A comparison of 3 methods for assessing insulin sensitivity in subjects with normal and abnormal glucose tolerance

The euglycaemic clamp, insulin sensitivity test with somatostatin, and insulin sensitivity test without somatostatin, were compared as in vivo methods of assessing insulin sensitivity. Fifteen subjects with varying degrees of glucose tolerance were studied. Somatostatin was not found to influence the assessment of insulin sensitivity by the insulin sensitivity test. When glucose disposal was expressed as metabolic clearance rate significant strong correlations were found between the euglycaemic clamp technique and the insulin sensitivity test with (r = 0.90) and without (r = 0.83) somatostatin. The effects of the tests on intermediary metabolism were also similar, and all 3 tests showed a similar impairment of insulin sensitivity in subjects with abnormal glucose tolerance. The insulin sensitivity test without somatostatin thus provides a simple and economical tool for studying insulin sensitivity.