Prevalence and correlates of the insulin resistance syndrome among Native Americans - The Inter-Tribal Heart Project

OBJECTIVE - The clustering of factors characterizing the insulin resistance syndrome has not been assessed among Native Americans, a population at hig h risk for diabetes and cardiovascular disease. We examined the distributio n and correlates of the insulin resistance syndrome among individuals in th ree Chippewa and Menominee communities in Wisconsin and Minnesota. RESEARCH DESIGN AND METHODS - Cross-sectional data from 488 men and 822 wom en ages greater than or equal to 25 years in the Inter-Tribal Heart Project (1992-1994) were included. The clustering of each individual trait (hypert ension, diabetes, high triglycerides, and low HDL cholesterol) with the oth er traits and the association of the number of traits with measures of adip osity and insulin levels were examined. RESULTS - Among the men, 40.4, 32.6, 17.4, and 9.6% had none, one, two, or at least three of the four traits, respectively, among the women, the respe ctive percentages were 53.2, 25.6, 15.3, and 6.0%. The percentage of indivi duals with each particular trait significantly increased (P < 0.01) among t hose with none, one, or at least two other syndrome traits. Having more syn drome traits was significantly related (P < 0.001) to higher BMI, conicity index, waist circumference, and waist-to-hip and waist-to-thigh ratios. Amo ng individuals with normal glucose levels, having more syndrome traits was significantly related (P less than or equal to 0.05) to higher fasting insu lin levels after adjusting for age and measures of adiposity, although asso ciations were attenuated with adjustment for either BMI or waist circumfere nce. CONCLUSIONS - Traits characterizing the insulin resistance syndrome were fo und to be clustered to a significant degree among Native Americans in this study Comprehensive public health efforts are needed to reduce adverse leve ls of these risk factors in this high-risk population.