Study challenges concept of 'healthy' obesity

Obese individuals who have no signs of cardiovascular disease show a much higher prevalence of early plaque buildup in the arteries compared to healthy normal weight individuals, according to a study published today in the Journal of the American College of Cardiology. The study challenges the idea of "healthy" obesity, and researchers recommend all obese individuals be counseled about their risks for cardiovascular disease and receive tips for achieving a healthy weight.

Obesity can often lead to cardiovascular disease through the development of dyslipidemia (abnormal amounts of fat or cholesterol in the blood), hyperglycemia (high blood sugar) and hypertension (high blood pressure)—all common conditions in obese individuals. But, the idea of "healthy" obese, individuals whose body weight puts them in the obese category but they show no signs of cardiovascular disease, is controversial.

Researchers in this study looked at 14, 828 metabolically healthy Korean adults aged 30 to 59 years who had no known cardiovascular disease and had undergone a health checkup including cardiac tomography estimation of coronary artery calcium scores, which is a measure of calcium build up in the plaque on artery walls. CAC scoring can determine early stage heart disease, such as atherosclerosis, before symptoms are present. Obesity or normal weight was determined using a standard Asian body mass index scale.

Based on CAC scores, obese individuals were found to have a much higher prevalence of subclinical coronary atherosclerosis, or early-stage plaque buildup in the arteries, than their normal weight counterparts. Atherosclerosis, if not managed, can lead to heart attack and sudden cardiac death, among other cardiovascular conditions.

"Obese individuals who are considered 'healthy' because they don't currently have heart disease risk factors, should not be assumed healthy by their doctors," said Yoosoo Chang, MD, lead author of the study and professor at Kangbuk Samsung Hospital Total Healthcare Center Center for Cohort Studies in Seoul, Korea. "Our research shows that the presence of obesity is enough to increase a person's risk of future heart disease and that the disease may already be starting to form in their body. It's important that these people learn this while they still have time to change their diet and exercise habits to prevent a future cardiovascular event."