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

Background: Fibroblast 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.

Methods: A total of 150 consecutive patients with pHPT were examined with ambulatory blood pressure monitoring ((24h)ABP) before parathyroid adenomectomy (PTX). Blood samples were collected 6 ± 2 weeks before and 6 ± 2 weeks after PTX.

Results: Plasma 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 (24h)ABP, especially at nighttime (r = 0.31 and r = 0.28; P ≤ .01), whereas after multivariate adjustment, only PTH remained independently associated with (24)ABP.

Conclusion: Circulating 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.