Associação de FGF-23 sérico com adiposidade corporal e leptina em pacientes em diálise peritoneal

Abstract

Elevated fibroblast growth factor (FGF-23) serum concentrations, which are a common finding in patients with chronic kidney disease on maintenance dialysis, appear to be related to nutritional status in this population. FGF-23 concentrations have been positively associated with left ventricular hypertrophy. This relationship reinforces the hypothesis of FGF23 action in other tissues, beyond the kidneys, its main target. However, to the best of our knowledge, there are no studies investigating whether there is an association between the adipose tissue amount and serum FGF-23 and leptin concentration in patients on peritoneal dialysis (PD). Objective: To evaluate the association of FGF-23 with adiposity and leptin in PD patients. Material and methods: This cross-sectional study enrolled adult patients on PD for at least 3 months. To assess adiposity, dual X-ray energy absorptiometry and anthropometry were used. The adiposity parameters considered were: total body fat (kg), trunk fat (kg), fat percentage and waist circumference. Serum FGF-23 and leptin were quantified by ELISA. Results: 50 patients were included, with a mean age 55.7 ± 16.2 years, 52% female. A negative correlation was observed between FGF-23 and trunk fat (r=-0.293; p=0.043). There was no significant correlation 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. FGF-23 was inversely associated with total body fat (𝛽=-0.341; 95% CI -0.439; - 0.020; p=0.033) and waist circumference (𝛽=-0.355; 95% CI -0.0242; -0.005; p= 0.042) after including leptin concentrations as an independent variable. Conclusion: An inverse association was found between FGF-23 and total body fat and waist circumference. This association was independent of leptin concentration. More studies are needed to clarify the mechanisms of this association