Study documents obesity and its association with heart risk

Obesity rates appear high in most but not all ethnic groups in the United States, and extra weight is associated with cardiovascular risk factors and markers of sub-clinical heart disease, according to a report in the May 12 issue of Archives of Internal Medicine, one of the JAMA/Archives journals. The United States, along with many other countries, is experiencing an epidemic of obesity, according to background information in the article. Between 1960 and 2000, rates of obesity increased from 11 percent to 28 percent in men and 16 percent to 34 percent in women. “The obesity epidemic has the potential to reduce further gains in the U.S. life expectancy, largely through an effect on cardiovascular disease mortality [death],” the authors write.

Gregory L. Burke, M.D., M.S., of Wake Forest University School of Medicine, Winston-Salem, N.C., and colleagues assessed data from the Multi-Ethnic Study of Atherosclerosis (MESA), which involved 6,814 individuals age 45 to 84 who did not have cardiovascular disease when the study began (2000 to 2002). Participants completed a standard questionnaire with information about demographics and health risk factors and also underwent testing for a variety of cardiovascular disease markers.

“A large proportion of white, African American and Hispanic participants were overweight (60 percent to 85 percent) and obese (30 percent to 50 percent), while fewer Chinese American participants were overweight (33 percent) or obese (5 percent),” the authors write. “A higher body mass index (BMI) was associated with more adverse levels of blood pressure, lipoproteins [cholesterol] and fasting glucose despite a higher prevalence of pharmacologic treatment.”

Obesity also was associated with the following risk factors for heart disease and stroke:

• A 17 percent greater risk of coronary artery calcium, which may be a marker of coronary artery disease
• A 45 percent greater risk of having artery walls thicker than the 80th percentile in the common carotid arteries, which is a marker for atherosclerosis
• A 2.7-fold greater risk of having a left ventricle (the lower chamber of the heart that pumps blood throughout the body) with a mass higher than the 80th percentile

“These data confirm the epidemic of obesity in most but not all racial and ethnic groups,” the authors conclude. “The observed low prevalence of obesity in Chinese American participants indicates that high rates of obesity should not be considered inevitable. These findings may be viewed as indicators of potential future increases in vascular disease burden and health care costs associated with the obesity epidemic.”

Source: JAMA and Archives Journals