Management of hypertension is vital among African Americans in order to reduce incidence of cardiovascular disease (CVD) and associated death, since there is a high prevalence of high blood pressure (BP) within this ethnic group. Ms. Anh N. Do, doctoral student, and Dr. Ryan Irvin, assistant professor, in the department of epidemiology at the University of Alabama at Birmingham, report in a recent study that “[g]enetic variants have been found to be associated with BP response to treatment. Previous pharmacogenetic studies of BP response to treatment in African Americans suffer limitations of small sample size as well as a limited number of candidate genes, and often focused on one antihypertensive treatment.”
Using data from the Genetics of Hypertension Associated Treatments (GenHAT) study regarding 1,131 African-American participants who had never received treatment for hypertension, the researchers assessed if variants in 35 candidate genes might influence BP response to four antihypertensive medications — including lisinopril (an angiotensin-converting enzyme inhibitor), amlodipine (a calcium channel blocker), and doxazosin (an a-adrenergic blocker) — compared with chlorthalidone (a thiazide diuretic) at follow-up after six months.
The team found that “[s]everal suggestive gene by treatment interactions were identified. For example, among participants with two minor alleles of renin [gene] rs6681776 [variant], diastolic BP response was much improved on doxazosin compared with chlorthalidone (on average -9.49 mm Hg vs -1.70 mm Hg) (P=0.007). Although several suggestive loci were identified, none of the findings passed significance criteria after correction for multiple testing. Given the impact of hypertension and its sequelae in this population, this research highlights the potential for genetic factors to contribute to BP response to treatment.”
They state that continued research focusing on genetics is key to enhancing response to treatment among African Americans.
UAB co-investigators are department colleague Mr. Steven A. Claas, program manager; and Dr. Hemant K. Tiwari, professor, in the department of biostatistics. Dr. Donna K. Arnett, former chair and professor in UAB’s department of epidemiology and current dean of the University of Kentucky’s School of Public Health, also contributed to the study.
“The Effects of Genes Implicated in Cardiovascular Disease on Blood Pressure Response to Treatment among Treatment-Naïve Hypertensive African Americans in the GenHAT Study” was published online in January in the Journal of Human Hypertension.