Table 2. Baseline insulin sensitivity, secretion, and clearance under basal and dynamic conditions by race/ethnicity.
| All participants (n=268) | African American (n=145) | European American (n=123) |
Unadjusted P value |
Adjusted P value* |
|
|---|---|---|---|---|---|
| Basal state | |||||
| Fasting insulin (µU/mL) | 8.19±7.31 | 7.79±5.72 | 8.69±8.87 | 0.35 | 0.16 |
| HOMA-B (%) | 91.8±66.9 | 92.5±57.4 | 91.0±71.8 | 0.85 | 0.27 |
| Basal insulin clearance | 19.2±10.6 | 17.3±9.36 | 21.1±11.6 | 0.008 | 0.026 |
| Dynamic state | |||||
| Si-clamp (mmol/kg fat-free mass.min/pM.) | 0.134±0.067 | 0.125±0.069 | 0.143±0.063 | 0.049 | 0.02 |
| M (μmol/kg fat-free mass) | 86.3±30.1 | 85.1±32.4 | 87.6±27.6 | 0.541 | 0.11 |
| Matsuda index | 6.07±3.86 | 6.20±4.16 | 5.91±3.47 | 0.59 | 0.44 |
| Insulinogenic index | 1.28±1.11 | 1.56±1.31 | 0.920±0.633 | <0.0001 | 0.005 |
| AUC-IVGT glucose (mg/dL/min) |
5306±444 | 5234±477 | 5392±386 | 0.0017 | 0.24 |
| AUC-IVGT insulin (µU/mL/min) |
1062±1004 | 1195±980 | 900±1013 | 0.013 | 0.002 |
| AIR (% increase) | 1798±1423 | 1805±1553 | 1269±1252 | 0.0024 | 0.0013 |
| Disposition index | 9.76±7.55 | 11.0±9.09 | 8.50±5.37 | 0.027 | 0.20 |
| Dynamic insulin clearance | 6.81±3.52 | 5.84±3.28 | 7.82±3.48 | <0.0001 | 0.0005 |
| MCR insulin (mL/m2 BSA/min) | 4.89±2.15 | 4.50±2.17 | 5.29±2.07 | 0.02 | 0.13 |
*
Adjusted for sex, age, maternal/paternal diabetes history, body mass index (BMI), waist circumference, fasting plasma glucose (FPG), and HbA1c at baseline.
AIR, acute insulin response to intravenous glucose; AUC-IVGT, area under the curve during intravenous glucose tolerance test; BSA, body surface area; HOMA-B, homeostasis model assessment of beta-cell function; M, glucose metabolized during euglycemic clamp; MCR, metabolic clearance rate of insulin during euglycemic clamp; Si-clamp, insulin sensitivity measured with hyperinsulinemic euglycemic clamp.