Editing Insulin resistance (section)

===Hyperinsulinemic euglycemic clamp===
The [[gold standard (test)|gold standard]] for investigating and quantifying insulin resistance is the "hyperinsulinemic euglycemic clamp," so-called because it measures the amount of [[glucose]] necessary to compensate for an increased [[insulin]] level without causing [[hypoglycemia]].<ref name = Anders_1979>{{cite journal | vauthors = DeFronzo RA, Tobin JD, Andres R | title = Glucose clamp technique: a method for quantifying insulin secretion and resistance | journal = The American Journal of Physiology | volume = 237 | issue = 3 | pages = E214-23 | date = September 1979 | pmid = 382871 | doi = 10.1152/ajpendo.1979.237.3.e214 | s2cid = 7192984 }}</ref> It is a type of [[glucose clamp technique]]. The test is rarely performed in clinical care, but is used in medical research, for example, to assess the effects of different medications. The rate of glucose infusion commonly is referred to in diabetes literature as the GINF value.<ref name="Muniyappa">{{cite journal | vauthors = Muniyappa R, Lee S, Chen H, Quon MJ | title = Current approaches for assessing insulin sensitivity and resistance in vivo: advantages, limitations, and appropriate usage | journal = American Journal of Physiology. Endocrinology and Metabolism | volume = 294 | issue = 1 | pages = E15-26 | date = January 2008 | pmid = 17957034 | doi = 10.1152/ajpendo.00645.2007 | s2cid = 848540 }}</ref>

The procedure takes about two hours. Through a [[peripheral vein]], [[insulin]] is infused at 10–120 mU per m<sup>2</sup> per [[minute]]. In order to compensate for the insulin [[intravenous|infusion]], [[glucose]] 20% is infused to maintain blood sugar levels between 5 and 5.5&nbsp;mmol/L. The rate of glucose infusion is determined by checking the [[blood sugar]] levels every five to ten minutes.<ref name="Muniyappa" />

The insulin sensitivity is determined by the rate of glucose infusion during the last thirty minutes of the test. If high levels (7.5&nbsp;mg/min or higher) are needed, the patient is considered insulin-sensitive. Conversely, very low levels (4.0&nbsp;mg/min or lower) indicate insulin resistance. Levels falling between 4.0 and 7.5&nbsp;mg/min are not conclusive and suggest "impaired glucose tolerance," which is an early indication of insulin resistance.<ref name="Muniyappa" />

This fundamental technique can be greatly enhanced through the utilization of glucose tracers. Glucose can be labeled with either stable or radioactive atoms. Commonly employed tracers include 3-3H glucose (radioactive), 6,6 2H-glucose (stable), and 1-13C glucose (stable). Prior to initiating the hyperinsulinemic phase, a 3-hour tracer infusion allows for the determination of the basal rate of glucose production. Throughout the clamp, the plasma tracer concentrations facilitate the computation of whole-body insulin-stimulated glucose metabolism, as well as the production of glucose by the body. (i.e., endogenous glucose production).<ref name="Muniyappa" />