Effect of African-American Race and Hypertensive Left Ventricular Hypertrophy on Coronary Vascular Reactivity and Endothelial Function

Houghton, Jan L.; Smith, Vivienne E.; Strogatz, David; Henches, Nancy L.; Breisblatt, Warren M.; Carr, Albert A.

doi:10.1161/01.hyp.29.3.706

Cited by 49 publications

(26 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The findings of the current study may be more reliable because of our relatively large sample size and certainly suggest that not all black normotensive subjects have impaired vasodilator function. Notably, our findings are also consistent with work by Houghton and colleagues 22 demonstrating no racial differences in acetylcholine-mediated and adenosine-mediated dilation of coronary resistance vessels.…”

Section: Discussionsupporting

confidence: 93%

Effects of Black Race on Forearm Resistance Vessel Function

et al. 2002

View full text Add to dashboard Cite

Abstract-Presentation, response to therapy, and clinical outcome in hypertension differ according to race, and these observations could relate to differences in microvascular function. We examined forearm microvascular function in age-matched black (nϭ56) and white subjects (nϭ62) using intra-arterial agonist infusion and venous occlusion plethysmography. In normotensive subjects (nϭ70; 34 black and 36 white normotensives), methacholine-, sodium nitroprusside-, and verapamil-induced vasodilation was equivalent in black and white subjects. In hypertensive subjects (nϭ48; 22 black and 26 white hypertensives), the vasodilator response to methacholine was markedly lower in black subjects compared with white subjects (PϽ0.001). The vasodilator responses to sodium nitroprusside and verapamil, however, were equivalent in black and white hypertensive subjects. Acute ascorbic acid infusion improved the methacholine response equally in black and white hypertensive patients, suggesting that a difference in a rapidly reversible form of oxidative stress does not explain these findings. Thus, the present study demonstrates important racial differences in vascular function and a marked impairment in endothelial vasomotor function in black patients with hypertension. Further studies will be required to elucidate the mechanisms and determine whether these insights will lead to more appropriately tailored management of hypertension and its complications.

show abstract

Section: Discussionsupporting

confidence: 93%

Effects of Black Race on Forearm Resistance Vessel Function

et al. 2002

View full text Add to dashboard Cite

show abstract

“…As previously reported in an interim publication, 19 we found no significant racial differences in conduit-and resistance-vessel vasoreactivity among normotensive subjects. The smaller number of normotensive study subjects (particularly among African Americans) reduces the statistical power of analyses in this subgroup, but the available data do not suggest racial differences in coronary vasoreactivity in normotensives.…”

Section: Discussionsupporting

confidence: 87%

“…Furthermore, quality of measurement was previously shown to be consistent throughout the study period. 19 We acknowledge that angiographic assessment is insensitive for detection of atherosclerosis. However, patient groups such as ours with no angiographic CAD, yet endothelial dysfunction, are conjectured to represent an early stage in the natural history of CAD and/or cardiomyopathy, populations of enormous importance in preventive cardiology, where early diagnosis and individualized therapy might be especially efficacious.…”

Section: Discussionmentioning

confidence: 98%

“…We previously reported interim findings in 80 subjects, showing that African American race was not associated with excess intrinsic or acquired depression in maximum coronary vascular relaxation during peak effect of the endothelium-dependent and -independent agonists, acetylcholine and adenosine. 19 However, the interim report was not statistically powered to test for racial differences in the overall dose-response curve or in sensitivity to submaximal infusions of acetylcholine among hypertensive and normotensive subgroups. Thus, the purpose of this article is to report the final results of these analyses in 195 similar African American and white subjects with normal coronary arteries.…”

mentioning

confidence: 99%

See 1 more Smart Citation

African Americans With LVH Demonstrate Depressed Sensitivity of the Coronary Microcirculation to Stimulated Relaxation

Houghton

Strogatz²,

Torosoff³

et al. 2003

Hypertension

Self Cite

View full text Add to dashboard Cite

Abstract-Excess coronary heart disease morbidity and mortality among African Americans remains an important yet unexplained public health problem. We hypothesized that adverse outcome is in part due to intrinsic or acquired abnormalities in coronary endothelial function and vasoreactivity. We compared dose-response curves relating changes in coronary blood flow and epicardial diameter to graded infusions of acetylcholine in 50 African American and 65 white subjects with hypertensive left ventricular hypertrophy (LVH) and normal coronary arteries. These groups were similar for age, body mass index, mean arterial pressure, and indexed left ventricular mass. The same protocol was conducted in 24 normotensive African American and 56 similar white subjects. We found significant depression in the coronary blood flow dose-response curve relation among African Americans when compared with white subjects with similar LVH (PϽ0.03). Racial differences were observed at all doses of acetylcholine but were less precisely estimated at the highest dose. The same testing among normotensive subjects revealed similar dose-response curves with no significant effect of race. Qualitatively similar results were found with respect to coronary diameter. Adenosine responses, a measure of endothelium-independent function, were similar after partitioning by LVH. Our study demonstrates that there are racial differences in sensitivity of coronary arteries to acetylcholine-stimulated relaxation among those with LVH. These results provide a mechanism whereby racial differences in coronary vasoreactivity might contribute to adverse coronary heart disease outcome among African Americans, a group in whom LVH is prevalent.

show abstract

“…[86][87][88][89] In contrast to the studies performed in the forearm microvasculature, studies on coronary microvasculature resistance have shown that there are no racial differences between NTS AAs and NTS EAs in response to acetylcholine-induced (endotheliumdependent) or adenosine-induced (endothelium-independent) vasodilation. 87-89 Also, there are no differences in vascular reactivity to acetylcholine or adenosine between AA and EA women with chest pain, 86 although this study had a very small study population.…”

Section: Racial Differences In Vascular Reactivitymentioning

confidence: 94%

Racial Differences in Nitric Oxide—Dependent Vasorelaxation

Mata‐Greenwood

Chen

2008

Reprod. Sci.

View full text Add to dashboard Cite

Along with the growing heterogeneity of the American population, ethnic/racial disparity is becoming a clear health issue in the United States. The awareness of ethnic/racial disparities has been growing because of considerable data gathered from recent clinical and epidemiological studies. These studies have highlighted the importance of addressing these differences in the diagnosis and treatment of various diseases potentially according to race. It is becoming particularly clear that there is a 2-to 3-fold racial difference in certain cardiovascular diseases (eg, preeclampsia) associated with dysfunctional nitric oxide-mediated vasodilation. In this review, the authors summarize the current literature on racial disparities in nitric oxide-mediated vasodilation in relation to cardiovascular health with an emphasis on vascular nitric oxide bioavailability as a balance between production via endothelial nitric oxide synthase and degradation through reactive oxygen species. The major hypotheses postulated on the biological basis of these differences are also highlighted. KeywordsRace; nitric oxide; endothelial nitric oxide synthase Nitric oxide (NO) was discovered in 1988 as the vascular endothelial cell-derived factor that causes relaxation of the underlying vascular smooth muscle. 1-3 NO dilates all types of blood vessels by stimulating soluble guanylate cyclase that produces cyclic guanosine monophosphate in smooth muscle cells. 3 In addition to its vasodilatory properties, NO exerts some anti-inflammatory effects in the blood vessel wall by inhibiting leukocyte adhesion to the endothelium. 4 NO also inhibits platelet adhesion and activation, thereby acting as an antithrombotic factor. 5 NO inhibits smooth muscle cell proliferation and migration and regulates the expression of certain proteins involved in vessel wall remodeling, thereby contributing to the control of vascular compliance. 6 Other functions of NO not related to the cardiovascular system include regulation of neuronal proliferation/differentiation, 7 sexual function, 8 insulin release, 9 and immune responses in inflammation. 10 NO participates in a broad spectrum of physiologic and pathophysiologic processes, 11 such as neurodegeneration and memory function, 12,13 pulmonary vascular remodeling and apoptosis, 14 atherosclerosis, 15 and exercise-induced cardioprotection. 16 Impairment of NO bioavailability leads to endothelial dysfunction and is a pivotal event in the pathogenesis of many cardiovascular diseases such as hypertension, heart failure, and coronary artery disease. 17-19 NO-dependent endothelial dysfunction has also been associated with a range of other disorders such as pulmonary hypertension, 20 asthma, 14,20 erectile dysfunction, 8 preeclampsia, 21 and insulin resistance and diabetes mellitus. 9The ethnic/racial impact on health has been receiving considerable attention in recent years. The phenomenon of ethnic health disparities in cardiovascular and many other diseases is becoming clear, and awareness of the importance in ad...

show abstract

Effect of African-American Race and Hypertensive Left Ventricular Hypertrophy on Coronary Vascular Reactivity and Endothelial Function

Cited by 49 publications

References 38 publications

Effects of Black Race on Forearm Resistance Vessel Function

Effects of Black Race on Forearm Resistance Vessel Function

African Americans With LVH Demonstrate Depressed Sensitivity of the Coronary Microcirculation to Stimulated Relaxation

Racial Differences in Nitric Oxide—Dependent Vasorelaxation

Contact Info

Product

Resources

About