Table 2.
Characteristics of Sample at Age 18 y
| Characteristic | All Sample | IR Absenta | IR Presenta | Test StatisticbP-value |
|---|---|---|---|---|
| Participants, n (%) | 2627 (100) | 2417 (92) | 210 (8) | — |
| Male sex, n (%) | 1522 (49) | 1403 (48.6) | 119 (47.6) | 0.10; P = .765 |
| Father’s social class, n (%) | ||||
| I | 143 (6) | 136 (5.7) | 7 (3.6) | 9.27; P = .089 |
| II | 929 (36) | 861 (36.3) | 68 (35.1) | |
| III | 1098 (43) | 1018 (42.9) | 80 (41.2) | |
| IV | 335 (13) | 305 (12.8) | 30 (15.5) | |
| V | 63 (2) | 68 (2.3) | 134 (4.6) | |
| White British ethnicity, n (%) | 2574 (97) | 2422 (97.9) | 212 (97.7) | 7.86; P = .453 |
| BMI at 18 y, mean (SD), kg/m2 | 22.71 | 22.39 (3.42) | 25.71 (5.56) | 3.48 P < .001* |
| FPG at 18 y, mean (SD), mmol/l | 5.03 (0.59) | 5.00 (0.43) | 5.34 (0.67) | 3.49; P < .001* |
| HOMA2 at 18 y, mean (SD) | 0.92 (0.73) | 0.77 (0.32) | 2.64 (1.52) | 1.86; P < .001* |
| CRP at 18 y, mean (SD), mg/l | 1.08 (1.41) | 1.07 (1.40) | 1.41 (1.62) | 0.35; P < .001* |
| IL-6 at age 9 y, mean (SD), pg/ml | 1.27 (1.59) | 1.28 (1.62) | 1.35 (1.41) | 0.08; P = .531 |
| CRP at age 9 y | 0.68 (2.52) | 0.69 (2.61) | 0.68 (1.31) | 0.01; P = .974 |
| Birthweight, mean (SD), gram | 3426.01 (549.86) | 3431.02 (550.45) | 3387.50 (525.38) | 43.52; P = .249 |
| Gestational age, mean (SD), wk | 39.41 (1.84) | 39.42 (1.83) | 39.40 (1.70) | 0.25; P = .841 |
| Smoking at age 18 y, n (%) (current) | 217 (6.86) | 192 (6.6) | 25 (10) | 3.94; P = .043* |
Note: BMI, body mass index; HOMA2, Homeostasis Model Assessment for Insulin Resistance; IL-6, interleukin-6; CRP, C-reactive protein.
*Denotes P < .05.
aHOMA2 score > 1.79.
bCategorical variables (sex, social class, ethnicity, smoking) were compared using a Chi-squared test, continuous variables (BMI, FPG, HOMA2, CRP, IL-6, Birthweight, Gestational Age) were compared using 2-tailed t test.