Fibroblast growth factor 23 and 25(OH)D levels are related to abdominal obesity and cardiovascular risk in patients with polycystic ovarian syndrome

Fibroblast growth factor 23 (FGF23) and Klotho are extensively studied in relation to bone metabolism and progression of chronic kidney disease. There is very limited information about their role in polycystic ovarian syndrome (PCOS). The aim of the present study was to investigate some bone markers in women with PCOS in relation to obesity and cardiovascular risk. In the study were included 80 patients, divided into three age-matched groups -Non-obese PCOS (n = 40); Obese PCOS (n = 20) and Obese control group (n = 20). Bone marker levels were measured by an enzyme-linked immunosorbent assay. Obese PCOS patients had higher levels of FGF23 and sRANKL, lower levels of 25(OH)D and higher prevalence of vitamin D deficiency compared to non-obese subjects. Patients with abdominal obesity (waist circumference >80 cm) independently of PCOS status had significantly higher levels of FGF23 (112.5 +/- 86.5 vs. 73.4 +/- 37.9 pg/ml; p = .023) and lower of 25(OH)D (35.8 +/- 21.4 vs 47.8 +/- 26.5 nmol/l; p = .034). Patients with PCOS at risk of cardiovascular diseases according to AE-PCOS consensus also had increased levels of FGF23 (111.6 +/- 84.5 vs. 66.5 +/- 35.1 pg/ml; p = .031) and decreased levels of 25(OH)D (31.9 +/- 16.8 vs. 47.1 vs 28.4 nmol/l; p = .017) compared to those not at risk. There was no correlation between bone markers and blood glucose levels, insulin resistance or hormonal levels.