Association of fibroblast growth factor-23 with arterial stiffness in the Multi-Ethnic Study of Atherosclerosis.

BACKGROUND Serum fibroblast growth factor-23 (FGF-23) is associated with cardiovascular disease (CVD), yet the mechanisms remain uncertain. Our objective was to determine whether higher FGF-23 concentrations are associated with arterial stiffness. METHODS In this cross-sectional study, serum FGF-23 concentrations were measured in 5977 participants without known CVD in the Multi-Ethnic Study of Atherosclerosis. The primary outcomes of interest were large (LAE) and small artery elasticity (SAE), pulse pressure and ankle-brachial index (ABI) > 1.30. LAE and SAE were measured by pulse contour analysis of the radial artery. Pulse pressure was measured with an automated sphygmomanometer using the average of two resting blood pressure measurements. ABI was calculated as the ratio of the ankle and brachial systolic blood pressures. RESULTS Serum FGF-23 concentrations were not significantly associated with LAE [relative difference (RD) per doubling: 0%; 95% confidence interval (CI): -2-1%], SAE (RD per doubling: 0%; 95% CI: -3-2%), pulse pressure (β per doubling: 0.44; 95% CI: -0.31-1.19), or a high ABI (odds ratio per doubling: 1.14; 95% CI: 0.84-1.55). Findings were similar irrespective of chronic kidney disease status. CONCLUSIONS Higher serum FGF-23 concentrations are not associated with arterial stiffness, as measured by pulse pressure, LAE, SAE or high ABI, in a community-based population without CVD.