Table 1.
Participant characteristics
| Characteristic | Insulin AUC quartile | IFG | IGT | |||
|---|---|---|---|---|---|---|
| Q1 | Q2 | Q3 | Q4 | |||
| n (F/M) | 55 (15/40) | 56 (38/18) | 55 (40/15) | 55 (37/18) | 14 (6/8) | 19 (15/4) |
| Age (years) | 24 (6) | 24 (5) | 22 (5) | 24 (6) | 22 (3) | 24 (7) |
| Height (cm) | 179 (11) | 169 (12)* | 168 (10)* | 167 (16)*¶ | 177 (10) | 166 (9)*¶ |
| Weight (kg) | 76.2 (15.8) | 68.2 (17.1)* | 62.1 (16.7)* | 64.9 (18.8)* | 74.5 (21.0) | 62.8 (18.6) |
| BMI (kg/m2) | 24.1 (3.5) | 23.4 (3.8) | 22.3 (3.8) | 23.8 (5.7) | 23.6 (3.4) | 24.9 (5.1) |
| BMI > 25 kg/m2 (%) | 31 | 30 | 24 | 34 | 21 | 47 |
| Body fat (%)a | 19.1 ± 1.1 | 25.9 ± 1.0* | 28.9 ± 1.1* | 32.1 ± 1.4*† | 25.4 ± 2.6 | 32.2 ± 1.5*† |
| Fat mass (kg) | 12.7 (7.0) | 16.8 (6.1) | 17.2 (7.0)* | 20.8 (9.0)* | 18.0 (5.8) | 23.2 (7.3)* |
| Visceral fat (g) | 221 (255) | 97 (157) | 81 (168) | 162 (168) | 174 (193) | 185 (355) |
| Fat-free mass (kg) | 59.4 (15.0) | 46.8 (13.7)* | 42.5 (9.5)* | 42.0 (12.7)* | 57.0 (21.2) | 39.9 (8.7)* |
| SBP | 120 (15) | 119 (17) | 121 (18) | 120 (18) | 125 (13) | 120 (12) |
| DBP | 73 (11) | 73 (11) | 77 (10) | 80 (13)† | 71 (13) | 80 (8)† |
| Fasting glucose (mmol/l) | 5.4 ± 0.1 | 5.4 ± 0.1 | 5.3 ± 0.1 | 5.3 ± 0.1 | 6.3 ± 0.1*†‡§ | 5.5 ± 0.1¶ |
| 2 h glucose (mmol/l) | 4.7 (1.5) | 5.0 (1.4) | 5.0 (1.1) | 5.8 (1.9)*† | 5.6 (1.0) | 8.8 (1.4)*†‡§¶ |
| Fasting insulin (pmol/l) | 10.6 (8.9) | 17.5 (11.6) | 20.0 (15.8)* | 31.5 (22.9)*†‡ | 22.1 (11.3)* | 30.3 (23.4)*† |
| 2 h insulin (pmol/l) | 51.5 (60.8) | 106.0 (67.8)* | 156.8 (73.5)*† | 261.5 (168.8)*†‡ | 114.9 (114.8)*§ | 355.0 (314.7)*†‡¶ |
| Fasting C-peptide (pmol/l) | 199.3 (101.3) | 267.4 (153.9)* | 289.9 (147.8)* | 322.1 (214.7)* | 339.1 (121.0)* | 351.0 (222.5)* |
| Fasting NEFA (mmol/l) | 0.20 (0.15) | 0.23 (0.15) | 0.26 (0.17) | 0.22 (0.21) | 0.17 (0.19) | 0.35 (0.15)* |
| Fasting triacylglycerol (mmol/l) | 0.63 (0.25) | 0.59 (0.25) | 0.73 (0.22) | 0.86 (0.29)*† | 0.81 (0.39) | 0.94 (0.40)*† |
| Total cholesterol (mmol/l) | 3.9 (0.8) | 3.9 (1.0) | 4.2 (1.0) | 4.5 (1.0)*† | 4.1 (0.9) | 4.3 (1.1) |
| HDL-cholesterol (mmol/l) | 1.4 (0.4) | 1.4 (0.4) | 1.5 (0.4) | 1.5 (0.5) | 1.4 (0.3) | 1.5 (0.6) |
| Non-HDL-cholesterol (mmol/l) | 2.4 (0.7) | 2.4 (0.8) | 2.7 (0.9) | 2.8(1.4)* | 2.7 (0.9) | 2.9 (0.8) |
| Family history of diabetes (%) | 16 | 20 | 35 | 31 | 36 | 5 |
| Smokers (%) | 5 | 4 | 2 | 4 | 0 | 5 |
| Energy intake (MJ)b | 10.9 (4.0) | 8.7 (2.5)* | 8.1 (2.4)* | 7.5 (2.8)* | 10.9 (3.0) | 7.2 (3.4)* |
| % carbohydrate | 38.3 (14.0) | 40.9 (11.1) | 38.8 (9.1) | 42.0 (8.8) | 35.9 (8.5) | 38.3 (8.7) |
| % protein | 20.7 (5.2) | 18.0 (5.7) | 19.5 (5.8) | 18.4 (4.0) | 23.0 (7.2) | 21.9 (8.1) |
| % fat | 34.1 (9.9) | 34.1 (10.1) | 36.7 (8.5) | 33.4 (9.1) | 37.7 (3.4) | 36.6 (5.3) |
| Contraceptive use (% women) | 7 | 11 | 23 | 30 | 33 | 33 |
| White (%) | 94 | 84 | 76 | 62 | 93 | 74 |
| Asian (%) | 4 | 16 | 24 | 34 | 7 | 26 |
| Other (%) | 2 | 0 | 0 | 4 | 0 | 0 |
Data are mean ± SEM, median (interquartile range) or proportion (%) as appropriate
aData on body composition (percentage fat, fat mass, visceral fat and lean mass) are from n = 45 for Q1, n = 40 for Q2, n = 43 for Q3, n = 30 for Q4, n = 9 for IFG and n = 17 for IGT
bData on energy and macronutrient intake are from n = 40 for Q1, n = 45 for Q2, n = 42 for Q3, n = 34 for Q4, n = 10 for IFG and n = 12 for IGT
*p < 0.05 vs Q1
†p < 0.05 vs Q2
‡p < 0.05 vs Q3
§p < 0.05 vs Q4
¶p < 0.05 vs IFG
F/M, female/male