Association between body adiposity and fibroblast growth factor 23 (FGF-23) in patients on peritoneal dialysis: an exploratory analysis

Abstract Background Elevated serum concentrations of fibroblast growth factor 23 (FGF-23) are commonly observed in patients with chronic kidney disease on dialysis and appear to be associated with leptin levels and adipose tissue in this population. Therefore, this study aims to explore the association of FGF-23 with body adiposity and leptin in patients undergoing peritoneal dialysis. Methods This cross-sectional study included adult patients on peritoneal dialysis for at least 3 months. Adiposity was assessed by waist circumference and dual-energy X-ray absorptiometry. The adiposity parameters considered were total fat mass, trunk fat mass, body fat percentage, and waist circumference. Results A total of 50 patients on peritoneal dialysis were included, mean age 55.7 ± 16.2 years, 52% female. A correlation was observed between FGF-23 and trunk fat mass ( r = −0.293; p = 0.043). No significant correlation was found between FGF-23 and the other adiposity parameters. In multiple linear regression models adjusted for sex, FGF-23 was not significantly associated with adiposity parameters. However, after adjustment for leptin concentrations, FGF-23 showed an inverse association with total body fat ( β = −0.341; p = 0.033) and waist circumference ( β = −0.355; p = 0.042). Conclusions An inverse association between FGF-23 and body adiposity parameters was observed in patients on peritoneal dialysis after adjustment for leptin concentrations. Further studies are needed to clarify the mechanisms of this association.