Abstract: FR-PO170
Serum Phosphate and Microvascular Function in a Population-Based Cohort: The Maastricht Study
Session Information
- Bone and Mineral Metabolism: Phosphorus, FGF23, Vascular Calcification
November 08, 2019 | Location: Exhibit Hall, Walter E. Washington Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Bone and Mineral Metabolism
- 402 Bone and Mineral Metabolism: Clinical
Authors
- Ginsberg, Charles, UCSD, San Diego, California, United States
- Houben, Alfons Jhm, Maastricht University, Maastricht, Netherlands
- Malhotra, Rakesh, UCSD, San Diego, California, United States
- Berendschot, Tos, Maastricht University, Maastricht, Netherlands
- Kooman, Jeroen, Maastricht University, Maastricht, Netherlands
- Webers, Carroll A.b., University Eye Clinic Maastricht, Maastricht, Netherlands
- Stehouwer, Coen, Maastricht University, Maastricht, Netherlands
- Ix, Joachim H., UCSD, San Diego, California, United States
Background
Higher serum phosphate is associated with cardiovascular events and all-cause mortality. Explanations of this association have focused on large vessel-calcification and stiffness. Studies suggest that higher serum phosphate induces microvascular dysfunction, but relationships in humans with direct measures of microvascular function are lacking.
Methods
We performed a cross-sectional analysis of 3,189 community-living participants that underwent skin capillaroscopy, laser-Doppler flowmetry, or flicker-light induced retinal vessel responses. The primary outcome was capillary recruitment during post-occlusive peak reactive hyperemia by capillaroscopy. Secondary outcomes included capillary recruitment during venous congestion, heat-induced skin hyperemic response, flicker-light induced retinal arteriolar and venular dilation.
Results
The mean age of the cohort was 59 years, 48% were women, 7% had an eGFR< 60ml/min/1.73 m2, and the mean serum phosphate concentration was 3.2±0.5 mg/dl. A 1 mg/dl higher serum phosphate was independently associated with a 5.0% lower post-occlusive capillary recruitment (95%CI -10.0%,-0.1%). Results were similar for capillary recruitment with venous congestion (Table). A 1 mg/dl higher serum phosphate was also independently associated with a 0.23% lower retinal venular dilation in response to flicker-light (95%CI -0.44%,-0.02%). A higher serum phosphate was not associated with change in flicker-light induced retinal arteriolar dilation or heat-induced skin hyperemic response, however a higher serum phosphate was associated with a lower heat-induced skin hyperemic response among men (-149% 95%CI -260,-38, per 1 mg/dl higher serum phosphate).
Conclusion
Higher serum phosphate concentrations are associated with microvascular dysfunction in community-living individuals.
Adjusted Association of Phosphate with Microvascular Measurements
| Measurement Technique | Per 1 mg/dl higher Phosphate | P |
| % Capillary Recruitment during Post-Occlusive Reactive Hyperemia | -5.0(-10.0, -0.1) | 0.04 |
| % Capillary Recruitment during Venous Congestion | -4.5(-9.8, 0.7) | 0.09 |
| % Heat-Induced Skin Hyperemic Response | - 25(-113, 63) | 0.57 |
| % Retinal Arteriolar Dilation | -0.12(0.3, 0.15) | 0.39 |
| % Retinal Venular Dilation | -0.23(-0.44, -0.02) | 0.03 |
Adjusted for age, sex, smoking, systolic blood pressure, anti-hypertensives, lipid medications, glucose metabolism, eGFR and serum calcium
Funding
- NIDDK Support