Early adult weight gain is linked to poor heart health later in life, study finds

According to research published in European Heart Journal today (Wednesday).

Scientists have discovered a link between weight gain in young and middle-aged adults and enlarged hearts that pump blood less well. This is over and above the effect of being overweight in later years.

The findings are based on a large study that tracked the health of all babies born in England, Scotland and Wales during one week in 1946.

The study was led by Alun Hughes, Professor of Cardiovascular Physiology and Pharmacology at UCL in London, UK. He said: “We know that being overweight is associated with poor heart health, but we know little about the long-term relationship between being overweight in adulthood and subsequent heart health. We wanted to examine whether being overweight earlier in adulthood showed lasting associations with worse heart health, regardless of people’s weight in later life.”

The researchers looked at data on 1,690 people taking part in the British Medical Research Council’s National Survey of Health and Development Birth Cohort. Throughout their adult lives, these people had their body mass index (BMI) and waist-to-hip ratio measured. They also underwent echocardiograms where ultrasound is used to investigate the structure and function of the heart.

The researchers were particularly interested in a measurement called left ventricular mass, because when it’s larger than expected, it indicates more heart tissue. This is a reliable indicator of poor heart health and increased risk of death from heart disease.

The data showed that people whose BMI was elevated at any time from age 20 onwards had a higher left ventricular mass in their 60s, even when the researchers took into account people’s BMIs in their 60s. For example, in an average 43-year-old, a five point higher BMI corresponded to an increase in left ventricular mass of 15% or 27 grams. “This suggests that weight gain, even at a young age, leads to heart damage beyond the effects of being overweight in later life,” Professor Hughes explained.

“Maintaining a healthy weight is likely to be important for people even in early adulthood, and if we want to improve heart health in the long term, we need to prevent weight gain in people of all ages. This means developing policies that reduce the current obesity epidemic.”

The researchers caution that the study included mostly white Europeans, so it may not apply to the global population.

Professor Hughes continued: ‘This type of study cannot prove conclusively that earlier weight gain causes heart damage, only that the two are closely linked. It also doesn’t tell us how the two are connected, but if the effects of excess weight on the heart are irreversible or only partially reversible, then we can expect to see heart damage that accumulates and worsens over a lifetime.

“This work could not have been carried out if researchers and funders had not taken a long-term view and supported research starting at birth and continuing throughout life,” added Professor Hughes.

The researchers will now study the role of diabetes and high blood sugar in explaining the link between weight gain and heart health. They also plan to study weight gain in childhood and adolescence in relation to heart health.

In an accompanying article, Professor Leonardo Roever from the Brazilian Evidence-Based Health Network, Uberlândia, Brazil, and colleagues write: “… this study poignantly summarizes the temporal and dimensional continuum of cardiac damage associated with with abnormal BMI and provides compelling evidence that overweight or obesity, even at an earlier age, translates into adverse cardiovascular risk profiles…”

They add: “…it is possible that improvements in BMI over several decades, such as in a patient who was obese when young but has now successfully lost weight through diet and exercise, may translate into significant clinical benefits from preventing or reversing cardiac injury or dysfunction’.