Factor analysis has previously identified four independent factors that characterize the insulin resistance syndrome in women, interpreted as 1) weight/waist, 2) lipids, 3) insulin/glucose, and 4) systolic and diastolic blood pressure. Because it is not known whether similar factors emerge for men, or for diabetics, factor analysis was used to investigate the clustering of features characterizing the insulin resistance syndrome using data from 3,159 elderly (71-93 years) Japanese-American men participating in the fourth examination of the Honolulu Heart Program during 1991-1993. Consistent with previous results, factor analysis reduced eight risk factors (insulin, glucose, systolic blood pressure, diastolic blood pressure, triglycerides, high-density lipoprotein cholesterol, weight, and waist circumference) to four uncorrelated factors that explained 78.2% and 74.7% of the variance in nondiabetics (n = 2,760) and diabetics (n = 399), respectively. These factors were interpreted as 1) weight/waist, 2) blood pressure, 3) lipids, and 4) insulin/glucose. Modest differences in the associations between fasting insulin and factors 1, 3, and 4 were noted for diabetics. These consistently identified composite factors may represent markers for underlying pathophysiologic mechanisms of the insulin resistance syndrome and risk of non-insulin-dependent diabetes mellitus.