Relationship between several surrogate estimates of insulin sensitivity in non-diabetic patients with coronary artery disease.

Background And Purpose: Insulin resistance plays an important role in the pathogenesis of coronary artery disease (CAD). Thus, there is a need for accurate and accessible tools for measurement of insulin sensitivity in patients with this disease. This study explored the relationship between several surrogate estimates of insulin sensitivity in non-diabetic patients with angiographic evidence of CAD.

Methods: The study population consisted of 1363 non-diabetic subjects with angiography results which revealed evidence of CAD in 660 and no evidence of CAD in 703 subjects. After overnight fasting, blood samples were drawn for determination of glucose and insulin concentrations in order to determine the homeostasis model assessment for insulin resistance (HOMA-IR) and the quantitative insulin sensitivity check index (QUICKI). In addition, steady-state plasma glucose (SSPG) concentrations obtained from insulin suppression tests were carried out in 54 subjects with and 194 subjects without CAD. The correlation of QUICKI with other surrogate estimates of insulin sensitivity in obese and non-obese subjects was also evaluated.

Results: The QUICKI correlated significantly with other methods for estimating insulin sensitivity in the CAD and non-CAD groups. The QUICKI also had a closer correlation with SSPG and log fasting plasma insulin (log FPI) in subjects with CAD (r = -0.573 and -0.869, respectively) than HOMA-IR (r = 0.508 and 0.777, respectively). QUICKI had a closer correlation with SSPG in the obese subjects than in the non-obese subjects, irrespective of the presence of CAD.

Conclusions: The QUICKI was more closely related with SSPG, insulin area, and log FPI than other measurements of insulin sensitivity. These findings suggest that the QUICKI may provide a convenient, efficient method to measure insulin sensitivity in non-diabetic patients with CAD.