High fasting plasma insulin is an indicator of coronary heart disease in non-insulin-dependent diabetic patients and nondiabetic subjects.

The association between fasting plasma insulin level and coronary heart disease (CHD) was studied in 909 non-insulin-dependent diabetic (NIDDM) patients, aged 45-64 years, and in 1,373 nondiabetic control subjects. Both diabetic and nondiabetic subjects with various manifestations of CHD had higher plasma insulin levels than did subjects free of CHD. By plasma insulin quintiles formed according to values in nondiabetic subjects, the age-adjusted prevalence of CHD defined by symptoms and/or electrocardiographic changes in diabetic men was 48.2% in quintiles I + II (lowest), 54.8% in quintiles III + IV, and 65.7% in quintile V (highest) (p = 0.006). The respective prevalences in diabetic women were 53.5%, 59.1%, and 73.3% (p = 0.004); in nondiabetic men, 28.1%, 33.7%, and 43.3%, respectively (p = 0.016); and in nondiabetic women, 28.1%, 34.9%, and 44.3%, respectively (p = 0.007). An essentially similar association was observed between plasma insulin level and definite or possible myocardial infarction (MI)....