Impact of Bioelectrical Impedance–Guided Fluid Management and Vitamin D Supplementation on Left Ventricular Mass in Patients Receiving Peritoneal Dialysis: A Randomized Controlled Trial

Abstract

Rationale & Objective: Hypervolemia and vitamin D deficiency occur frequently in patients receiving peritoneal dialysis and may contribute to left ventricular (LV) hypertrophy. The effect of bioelectrical impedance analysis (BIA)-guided volume management or vitamin D supplementation on LV mass among those receiving peritoneal dialysis is uncertain. Study Design: Two-by-two factorial randomized controlled trial. Setting & Participants: Sixty-five patients receiving maintenance peritoneal dialysis. Intervention: BIA-guided volume management versus usual care and oral cholecalciferol 50,000 U weekly for 8 weeks followed by 10,000 U weekly for 44 weeks or matching placebo. Outcome: Change in LV mass at 1 year measured by cardiac magnetic resonance imaging. Results: Total body water decreased by 0.9 + 2.4 (SD) L in the BIA group compared with a 1.5 ± 3.4 L increase in the usual care group (adjusted between-group difference: −2.4 [95% CI, −4.1 to −0.68] L, P = 0.01). LV mass increased by 1.3 ± 14.3 g in the BIA group and decreased by 2.4 ± 37.7 g in the usual care group (between-group difference: +2.2 [95% CI, −13.9 to 18.3] g, P = 0.8). Serum 25-hydroxyvitamin D concentration increased by a mean of 17.2 ± 30.8 nmol/L in the cholecalciferol group and declined by 8.2 ± 24.3 nmol/L in the placebo group (between-group difference: 28.3 [95% CI, 17.2-39.4] nmol/L, P < 0.001). LV mass decreased by 3.0 ± 28.1 g in the cholecalciferol group and increased by 2.0 ± 31.2 g in the placebo group (between-group difference: −4.5 [95% CI, −20.4 to 11.5] g, P = 0.6). Limitations: Relatively small sample size with larger than expected variation in change in LV mass. Conclusions: BIA-guided volume management had a modest impact on volume status with no effect on the change in LV mass. Vitamin D supplementation increased serum vitamin D concentration but had no effect on LV mass. Funding: Unrestricted Baxter International extramural grant and the Kidney Foundation of Canada. Trial Registration: Registered at ClinicalTrials.gov with study number NCT01045980.