Phenotypic characterization of insulin-resistant and insulin-sensitive obesity

Abstract

Context: Whereas insulin resistance and obesity coexist, some obese individuals remain insulin sensitive. Objective: We examined phenotypic and metabolic factors associated with insulin sensitivity in both muscle and liver in obese individuals. Design and Participants: Sixty-four nondiabetic obese adults (29 males) underwent hyperinsulinemic (15 and 80 mU/m2 · min)-euglycemic clamps with deuterated glucose. Top tertile subjects for glucose infusion rate during the high-dose insulin clamp were assigned Musclesen and those in the lower two tertiles were assigned Muscleres. Secondarily, top tertile subjects for endogenous glucose production suppression during the low-dose insulin clamp were deemed Liversen and the remainder Liverres. Main Outcomes Measures: Clinical and laboratory parameters and visceral, subcutaneous, liver, and pancreatic fat were compared. Results: Musclesen and Muscleres had similar body mass index and total fat (P > .16), but Musclesen had lower glycated hemoglobin (P < .001) and systolic (P = .01) and diastolic (P = .03) blood pressure (BP). Despite similar sc fat (P = 1), Musclesen had lower visceral (P < .001) and liver (P < .001) fat. Liversen had lower visceral (P < .01) and liver (P