January 20, 2021
African Americans have a disproportionately higher rate of coronary heart disease (CHD) mortality and incidence compared to their non-Hispanic white counterparts. This disparity persists even after accounting for health and lifestyle factors associated with CHD, leading Dr. Hyacinth I. Hyacinth of the University of Cincinnati College of Medicine and his team to question whether underlying genetic factors, in particular, sickle cell trait might contribute. Sickle cell trait occurs when an individual inherits one copy of a normal adult hemoglobin gene and one copy of the sickle cell variant from their parents. The prevalence of sickle cell trait in African Americans is about 8%, but 20-35% in Africans. While inheriting two sickle cell variants from each parent results in sickle cell disease, being a carrier of one copy of the variant has been generally regarded as benign. However, emerging research has suggested potential associations between sickle cell trait in African Americans and adverse clinical outcomes, such as chronic kidney disease, elevated C-reative protein levels, pulmonary embolism and even sudden death.
Given the recent associations found between between sickle cell trait and various biomarkers for cardiovascular disease, Dr. Hyacinth and his collaborators conducted an analysis to examine whether sickle cell trait was associated with a higher risk of myocardial infarction (MI) and CHD. They evaluated 23,197 African Americans from five large, population-based cohort studies, including 5,904 women from the WHI study. In their analysis, which included examining data from each study separately as well as combining the data from all five studies, they found that African American individuals with sickle cell trait did not have a higher incidence of MI or CHD and concluded these cardiovascular disorders might not be related to sickle cell trait-related sudden death.
This study was published in JAMA Network Open in January 2021.
The WHI program is funded by the National Heart, Lung, and Blood Institute, National Institutes of Health, U.S. Department of Health and Human Services.
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