Racial Differences in Arterial Stiffness and Microcirculatory Function Between Black and White Americans

Abstract

BackgroundCompared with whites, black Americans suffer from a disproportionate burden of cardiovascular disease (CVD). We hypothesized that racial differences in the prevalence of CVD could be attributed, in part, to impaired vascular function in blacks after adjustment for differences in risk factor burden.Methods and ResultsWe assessed vascular function in 385 black and 470 white subjects (mean age, 48±11 years; 45% male). Using digital pulse amplitude tonometry (EndoPAT) we estimated the reactive hyperemia index (RHI), a measure of microvascular endothelial function, and peripheral augmentation index (PAT‐AIx). Central augmentation index (C‐AIx) and pulse‐wave velocity (PWV) were measured as indices of wave reflections and arterial stiffness, respectively, using applanation tonometry (Sphygmocor). Compared with whites, blacks had lower RHI (2.1±0.6 versus 2.3±0.6, P<0.001), greater arterial wave reflections assessed as both PAT‐AIx (20.4±21.5 versus 17.0±22.4, P=0.01) and CAIx (20.8±12.3 versus 17.5±13.3, P=0.001), and greater arterial stiffness, measured as PWV (7.4±1.6 versus 7.1±1.6 m/s, P=0.001). After adjustment for traditional CVD risk factors, black race remained a significant predictor of lower RHI and higher PAT‐AIx and CAIx (all P<0.001) in all subjects and of higher PWV in men (P=0.01). Furthermore, these associations persisted in a subgroup analysis of “healthy” individuals free of CVD risk factors.ConclusionBlack race is associated with impaired microvascular vasodilatory function, and greater large arterial wave reflections and stiffness. Because impairment in these vascular indices may be associated with worse long‐term outcomes, they may represent underlying mechanisms for the increased CVD risk in blacks.

Low testosterone in men predicts impaired arterial elasticity and microvascular function

“…Indices of arterial stiffness and wave reflections (pulse wave velocity, PWV, and the augmentation index, AIX, respectively) were estimated in the supine position after an overnight fast using the SphygmoCor device (AtCor Medical, Australia), which records sequential high-quality pressure waveforms at peripheral pulse sites using a high-fidelity tonometer as described previously [25,29,30]. In brief, PWV measures the rate at which systolic pressure waveforms move down the vasculature as a measure of arterial compliance.…”

“…After a 10 min equilibration period, the cuff of the study arm was then inflated to suprasystolic pressure producing hyperemia distally. Full details of the probe technology and the basis of measurements have been described previously [30].…”

Arterial stiffness as a noninvasive tissue biomarker of cardiac target organ damage

“…153 Several studies note increased arterial stiffness, augmented pressure from wave reflections, and lower PP amplification in African Americans. [154][155][156][157][158] Interestingly, these detrimental modulations are directly associated with wasted LV pressure effort, 159,160 increased myocardial work, reduced coronary perfusion, 160 and cTOD, 161,162 even in individuals with brachial BP within accepted normal reference ranges. Racial differences in arterial stiffness manifest at an early age, 163 and subsequent changes in central pressures are associated with LV mass in young African American adolescents.…”

Estudo das propriedades mecânicas das células de músculo liso vascular em situações fisiológicas e patológicas

“…A ancestralidade racial individual está associada à estrutura e à funcionalidade de vasos, tanto da macrovasculatura quanto da microvasculatura (80). Indivíduos de raça preta* 1 apresentam artérias com menor capacidade de dilatação a estímulos vasodilatatórios e maior capacidade de contração a estímulos agonistas de CMLV (81-83), além de maior rigidez arterial proximal em relação a indivíduos brancos (80,84).…”

“…Indivíduos de raça preta* 1 apresentam artérias com menor capacidade de dilatação a estímulos vasodilatatórios e maior capacidade de contração a estímulos agonistas de CMLV (81-83), além de maior rigidez arterial proximal em relação a indivíduos brancos (80,84). Existe a hipótese de que o aumento da atividade de enzima creatino-quinase (CK) nas CMLV responda por parte das alterações encontradas (85).…”