively associated with visceral adiposity.