In Gen3G, we measured glucose levels fasting and at 60 and 120 min after oral glucose administration using the hexokinase method (Roche Diagnostics, Indianapolis, IN). Insulin and C-peptide levels were measured at the same time points using multiplexed particle-based flow cytometric assays (Human Milliplex MAP kits; EMD Millipore).
In HAPO, glucose (fasting and at 60- and 120-min postglucose load) and C-peptide (fasting and at 60-min postglucose load) were measured in a central laboratory using a chemical analyzer (VITROS 750; Ortho Clinical Diagnostics) and immunoassay (AutoDELFIA; PerkinElmer), respectively (20 (link)).
In Gen3G, the Stumvoll first-phase estimate was used to estimate insulin secretion, and the Matsuda index was used to estimate insulin sensitivity (the opposite of insulin resistance) (21 (link),22 (link)). In both cohorts, insulin sensitivity was also assessed using a C-peptide–based measurement derived in the HAPO study (23 (link)).
In HAPO, glucose (fasting and at 60- and 120-min postglucose load) and C-peptide (fasting and at 60-min postglucose load) were measured in a central laboratory using a chemical analyzer (VITROS 750; Ortho Clinical Diagnostics) and immunoassay (AutoDELFIA; PerkinElmer), respectively (20 (link)).
In Gen3G, the Stumvoll first-phase estimate was used to estimate insulin secretion, and the Matsuda index was used to estimate insulin sensitivity (the opposite of insulin resistance) (21 (link),22 (link)). In both cohorts, insulin sensitivity was also assessed using a C-peptide–based measurement derived in the HAPO study (23 (link)).
