Insulin Sensitivity and Its Measurement: Structural Commonalities among the Methods

Abstract

Insulin is the principal hormone of metabolic regulation. Reduced responses to insulin constitute an underlying feature of type 2 diabetes. It is, therefore, incumbent on those who work in this area (as well as many others) to characterize this response, in as simple and consistent a way as possible, so that this measure can be used both in the investigational and clinical setting. This type of approach, although eminently useful, is necessarily an oversimplification. Not only does insulin sensitivity change in pathological situations, but also in normal physiology. Tissue-specific, metabolite-specific, as well as process-specific responses may be expected to occur. Variations also occur in time-depending on the physiological state of the individual (e.g. pregnancy, aging) or following diurnal rhythms. It is perhaps remarkable that any consistent assessment of overall insulin sensitivity can be made. The observation that this can often be achieved has led to hypotheses suggesting that sensitivity to insulin is primarily determined at a single site (tissue, metabolite). At the same time, there are many discussions about the inconsistencies inherent in different approaches to the measurement of this parameter, suggesting that some of these variants, metabolic or otherwise, could lead to the low correlation between methods sometimes seen. Nevertheless, most methods used in the assessment of insulin sensitivity examine the response to insulin of a single metabolite, glucose, primarily in the muscle and liver, and under fasting conditions and should, therefore, demonstrate insulin sensitivity that is comparable among methods.

Pubertal alterations in growth and body composition. VI. Pubertal insulin resistance: relation to adiposity, body fat distribution and hormone release

“…Fasting serum insulin concentrations were greater in the late-pubertal group, while fasting serum glucose concentrations were not different between pubertal maturation groups, which also suggests pubertal insulin resistance (Table 2). Although insulin resistance is best measured by the euglycemic clamp technique, the HOMA model 26,33 and fasting insulin concentrations 2,17,34,35 adequately parallel insulin resistance measures. However, HOMA values and fasting serum insulin concentrations were highly related (r ¼ 0.92, P < 0.001) and HOMA may provide little information beyond fasting serum insulin concentrations.…”

Oral supplementation of magnesium aspartate hydrochloride in horses with Equine Metabolic Syndrome

“…Im Vergleich hierzu sind der FSGITT (Frequently Sampled Glucose Insulin Tolerance Test) und die EHC (Euglycaemic Hyperinsulinaemic Clamp) Technik präziser, aber auch deutlich aufwendiger und werden daher in der Praxis nicht routinemäßig eingesetzt (Knowles et al 2012). Bei ersterem werden die Blutproben zur Glukose-und Insulinbestimmung in sehr kurzen Abständen entnommen und anschließend mit einer speziellen Software mit Hilfe der Minimal Model Analyse ausgewertet (Radziuk 2000). Bei der EHC Technik bekommen die Patienten eine Dauertropfinfusion mit Insulin und aus der Menge der Glukose, die benötigt wird um den Glukosespiegel stabil zu halten, wird die Insulinsensitivität berechnet.…”

Heritability of model-derived parameters of beta cell secretion during intravenous and oral glucose tolerance tests: a study of twins

“…In the glucose-insulin system, the gold standard for measuring insulin sensitivity is the euglycaemic-hyperinsulinaemic clamp [2], to which other measures of insulin sensitivity are compared [3]. Furthermore, the physiological meaning of clamp-measured insulin sensitivity, i.e.…”