OBJECTIVE To compare insulin sensitivity (M/I) and β-cell responses in youth versus adults
with impaired glucose tolerance (IGT) or drug-naïve, recently diagnosed type 2 diabetes.
RESEARCH DESIGN AND METHODS In 66 youth (80.3% with IGT) and 355 adults (70.7%
IGT), hyperglycemic clamps were used to measure 1) M/I, 2) acute (0–10 min [first phase]) C-
peptide (ACPRg) and insulin (AIRg) responses to glucose, 3) steady-state C-peptide and
insulin concentrations at plasma glucose of 11.1 mmol/L, and 4) arginine-stimulated …

OBJECTIVE To compare oral glucose tolerance test (OGTT) glucose, C-peptide, and insulin
responses and insulin sensitivity in youth and adults with impaired glucose tolerance (IGT)
or recently diagnosed type 2 diabetes. RESEARCH DESIGN AND METHODS A total of 66
youth (80.3% with IGT) and 355 adults (70.7% with IGT) underwent a 3-h OGTT to assess 1)
insulin sensitivity (1/fasting insulin), 2) C-peptide index (CPI) and insulinogenic index (IGI)
over the first 30 min, and 3) glucose, C-peptide, and insulin incremental areas above fasting …