Serum 25-hydroxyvitamin D and Ethnic Differences in Arterial Stiffness and Endothelial Function

Area of Science:

• Cardiovascular Health
• Nutritional Science
• Health Disparities

Background:

• Vitamin D influences vascular function, which is generally poorer in African Americans (AAs) compared to European Americans (EAs).
• Ethnic disparities in serum 25-hydroxyvitamin D (25(OH)D) levels and their role in mediating vascular function differences remain unclear.

Purpose of the Study:

• To investigate the association between serum 25(OH)D and vascular function indicators in healthy young AA and EA adults.
• To determine if 25(OH)D levels mediate ethnic differences in vascular health.

Main Methods:

• Cross-sectional study including 23 AAs and 22 EAs.
• Measured outcomes included augmentation index (AIx75), central aortic pressure, pulse wave velocity (PWV), flow-mediated dilation (FMD), and blood pressures.
• Statistical analyses adjusted for age, sex, and body fat percentage.

Main Results:

• Serum 25(OH)D was inversely associated with AIx75, supine SBP, central aortic SBP, and central aortic DBP.
• AAs exhibited greater AIx75 and PWV, and lower FMD compared to EAs.
• Adjusting for 25(OH)D significantly reduced ethnic differences in these vascular parameters.

Conclusions:

• Serum 25(OH)D is associated with vascular function in healthy adults.
• Lower 25(OH)D levels in AAs may contribute to their increased arterial stiffness and reduced endothelial function.
• Findings suggest a potential role for vitamin D status in explaining ethnic variations in vascular health.