March 5, 2018Cardiology
High blood pressure is a leading cause of illness and death worldwide, and managing it is a major public health priority. According to the Centers for Disease Control and Prevention, about 75 million American adults have high blood pressure.
According to an article published in The American Journal of Human Genetics (1 March 2018), using a technique that is opening the door to more complex analyses of the human genome, dozens of new genetic variations have been identified that affect blood pressure. The new genetic regions-have confirmed the role of many previously known ones-by looking specifically at cigarette smoking behavior, one of many lifestyle factors that impact blood pressure. According to the authors, the findings could eventually lead to the development of individually targeted treatments to manage hypertension.
By using the technique known as gene-environment interaction analysis, the authors used cigarette smoking as an environmental marker to zero in on areas of the genome associated with blood pressure. Since it is well-established that cigarette smoking raises blood pressure, the authors tested different points of the genome of more than 610,000 individuals to find where there were interactions between cigarette smoking and blood pressure. These would be the areas where genes regulate blood pressure. Results confirmed 56 known genetic regions and identified 83 novel ones associated with blood pressure. The discovery was possible because the effects of some genes on blood pressure only show up under certain environmental factors, such as cigarette smoking. Absent those conditions, those genes' connection to hypertension could have gone unnoticed. The same is true for the more detailed insights related to cigarette smoking that the authors were able to glean. Ten of the newly discovered genes appeared to have a much larger impact on the blood pressure levels of smokers than of nonsmokers-in some cases as much as eight times higher. The analysis of the large samples was possible through the work of researchers in the Gene-Lifestyle Interactions Working Group of the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) Consortium. Also funded by NHLBI, CHARGE was formed to facilitate genome-wide association meta-analyses, using several large longitudinal studies.
In future studies, the authors will use even larger sample sizes and investigate the influence of other lifestyle factors on blood pressure and lipids.