Racial differences in arterial stiffness and microcirculatory function between Black and White Americans

Area of Science:

• Cardiovascular Science
• Vascular Biology
• Racial Health Disparities

Background:

• Black Americans experience a disproportionately high burden of cardiovascular disease (CVD).
• Racial disparities in CVD prevalence may stem from underlying differences in vascular function.

Purpose of the Study:

• To investigate racial differences in vascular function between Black and White individuals.
• To determine if impaired vascular function in Black individuals persists after accounting for traditional cardiovascular disease risk factors.

Main Methods:

• Vascular function was assessed in 385 Black and 470 White subjects using digital pulse amplitude tonometry (EndoPAT) and applanation tonometry (Sphygmocor).
• Key measures included reactive hyperemia index (RHI) for microvascular endothelial function, augmentation index (PAT-AIx, C-AIx) for arterial wave reflections, and pulse-wave velocity (PWV) for arterial stiffness.

Main Results:

• Black individuals had significantly lower RHI, greater PAT-AIx and C-AIx, and higher PWV compared to White individuals.
• These associations remained significant after adjusting for traditional CVD risk factors.
• Impaired vascular function was observed even in healthy Black individuals without traditional CVD risk factors.

Conclusions:

• Black race is independently associated with impaired microvascular endothelial function, increased arterial wave reflections, and greater arterial stiffness.
• These vascular impairments may represent key mechanisms underlying the elevated CVD risk observed in Black populations.