Limitation of the Homeostasis Model Assessment to Predict Insulin Resistance and β-Cell Dysfunction in Older People

Abstract

Context: Studies in older people have shown inconsistent agreement between homeostasis model assessment of insulin resistance (HOMA-IR) and dynamic measures of insulin action and have not evaluated HOMA ␤-cell. Objective:We compared measures of insulin sensitivity and ␤-cell function from the frequently sampled iv glucose tolerance test (FSIGT) to HOMA models.Design/Patients/Setting/Intervention: Two hundred fourteen young and old with normal glucose tolerance (NGT) and old with impaired glucose tolerance (IGT) participated in a retrospective analysis of FSIGT data in a university medical setting.Main Outcome Measure: Sensitivity to insulin (S I ) and acute insulin response to glucose (AIRg) from FSIGT were compared with HOMA models.Results: S I and HOMA-IR measures identified similar patterns of increasing insulin resistance in the two older groups, compared with younger people with NGT, with the greatest degree of insulin resistance in older people with IGT (P Ͻ 0.05 vs. young and old NGT for both S I and HOMA-IR). Agreement between HOMA-IR and S I was moderate (weighted kappa ϭ 0.51). AIRg was similar in young and old NGT but was markedly decreased in old IGT (P Ͻ 0.05 vs. young and old NGT). HOMA-␤-cell was similar in the three groups. Agreement between HOMA ␤-cell and AIRg was weak (weighted kappa ϭ 0.35).Conclusions: HOMA-IR may detect age-related insulin resistance when comparing large populations of older people. However, dynamic testing appears to be necessary to quantitate diminished insulin secretion in older people. (J Clin Endocrinol Metab 91: 629 -634, 2006)T HE PREVALENCE OF type 2 diabetes and impaired glucose tolerance (IGT) increases with age (1). Multiple risk factors for type 2 diabetes including obesity and decreased physical activity associated with aging likely predispose older people to develop glucose intolerance and increased insulin resistance. ␤-Cell dysfunction has been consistently demonstrated even with normal aging, with greater defects in older people with IGT (1, 2). Thus, availability of simple, accurate measures to quantify the degree of insulin resistance and impaired ␤-cell function in the older population would be of great value.The homeostasis model assessment (HOMA) is a commonly used method to assess insulin resistance and ␤-cell function and requires only fasting glucose and insulin levels.The HOMA model of insulin resistance (HOMA-IR) has been found to correlate with the hyperinsulinemic glucose clamp and the minimal model measures of insulin action and ␤-cell function, primarily in younger and middle-aged people with normal glucose tolerance (3-5) and smaller groups of middle-aged people with type 2 diabetes (3,5,6).Previous studies have suggested that HOMA-IR may not be a good predictor of insulin resistance when compared with the euglycemic clamp in older men with IGT (7) and older men and women with diabetes (8). Evaluation of HOMA measures of ␤-cell function in older people, particularly those with IGT, has not been performed. In the present study, we compared meas...

Acute glucose dysmetabolism in the early phase of ST-elevation myocardial infarction: the age response

“…Chang et al, 30 in a retrospective analysis, examined the HOMA model in comparison with dynamic testing of insulin sensitivity and β-cell function with the frequently sampled i.v. glucose tolerance test in a large cohort of both older men and women with normal and impaired glucose tolerance.…”

“…glucose tolerance test was moderate. The authors concluded that HOMA may detect age-related insulin resistance when comparing large populations of older people, though dynamic 30 However, the euglycaemic hyperinsulinaemic clamp is time consuming, labour intensive and requires an experienced operator to manage the technical difficulties, so it is known to be not appropriate for routine clinical applications. 31 On the other hand, the HOMA index, which reflects basal insulin sensitivity and responsiveness, has been recently used to estimate insulin resistance in critically ill patients with acute renal failure.…”

Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) in the Diagnosis of Insulin Resistance and Prediabetes

“…Some of the other studies have suggested that HOMA-IR test may have significant limitation in predicting insulin resistance and beta-cell dysfunction in older people. Chang A.M et al compared sensitivity to insulin (S(I)) and acute insulin response to glucose (AIRg) from FSIGT with HOMA models and concluded that there was a weak Agreement between HOMA beta-cell and AIR (16) . Another important factor while determining or studying HOMA-IR in patients is the different cutoff values in different population.…”

Acute glucose dysmetabolism in the elderly with ST elevation myocardial infarction submitted to mechanical revascularization

“…Chang et al [51] in a retrospective analysis, examined the HOMA model in comparison with dynamic testing of insulin sensitivity and β-cell function with the frequently sampled i.v. glucose tolerance test in a large cohort of both older men and women with normal and impaired glucose tolerance.…”