Higher body mass index (BMI) as a young adult may result in higher blood pressure (BP) and left ventricle mass index, resulting in changes to the heart structure, researchers report in the American Heart Association’s (AHA) journal Circulation.
The study is the first to assess if higher BMI can adversely impact the cardiovascular system of young adults.
The researchers, led by Kaitlin H. Wade, PhD, of the University of Bristol in the U.K., used three different analytic approaches with differing key sources of bias: conventional multivariable regression, Mendelian randomization (MR) and Recall-by-Genotype (RbG) to estimate the impact BMI has on cardiovascular health in approximately 14,000 healthy 17- to 20-year-old participants from the Avon Longitudinal Study of Parents and Children. Both MR and RbG utilize properties of genetic variation, and specifically, RbG utilizes the random allocation of genes at conception.
“While observational studies can suggest associations between risk factors or lifestyle behaviors and heart disease, they cannot prove cause-and-effect,” noted a prepared statement issued by the AHA. “Here, investigators triangulated findings from three different types of genetic analysis to uncover evidence that BMI causes specific differences in cardiovascular measurements.”
Both MR and RbG analyses found higher BMI causes higher systolic and diastolic blood pressure readings and also causes enlargement of left ventricle in young adults.
RbG results also found a causal role of higher BMI on higher stroke volume and cardiac output—but there was no significant evidence for a causal role on systemic vascular resistance or total arterial compliance.
“Thickening of vessel walls is widely considered to be the first sign of atherosclerosis, a disease in which fatty plaques build up within the arteries and lead to heart disease,” Wade said. “However, our findings suggest that higher BMIs cause changes in the heart structure of the young that may precede changes in blood vessels.”
The researchers noted their results support efforts to reduce BMI within a healthy range, starting at a young age to prevent heart disease later in life.
As a senior news writer for TriMed, Subrata covers cardiology, clinical innovation and healthcare business. She has a master’s degree in communication management and 12 years of experience in journalism and public relations.