Changes in Body Fat Mass in Patients after Starting Peritoneal Dialysis

Background Peritoneal dialysis (PD) is characterized by gain in fat mass. Visceral fat mass is associated with metabolic syndrome and atherosclerosis rather than subcutaneous fat mass. In addition, the change in visceral fat mass is a more reliable predictor of survival in PD patients. In this study, we prospectively examined serial changes in fat composition and nutritional status and analyzed factors associated with gain in fat mass in patients undergoing PD.Methods Body composition was assessed by bioelectric impedance analysis (BIA) and computed tomogram (CT). Nutrition status was assessed by Subjective Global Assessment (SGA), protein equivalent of nitrogen appearance (nPNA), serum albumin, C-reactive protein (CRP), and lipid profile. All measurements except BIA were performed on the seventh day and at 6 and 12 months after the start of PD.Results 60 patients (30 men; mean age 55.0 ± 12.5 years) were enrolled. Increase in body weight continued during the 12 months but visceral and subcutaneous fat mass increased during the first 6 months and decreased during the second 6 months. While hematocrit and serum albumin decreased during the first 6 months, they did not change during the second 6 months. Serum creatinine, total cholesterol, and triglyceride increased similarly to the weight pattern. While nPNA decreased during the 12 months, Kt/V, SGA, and CRP did not change. Patients that had more visceral fat mass at the start of PD had less gain of visceral fat mass during the first 6 months (r= –0.821, p= 0.002). Patients that had more subcutaneous fat mass at the start of PD had less gain of subcutaneous fat mass (r= –0.709, p= 0.015). The change in weight was not associated with the change in visceral or subcutaneous fat during the first 6 months.Conclusion Patients starting PD experience weight gain, including visceral and subcutaneous fat, during the first 6 months of PD. Patients with high baseline fat mass had less increase in fat mass than those with low baseline fat mass, regardless of visceral or subcutaneous fat mass.