Long-term obesity increases the risk of heart disease
Young adults who remain obese for two decades or more double their risk of developing a marker of heart disease in middle age, a study found.
Every year of obesity raises the risk of developing coronary artery calcification, a silent predictor of heart disease with mild to no symptoms, by two to four per cent, according to research in the Journal of the American Medical Association.
The study is the first to show that how long a person is obese can independently contribute to heart risk, said Jared Reis, the lead study author and an epidemiologist at the National Heart, Lung, and Blood Institute, which is part of the National Institutes of Health (NIH) and based in Bethesda, Md.
“What our study suggests is if we’re measuring only body mass index and waist circumference, we may be underestimating the health risks of obesity by not measuring the duration,” Reis said in a telephone interview.
Researchers looked at 3,275 adults aged 18 to 30 who weren’t obese at the beginning of the study in the mid-1980s. Those in the study were given computed tomography scans to detect coronary artery calcification over 25 years. Their obesity and abdominal obesity also was measured.
The researchers found that about 38 per cent of those who were obese for more than 20 years and 39 per cent of those who had abdominal obesity for that time developed coronary artery calcification, compared with 25 per cent of those who never became obese and never developed abdominal obesity.
Those in the study who had obesity and abdominal obesity over two decades or more also had coronary artery calcification progress in their heart.
Obesity is measured using body mass index, or BMI, a calculation of weight and height. For example, a 5-foot-4-inch woman weighing 80 kilograms has a BMI of 30. A BMI of 30 or more is considered obese, while a BMI of 25 to 29.9 is considered overweight, according to the NIH.