FGF23, metabolic risk factors, and blood pressure in patients with primary hyperparathyroidism undergoing parathyroid adenomectomy

BackgroundFibroblast growth factor-23 (FGF23), a regulator of secretion of parathyroid hormone (PTH), is implicated in the development of cardiovascular disease. The role of FGF23 in primary hyperparathyroidism (pHPT) is unclear.MethodsA total of 150 consecutive patients with pHPT were examined with ambulatory blood pressure monitoring (24hABP) before parathyroid adenomectomy (PTX). Blood samples were collected 6 ± 2 weeks before and 6 ± 2 weeks after PTX.ResultsPlasma FGF23 levels decreased after PTX from a median of 45.2 pg/mL (interquartile range 37.6–54.8) to 36.8 pg/mL (26.7–48.7); P < .001. This postoperative decrease correlated with the decrease in ionized calcium (r = 0.24; P < .01). Greater FGF23 concentrations at baseline were associated with a greater weight of the adenoma and PTH levels, as well as with body mass index, triglycerides, and insulin levels and greater postoperative decreases in FGF23, ionized calcium, insulin growth-like factor 1, and insulin. FGF23 and PTH both correlated with greater blood pressures on 24hABP, especially at nighttime (r = 0.31 and r = 0.28; P ≤ .01), whereas after multivariate adjustment, only PTH remained independently associated with 24ABP.ConclusionCirculating FGF23 is increased in pHPT and is associated independently with the metabolic risk profile. The long-term benefit of decreasing FGF23 in pHPT after PTX remains to be established.