Just a few extra pounds during adolescence may translate into higher odds for heart disease in adulthood, a new study of young men suggests.
It included about 1.7 million Swedish men who began military service at ages 18 or 19 between 1969 and 2005. They were followed for up to 46 years.
Increased weight = increased risk
During the follow-up, nearly 4 500 were diagnosed with cardiomyopathy, an uncommon heart muscle condition that can lead to heart failure. Average age at diagnosis was 45.5 years.
Men who were lean as teens (body mass index, or BMI, below 20) had a low risk of cardiomyopathy. But risk steadily rose with increased weight, even among men who were on the high end of normal BMI (22.5 to 25) as teens.
BMI is an estimate of body fat based on weight and height. A BMI of 30 or more is considered obese: For example, a 5-foot-10-inch (177.8cm) man who weighs 209 pounds (94.8kg) has a BMI of 30.
There are several types of cardiomyopathy. In dilated cardiomyopathy, the heart muscle becomes weak and can't pump blood efficiently. In hypertrophic cardiomyopathy, it becomes stiff and the heart can't fill with blood properly.
No cause-and-effect link
Men who had a BMI of 35 and over in their teens were eight times more likely to develop dilated cardiomyopathy than those who were lean in their teens. Researchers weren't able to estimate the increased risk for hypertrophic cardiomyopathy because there were too few cases.
The study was published in the journal Circulation.
The findings likely apply to men worldwide, including those in the United States, study co-author Dr Annika Rosengren said in a journal news release. She is a cardiologist and professor of medicine at the University of Gothenburg in Sweden.
More study would be needed to learn if there are racial or ethnic differences in how weight affects cardiomyopathy risk, Rosengren said. The study only showed an association rather than a cause-and-effect link.
It's also unclear if the findings apply to women, Rosengren said.
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