Multiethnic Study: Obesity Linked to CVD Risk

Obesity is epidemic in most but not all racial and ethnic groups, and the incidence of cardiovascular disease risk factors and subclinical vascular disease is directly related to obesity regardless of race or ethnicity, according to recent findings.

The Multi-Ethnic Study of Atherosclerosis (MESA) is an observational cohort study that compared 6,814 white, African American, Hispanic, and Chinese American individuals aged 45-84 years who were free of clinical cardiovascular disease (CVD) at study baseline, 2000-2002 (Arch. Intern. Med. 2008;168:928-35).

The investigators compared CVD risk factors for each gender and racial or ethnic group across three BMI groups: normal (less than 25 kg/m2), overweight (25-29.9 kg/m2), and obese (30 kg/m2 or greater), and observed "striking differences" across racial/ethnic groups, they wrote.

At least 75% of the African American, Hispanic, and white male participants were overweight, as were more than 60% of the white women. Obesity was observed in more than 50% of the African American women, more than 40% of the Hispanic women, 30% of the African American and Hispanic men, and nearly 30% of the white men and women. In contrast, only one-third of the Chinese American men and women in the study were overweight, and only 5% were obese.

Obesity was associated with a greater risk of subclinical CVD markers across body-size groups, after adjustment for race, gender, age, and risk factors. Increased body size was significantly associated with a 1.2-fold greater prevalence of coronary artery calcium in the obese group, compared with the normal body-size group, and the association persisted after adjustment for traditional risk factors.

In another example, compared with normal body size, obese participants had a 32% increased risk of the intimal medial thickness of the internal carotid artery exceeding the 80th percentile, a 45% increased risk of the common carotid artery IMT exceeding the 80th percentile, and a more than twofold greater risk of left ventricular mass exceeding the 80th percentile--all of which also persisted after adjustment for traditional CVD risk factors.