Differences in Risk Factors for Coronary Heart Disease among Diabetic and Nondiabetic Individuals from a Population with High Rates of Diabetes: The Strong Heart Study

CONTEXT: Coronary heart disease (CHD) is the leading cause of death in the United States. OBJECTIVE: This study compares differences in risk factors for CHD in diabetic vs. nondiabetic Strong Heart Study participants. DESIGN: This was an observational study. SETTING: The study was conducted at three centers in Arizona, Oklahoma, and North and South Dakota. PARTICIPANTS: Data were obtained from 3563 of 4549 American Indians free of cardiovascular disease at baseline. INTERVENTION(S): CHD events were ascertained during follow-up. MAIN OUTCOME MEASURE: CHD events were classified using standardized criteria. RESULTS: In diabetic and nondiabetic participants, 545 and 216 CHD events, respectively, were ascertained during follow-up (21,194 and 22,990 person-years); age- and sex-adjusted incidence rates of CHD were higher for the diabetic group (27.5 vs. 12.1 per 1,000 person-years). Risk factors for incident CHD common to both groups included older age, male sex, prehypertension or hypertension, and elevated low-density lipoprotein cholesterol. Risk factors specific to the diabetic group were lower high-density lipoprotein cholesterol, current smoking, macroalbuminuria, lower estimated glomerular filtration rate, use of diabetes medication, and longer duration of diabetes. Higher body mass index was a risk factor only for the nondiabetic group. The association of male sex and CHD was greater in those without diabetes than in those with diabetes. CONCLUSIONS: In addition to higher incidence rates of CHD events in persons with diabetes compared with those without, the two groups differed in CHD risk factors. These differences must be recognized in estimating CHD risk and managing risk factors.