Change in body composition in accordance with residual renal function in patients on peritoneal dialysis

The aim of this study is to evaluate changes in body composition in accordance with residual renal function (RRF).

Two hundred forty-four patients with more than 1 year of follow-up were enrolled. The mean value of RRF at peritoneal dialysis (PD) initiation and 1 year after PD initiation was used as an indicator of the time-averaged RRF (TA-RRF). The patients were divided into 3 groups with respect to the tertile of the TA-RRF level: low tertile (n = 81), middle tertile (n = 82), and high tertile (n = 81). Body composition measurement was determined from dual-energy X-ray absorptiometry and bioimpedance analysis. This analysis was performed at PD initiation and 1 year after PD initiation.

Multivariate analysis showed that the high TA-RRF tertile was associated with an increase in lean mass index. Fat mass index in all tertiles and bone mineral content index in the middle and high TA-RRF tertiles were increased, but no significant difference were observed in these changes among the 3 tertiles. The edema index decreased over the 1-year PD period. The high TA-RRF tertile was associated with a lower edema index. Although there was no statistical significance, the increase in fat mass/lean mass ratio (FM/LM) attenuated as the grade of TA-RRF tertile increased. The increase in fat mass index was similar to the trend in FM/LM.

TA-RRF was associated with an increase in total lean mass and a decrease in edema index.