Relation of generalized and central obesity to cardiovascular risk factorsand prevalent coronary heart disease in a sample of American Indians: the Strong Heart Study

OBJECTIVE: To examine the hypothesis linking measures of obesity including body mass index (BMI), waist circumference (waist) and percentage body fat to coronary heart disease (CHD) prevalence and its risk factors in American Indians. DESIGN: The Strong Heart Study assesses the prevalence of CHD and its risk factors in American Indians in Arizona, Oklahoma and South/North Dakota. Pa rticipants underwent a physical examination and an electrocardiogram; anthr opometric and blood pressure measurements were taken, as were measurements of glucose, lipoproteins, fibrinogen, insulin, hemoglobin A(1c) and urinary albumin. PARTICIPANTS: Data were available for 4549 men and women between 45 and 74y of age. MEASUREMENTS: Obesity, measured using body mass index, waist circumference and percentage body fat, was correlated with prevalent CHD and its risk fac tors. RESULTS: More than 75% of participants were overweight (BMI > 25 kg/m(2)). Measures of obesity were greater in women than in men, in younger than in o lder participants, and in participants with diabetes than in nondiabetic pa rticipants. CHD risk factors were associated with measures of obesity but, except for insulin concentration, changes in metabolic variables with incre asing obesity were small. Associations were not stronger with waist than wi th BMI. The prevalence of CHD in those whose BMI and/or waist measurements lay in the lowest and highest quintiles, by gender and diabetic status, was similar. CONCLUSIONS: Although CHD risk factors are associated with obesity in Ameri can Indians, distribution of obesity (ie waist) is no more closely related to risk factors than is generalized obesity (ie BMI), and changes in CHD ri sk factors with obesity were small. Thus, the relations among obesity, body fat distribution and CHD risk may differ in this population.