Can insulin resistance exist as a primary defect in noninsulin-dependent diabetes mellitus?
In this study we have attempted to quantify the plasma insulin response to glucose and insulin action in 22 nonobese subjects: 11 with normal glucose tolerance and 11 with mild [mean fasting plasma glucose concentration, 128 +/- (+/- SEM) 5 mg/dL] noninsulin-dependent diabetes mellitus (NIDDM). Estimates of the plasma insulin response were made by determining the plasma insulin concentration at hourly intervals from 0800-1600 h, before and after mixed meals consumed at 0800 h (breakfast) and 1200 h (lunch). Insulin action was assessed by measuring glucose uptake during insulin clamp studies performed at steady state plasma insulin levels of approximately 10 and 60 microU/mL, with the difference between the 2 values defined as insulin-stimulated glucose uptake. Plasma glucose (P less than 0.001) and insulin (P less than 0.001) concentrations were significantly higher in patients with NIDDM throughout the 8-h period (by two-way analysis of variance). However, mean (+/- SEM) insulin-stimulated glucose uptake was markedly reduced (P less than 0.001) in patients with type 2 diabetes mellitus (112 +/- 72 vs. 336 +/- 44 mg/m2 min-1). Thus, patients with NIDDM and mild fasting hyperglycemia were both insulin resistant and hyperinsulinemic compared to normal individuals. These data indicate that a defect in insulin-stimulated glucose uptake can occur in NIDDM in the absence of significant hyperglycemia and/or hypoinsulinemia.
D000368:Aged; D001786:Blood Glucose / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism*; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008297:Male; D008875:Middle Aged
D001786:Blood Glucose; D007328:Insulin