Obese African Americans: the prevalence of dyslipidemia, hypertension, and diabetes mellitus.

CONTEXT

The prevalence of the cardiovascular disease risk factors, dyslipidemia, hypertension, and diabetes mellitus, is increased in the setting of obesity.

OBJECTIVE

To determine whether the prevalence of these risk factors increases with increasing body mass index in an obese cohort, or whether there is a threshold for their appearance.

DESIGN AND SETTING

Individuals with body mass index > or = 30 kg/m2 joined a weight reduction program in the Howard University General Clinical Research Center.

PARTICIPANTS

Five hundred fifteen African Americans (aged 12-74 years, mean body mass index of 42.8 +/- 8.5 kg/m2).

OUTCOME MEASURES

The cohort was divided by incremental increases in body mass index of 4.99 kg/m2, and the prevalence rates of hypertension (blood pressure > or = 140/90 mm Hg), dyslipidemia (total cholesterol > 200 mg/dL, or low-density lipoprotein > 130 mg/dL, or elevated ratio of total or low-density to high-density lipoprotein cholesterol) and diabetes mellitus (fasting blood glucose > or = 126 mg/dL or random blood glucose > 200 mg/dL) were determined for each group.

RESULTS

The cohort prevalence rates were: dyslipidemia, 27.0%; hypertension, 56.9%; and diabetes mellitus, 24.1%. These rates are higher than those found in the African-American population by the third National Health and Nutrition Examination Survey. After adjusting for age and sex, there were no significant differences in the prevalence rates of these risk factors according to increasing body mass index, suggesting a threshold of between 30 kg/m2-34.99 kg/m2 for maximal appearance of these risk factors.

CONCLUSION

The incidence rates of dyslipidemia, hypertension, and diabetes mellitus do not increase with a greater degree of obesity above a body mass index of 34.99 kg/m2.