Comparison of insulin sensitivity tests across a range of glucose tolerance from normal to diabetes

Abstract

Impaired glucose tolerance (IGT) and Type II (noninsulin-dependent) diabetes mellitus result from different contributions of deficient insulin secretion and impaired insulin sensitivity [1±8]. Routine quantification of these abnormalities is rarely done as simple, user friendly methods have not been validated or received general approval [9,10]. The choice of therapy might depend on the causative pathophysiology in a patient and, with the prospect of insulin-sensitising drugs as well as life-style changes to improve insulin sensitivity, routine assessment of insulin sensitivity might become more appropriate than at present [11, Diabetologia (1999) AbstractAims/hypothesis. Adequate comparison of the relative performance of insulin sensitivity tests is not yet available. We compared the discrimination of four insulin sensitivity tests, commonly used in vivo, across a range of glucose tolerance. Methods. Normal (n = 7), impaired glucose tolerant (n = 8) and Type II (non-insulin-dependent) diabetic subjects (n = 9) had in random order two tests from the following: frequently sampled insulin-modified intravenous glucose tolerance test (FSIVGTT-MinMod); homeostasis model assessment (HOMA) and 2-h continuous infusion of glucose with model assessment (CIGMA) with immunoreactive or specific insulin; short insulin tolerance tests (ITT). The discriminatory power of tests was assessed by the ratio of the within-subject standard deviation to the underlying between-subject standard deviation (discriminant ratio ± DR). The degree to which tests measured the same variable was assessed by comparing rank correlation with the maximum expected correlation given the imprecision of the tests. The unbiased lines of equivalence taking into account the precision of tests were constructed.Results. Reciprocal fasting plasma insulin (FPI ±1 ), HOMA %S and 2-h CIGMA %S, had similar DRs with ITT being less informative. The FSIVGTT-MinMod analysis was able to assess 13 out of 24 subjects and had a performance similar to ITT. Using specific rather than immunoreactive insulin for HOMA-CIG-MA did not improve the DR. Reciprocal fasting plasma insulin FPI ±1 , HOMA %S, 2-h CIGMA %S and S I FSIVGTT intercorrelated more than 90 % of the expected rank correlation given the imprecision of the tests, but ITT gave only limited correlation. Conclusion/interpretation. The HOMA-CIGMA test with immunoreactive insulin provides similar information in distinguishing insulin sensitivity between subjects with normal glucose tolerance, those with impaired glucose tolerance and those with Type II diabetes as does FSIVGTT, whereas ITT is less informative. [Diabetologia (1999) 42: 678±687]

Insulin resistance and impaired glucose tolerance in obese children and adolescents referred to a tertiary-care center in Israel

“…The QUICKI correlated with metabolic manifestations of insulin resistance and was able to Insulin resistance in obese children and adolescents S Shalitin et al discriminate increases in insulin resistance among diabetic patients, patients with IGT, and healthy persons. 27 IGF was found in only two of our patients with IGT, suggesting that fasting hyperglycemia is indicative of a more advanced stage of impaired glucose metabolism. Thus, neither fasting blood glucose nor insulin resistance indexes served as effective screening tools.…”

The central issue? Visceral fat mass is a good marker of insulin resistance and metabolic disturbance in women with polycystic ovary syndrome

“…Insulin (Immulite Ò ; DPC, Los Angeles, CA, USA): Insulin resistance was estimated by homeostasis model assessment (HOMA), a computerised model of the physiological loop which controls the concentration of blood glucose. [7][8][9] It allows an estimation of insulin resistance from the fasting levels of insulin and blood glucose. The insulin assay cross reacts at <1% with proinsulin.…”

An insulin-like growth factor-I gene polymorphism modifies the risk of microalbuminuria in subjects with an abnormal glucose tolerance

“…All individuals meeting criteria for diabetes or prediabetes were to be considered as subjects with an abnormal glucose tolerance (AGT). To determine insulin sensitivity we used the homeostasis model assessment (HOMA) (23).…”