Being overweight may change young adults’ heart structure, function
Circulation Journal Report
- Being overweight may cause higher blood pressure and changes to the heart’s structure, even in young adults.
- Efforts to achieve or maintain a normal weight from a young age may help to prevent the development of heart disease later in life.
- The innovative study design used a new genetic analysis to assess if weight directly causes higher blood pressure and changes in heart’s structure.
Embargoed until 4 a.m. CT / 5 a.m. ET Monday, July 30, 2018
DALLAS, July 30, 2018 — Even as a young adult, being overweight may cause higher blood pressure and thicken heart muscle, setting the stage for heart disease later in life, according to new research in the American Heart Association’s journal Circulation.
The study is the first to explore if higher body mass index (BMI) – a weight-for-height index – results in adverse effects on the cardiovascular system in young adults.
While observational studies can suggest associations between risk factors or lifestyle behaviors and heart disease, they cannot prove cause-and-effect. Here, investigators triangulated findings from three different types of genetic analysis to uncover evidence that BMI causes specific differences in cardiovascular measurements.
“Our results support efforts to reduce body mass index to within a normal, healthy range from a young age to prevent later heart disease,” said Kaitlin H. Wade, B.Sc., Ph.D., lead author of the study and a research associate at the Medical Research Council Integrative Epidemiology Unit at the University of Bristol Medical School in the United Kingdom.
Researchers used data on several thousand healthy 17-year-olds and 21-year-olds who have participated in the ongoing Children of the 90s study (also known as the Avon Longitudinal Study of Parents and Children) since they were born in the Bristol area of the United Kingdom.
The researchers’ findings suggest that higher BMI:
- caused higher systolic (top number) and diastolic (bottom number) blood pressure; and
- caused enlargement of the left ventricle, the heart’s main pumping chamber.
“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. However, our findings suggest that higher BMIs cause changes in the heart structure of the young that may precede changes in blood vessels,” Wade said.
Two of the analyses used in the study (Mendelian randomization and recall-by-genotype) take advantage of the properties of genetic variation. Recall-by-genotype is novel and exploits the random allocation of genes at conception.
“At a population level, this provides a natural experiment analogous to a randomized trial where we can compare differences in an outcome (such as heart structure and function) with differences in BMI, without the relationship being skewed by other lifestyle and behavioral factors,” Wade said.
Most participants in the longitudinal studies were white, limiting the generalizability of the findings to other ethnic groups.
The researchers plan to investigate the relationship between higher BMI and other possible disease mechanisms, such as the abundance and diversity of microbes living in the gut. They also hope to explore the relationship between BMI and cardiac structure and function in a population now in their 70s.
Co-authors are Scott T. Chiesa, Ph.D.; Alun D. Hughes, Ph.D.; Nish Chaturvedi, M.D.; Marietta Charakida, M.D.; Alicja Rapala, B.A.; Vivek Muthurangu, M.D.; Tauseef Khan, Ph.D.; Nicholas Finer, M.B., B.S.; Naveed Sattar, M.D., Ph.D.; Laura D. Howe, M.Sc., Ph.D.; Abigail Fraser, M.P.H., Ph.D.; Debbie A. Lawlor, Ph.D.; George Davey Smith, M.D., D.Sc.; John E. Deanfield, B.Ch.MB; and Nicholas J. Timpson, Ph.D. The authors reported no disclosures.
The Wellcome Trust, Medical Research Council, and British Heart Foundation funded the study.
- Available multimedia is on the right column of the release link - https://newsroom.heart.org/news/being-overweight-may-change-young-adults-heart-structure-function?preview=f9b651c9e9067fa9e7dfd35950e8da77
- After July 30, view the manuscript online.
- Learn more about High Blood Pressure
- Follow AHA/ASA news on Twitter @HeartNews
- For updates and new science from the Circulation journal follow @CircAHA
Statements and conclusions of study authors published in American Heart Association scientific journals are solely those of the study authors and do not necessarily reflect the association’s policy or position. The association makes no representation or guarantee as to their accuracy or reliability. The association receives funding primarily from individuals; foundations and corporations (including pharmaceutical, device manufacturers and other companies) also make donations and fund specific association programs and events. The association has strict policies to prevent these relationships from influencing the science content. Revenues from pharmaceutical and device corporations and health insurance providers are available at www.heart.org/corporatefunding.
About the American Heart Association
The American Heart Association is devoted to saving people from heart disease and stroke – the two leading causes of death in the world. We team with millions of volunteers to fund innovative research, fight for stronger public health policies and provide lifesaving tools and information to prevent and treat these diseases. The Dallas-based association is the nation’s oldest and largest voluntary organization dedicated to fighting heart disease and stroke. To learn more or to get involved, call 1-800-AHA-USA1, visit heart.org or call any of our offices around the country. Follow us on Facebook and Twitter.
For Media Inquiries and AHA/ASA Spokesperson Perspective: 214-706-1173
Bridgette McNeill: 214-706-1135; firstname.lastname@example.org
For Public Inquiries: 1-800-AHA-USA1 (242-8721)