Table 3: Ethnic comparison of insulin secretory function as determined by C-peptide levels.

Insulin response by ethnicity
BA > WENo significant ethnic differenceBA < WE

NGT[48] (OGTT)
[52] (IVGTT)
[56] (IVGTT)
[28] (OGTT, obese only)
[34] (OGTT)
[63] (IVGTT)
[28] (OGTT, lean only)
[29] (MMTT)
[50] (GCT)
[25] (oral glucose, IV tolbutamide and glucagon)

“Prediabetic”[36] (OGTT)
[37] (OGTT)

T2D[30] (MMTT, HC)

Mixed[31] (OGTT)
[42] (OGTT)

Cumulative 2621005753

Cumulative refers to the total number of participants (BA and WE) in the studies. BA: black African; WE: white European; NGT: normal glucose tolerance; T2D: type 2 diabetes; IVGTT: intravenous glucose tolerance test; OGTT: oral glucose tolerance test; GCT: glucose challenge test; MMTT: mixed meal tolerance test; HC: hyperglycaemic clamp.