Indices of Arterial Stiffness in African American and African Caribbean Subjects

Abstract

African American and African Caribbeans have high cardiovascular morbidity/mortality. Increased arterial stiffness is a marker of subclinical atherosclerosis, predicts higher cardiovascular risk, and causes isolated systolic hypertension. The objectives of the study were to compare arterial stiffness indices in African Americans and African Caribbeans and obtain reference values. We prospectively studied 449 African Americans and 454 African Caribbeans. Using applanation tonometry, mean augmentation index and carotid-to-radial pulse-swave velocity were similar between the 2 groups (23 +/- 15 vs 24 +/- 14%, p = .20) and (9.0 +/- 1.9 vs 9.0 +/- 2.0 m/s, p = .86). On multivariate analysis, age, weight, gender, mean arterial pressure, heart rate, and family history of coronary artery disease were independently associated with augmentation index in African Americans (R2, 0.46) and African Caribbeans (R2, 0.49). Among 94 African American and 98 African Caribbean healthy subjects without cardiovascular risk factors/disease, augmentation index (20 +/- 14 vs 18 +/- 16%, p = .43) and pulse-wave velocity (8.9 +/- 1.9 vs 9.0 +/- 1.5 m/s, p = .92) were similar. Age-based normative values were determined. Augmentation index and pulse-wave velocity and their related clinical factors are similar between African Americans and African Caribbeans. Age, weight, female gender, mean arterial pressure, heart rate, and family history of coronary artery disease are independent predictors of higher augmentation index in African Americans and African Caribbeans. Whether increased arterial stiffness improves risk stratification in these populations merits further study.