Assessment of Insulin Resistance with the Insulin Suppression Test and the Euglycemic Clamp

Abstract

Insulin resistance was quantified with two different methods in 30 subjects with varying degrees of glucose tolerance. One method, the insulin suppression test, is performed by continuously infusing epinephrine, propranolol, insulin, and glucose. Epinephrine and propranolol suppress endogenous insulin release, and steady-state plasma levels of exogenous insulin and glucose are reached in all individuals. Because the steady-state insulin level is the same in all subjects, the height of the steady-state plasma glucose level provides a direct estimate of insulin resistance. The other method, the euglycemic clamp technique, produces a steady-state level of exogenous hyperinsulinemia by means of a primed and continuous insulin infusion. Glucose is also infused at a rate sufficient to prevent an insulin-induced fall in glucose concentration, and the amount of glucose required to maintain the basal plasma glucose level provides the estimates of insulin resistance. The results indicated that estimates of insulin resistance generated by the two methods were highly correlated (r = 0.93). Furthermore, both methods of assessing insulin resistance indicated that the greater the degree of glucose intolerance, the more severe the insulin resistance. These results serve to further emphasize the importance of insulin resistance in the pathogenesis of hyperglycemia in type II diabetes.

Insulin sensitivity in Chinese ovo-lactovegetarians compared with omnivores

“…SSPG correlates closely to the euglycemic insulin clamp (r ¼ 0.93) and is a simpler method (Greenfield et al, 1981).…”

“…The insulin suppression test (IST) provides another method to assess insulin action in vivo and is simpler (Reaven & Olefsky, 1977). Greenfield et al (1981) have demonstrated a close correlation between estimates of insulin sensitivity obtained from IST and from the euglycemic clamp. Yeni-Komshian et al (2000) used steady-state plasma glucose (SSPG) from the IST as the reference method.…”

Enhanced proportion of small adipose cells in insulin-resistant vs insulin-sensitive obese individuals implicates impaired adipogenesis

“…Quantitation of insulin-mediated glucose disposal Insulinmediated glucose disposal was quantified by a modification [19] of the IST as originally described and validated [20,21]. Briefly, subjects were infused for 180 min with octreotide (0.27 μg m −2 min −1 ) to suppress endogenous insulin secretion, insulin (25 mU m −2 min −1 ) and glucose (240 mg m −2 min −1 ).…”

Insulin resistance in young salt-sensitive normotensive subjects.

“…20 -24 However, the insulin response to an oral glucose load provides only a crude measure of insulin sensitivity. 25 In the present study, we therefore examined the relation between insulin sensitivity as measured by the "insulin suppression test" 26 - 27 and blood pressure sensitivity to salt intake in young, lean normotensive subjects. The insulin suppression test uses the intravenous infusion of a fixed combination of insulin and glucose during which endogenous insulin release is suppressed by the concomitant administration of somatostatin.…”