Table 1. Baseline Characteristics of the Study Participants*.
| IRS1 rs2943641 Genotype | ||||
|---|---|---|---|---|
| CC (n=331) | CT (n=312) | TT (n=95) | P | |
| Age, yr | 51 ± 9 | 51 ± 9 | 50 ± 9 | 0.55 |
| Sex, n (%) | 0.19 | |||
| Female | 213 (64.4) | 179 (57.4) | 59 (62.1) | |
| Male | 118 (35.6) | 133 (42.6) | 36 (37.9) | |
| Race or ethnic group, n (%) | 0.01 | |||
| White | 258 (43.7) | 259 (43.8) | 74 (12.5) | |
| Black | 61 (54.9) | 34 (30.6) | 16 (14.4) | |
| Hispanic | 5 (20.0) | 17 (68.0) | 3 (12.0) | |
| Asian or other | 7 (63.6) | 2 (18.2) | 2 (18.2) | |
| Diet groups (fat/protein/carbohydrate), n (%)† | 0.63 | |||
| Group 1 (20/15/65%) | 83 (44.4) | 82 (43.8) | 22 (11.8) | |
| Group 2 (20/25/55%) | 91 (50.0) | 69 (37.9) | 22 (12.1) | |
| Group 3 (40/15/45%) | 74 (39.8) | 86 (46.2) | 26 (14.0) | |
| Group 4 (40/25/35%) | 83 (45.4) | 75 (41.0) | 25 (13.7) | |
| Height, m | 1.68 ± 0.09 | 1.69 ± 0.09 | 1.69 ± 0.08 | 0.80 |
| Weight, kg | 94 ± 15 | 93 ± 16 | 94 ± 16 | 0.50 |
| BMI, kg/m2 | 33 ± 4 | 32 ± 4 | 33 ± 4 | 0.47 |
| Waist circumference, cm | 104 ± 12 | 103 ± 13 | 105 ± 14 | 0.91 |
| Blood pressure, mmHg | ||||
| Systolic | 121 ± 13 | 119 ± 13 | 119 ± 13 | 0.08 |
| Diastolic | 77 ± 9 | 75 ± 9 | 74 ± 10 | 0.005 |
| Glucose, mg/dl | 92 ± 13 | 92 ± 11 | 91 ± 12 | 0.30 |
| Insulin, μU/ml‡ | 10.8 (7.1-16.9) | 10.4 (6.9-14.9) | 9.3 (6.4-13.4) | 0.005 |
| HOMA-IR‡ | 2.4 (1.5-4.1) | 2.3 (1.5-3.5) | 2.0 (1.4-2.9) | 0.005 |
| Cholesterol, | ||||
| Total, mg/dl | 204 ± 36 | 200 ± 36 | 202 ± 41 | 0.39 |
| LDL, mg/dl | 127 ± 32 | 124 ± 31 | 127 ± 36 | 0.81 |
| HDL, mg/dl | 49 ± 14 | 49 ± 15 | 48 ± 13 | 0.64 |
| Triglycerides, mg/dl | 147 ± 81 | 142 ± 92 | 137 ± 82 | 0.12 |
| Dietary intake per day | ||||
| Energy, kcal | 1943 ± 546 | 1995 ± 593 | 1949 ± 531 | 0.91 |
| Carbohydrate, % | 44 ± 8 | 45 ± 8 | 46 ± 7 | 0.17 |
| Fat, % | 37 ± 6 | 37 ± 6 | 36 ± 6 | 0.18 |
| Protein, % | 18 ± 4 | 18 ± 3 | 18 ± 3 | 0.56 |
| Urinary nitrogen, g | 12.3 ± 4.6 | 12.1 ± 4.3 | 12.1 ± 4.4 | 0.26 |
| Respiratory quotient | 0.84 ± 0.04 | 0.84 ± 0.04 | 0.84 ± 0.04 | 0.66 |
*
Data are n (%), means ± SD or median (IQR). P-values were calculated by χ2 test for categorical variables, and F tests after adjusted for age, sex and ethnicity for continuous variables.
†
The targeted percentages of energy derived from fat, protein and carbohydrate from group 1 to group 4 were 20, 15 and 65%; 20, 25 and 55%; 40, 15, and 45%; 40, 25 and 35%.
‡
These variables were log-transformed before analysis.