Insulin sensitivity indexes from a single sample in nonobese Japanese type 2 diabetic patients: comparison with minimal model analysis.

Insulin resistance is important not only in obesity and diabetes but also in essential hypertension, dyslipidemia, and atherosclerotic cardiovascular disease (1). We recently demonstrated that the homeostasis model assessment for insulin resistance (HOMA-IR) proposed by Matthews et al. (2) is validated against the minimal model–derived insulin sensitivity index (MINMOD-SI) in type 2 diabetic patients (3). Although the relationship between HOMA-IR and MINIMOD-SI in these patients was statistically significant, the correlation coefficient was low ( r = 0.459, P = 0.021) (3). Therefore, a more highly correlated simple index is needed to measure insulin resistance in large type 2 diabetic populations. The major drawback of HOMA-IR is that when the glucose or insulin concentration increases, the value is overestimated. Furthermore, HOMA-IR is not linear over wide ranges of insulin sensitivity in man (4). Katz et al. (5) recently proposed the quantitative insulin sensitivity check …