Table 1.
Baseline characteristics of participants from the NHS II by history of GDM
| No history of GDM (n = 51,174; 94.7%) | History of GDM† (n = 2,888; 5.3%) | |
|---|---|---|
| Mean (SD) age, years | 43.4 (3.9) | 43.2 (3.8) |
| Mean (SD) weight, kg | 69.6 (15.9) | 75.1 (19.3) |
| Mean (SD) BMI, kg/m2 | 25.6 (5.6) | 27.9 (6.8) |
| White | 50,272 (98.2) | 2,824 (97.8) |
| Married | 49,682 (97.1) | 2,752 (95.3) |
| Family history of diabetes | 18,107 (35.4) | 1,482 (51.3) |
| Parity | ||
| 0 | 243 (0.5) | 17 (0.6) |
| 1 | 8,771 (17.1) | 393 (13.6) |
| 2 | 24,924 (48.7) | 1,308 (45.3) |
| 3 | 12,796 (25.0) | 810 (28.0) |
| 4+ | 4,440 (8.7) | 360 (12.5) |
| Oral contraceptive use | ||
| Current user | 3,113 (6.1) | 151 (5.2) |
| Past user | 41,632 (81.4) | 2,338 (81.0) |
| Never user | 6,429 (12.6) | 399 (13.8) |
| Combined menopausal and HRT use status | ||
| Premenopausal never HRT user | 44,556 (87.1) | 2,538 (87.9) |
| Postmenopausal never HRT user | 829 (1.6) | 41 (1.4) |
| Postmenopausal current HRT user | 1,347 (2.6) | 90 (3.1) |
| Postmenopausal past HRT user | 2,898 (5.7) | 128 (4.4) |
| Missing | 1,544 (3.0) | 91 (3.2) |
| Total daily sleep, h‡ | ||
| ≤6 | 13,699 (28.5) | 819 (29.9) |
| 7–8 | 31,979 (66.5) | 1,770 (64.7) |
| >8 | 2,408 (5.0) | 149 (5.4) |
| Mean (SD) total energy intake, kcal | 1,809 (549) | 1876 (573) |
| Mean (SD) AHEI score | 51.2 (11.9) | 51.2 (11.8) |
| Median physical activity (IQR), MET-h/week§ | 13.1 (5.7, 25.9) | 11.3 (4.9, 22.2) |
| Mean (SD) alcohol use, servings/day | 0.3 (0.6) | 0.2 (0.5) |
| Smoking status | ||
| Never | 33,875 (66.2) | 1,951 (67.6) |
| Past | 12,693 (24.8) | 700 (24.2) |
| Current | 4,606 (9.0) | 237 (8.2) |
Data are n (%) unless stated otherwise. Baseline was defined as first follow-up cycle when a woman reached age 40 years.
HRT, hormone replacement therapy; IQR, interquartile range.
†
History of ever reporting a pregnancy complicated by GDM.
‡
Duration of sleep was assessed in 2001 and 2009 questionnaires only. Numbers are presented based on sleep data collected in the 2001 questionnaires.
§
Metabolic equivalents from leisure-time physical activities of moderate or vigorous intensity were summed.