Abdominal obesity and the spectrum of global cardiometabolic risks in US adults

Objective: To compare the association of obesity and abdominal obesity with cardiometabolic risk factor burden and global estimated coronary heart disease (CHD) risk among multiethnic US adults. Design: Cross-sectional, survey study. Subjects: A total of 4456 participants (representing 194.9 million adults) aged 20-79 years in the 2003-2004 National Health and Nutrition Examination Survey (NHANES). Measurements: Body mass index (BMI) and waist circumference (WC) measures, CHD risk factors and a 10-year estimated CHD risk based on Framingham algorithms. Obesity was defined as a BMI >= 30 kg/m(2) and abdominal obesity as a WC >88cm in women and >102cm in men. High CHD risk status included diabetes, cardiovascular disease (CVD) or a 10-year Framingham risk score of >20%. Results: Overall, abdominal obesity was present in 42.3% of men and 62.5% of women and in 53.6% of whites, 56.9% of blacks and 50.5% of Hispanics (P<0.001 between gender and ethnicity). However, using International Diabetes Federation (IDF)-recommended WC cut points for Hispanics, the prevalence of abdominal obesity was 78.3%. Mean levels of low-density lipoprotein cholesterol (LDL-C), systolic and diastolic blood pressure, fasting glucose and C-reactive protein increased, and high-density lipoprotein cholesterol (HDL-C) decreased (P<0.001) according to BMI and WC categories, although these associations were attenuated in blacks for blood pressure, LDL-C, HDL-C and triglycerides. Of those with high WC, 25-35% had >= 3 cardiometabolic risk factors. High CHD risk among those with high WC was most common in men (27.9%) and non-Hispanic whites (23.9%). Persons with a high vs normal WC, adjusted for age, gender, ethnicity and BMI were more likely to have >= 3 cardiometabolic risk factors (odds ratio (OR) 5.1, 95% confidence interval (CI) 3.9-6.6) and were classified as high CHD risk (OR 1.5, 95% CI 1.1-2.0). Conclusion: The association of abdominal obesity with risk factors varies by ethnicity and is independently associated with high CHD risk status, further validating its clinical significance.