Phenotypic Characterization of Insulin-Resistant and Insulin-Sensitive Obesity

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 systol...