Table 1.
Baseline population characteristics according to number of optimal modifiable factors in women with a history of gestational diabetes mellitus, based on data from the Nurses’ Health Study II (n=4275)*
| Characteristic |
No of optimal modifiable factors† | |||||
|---|---|---|---|---|---|---|
| 0 (n=83) | 1 (n=810) | 2 (n=1470) | 3 (n=1284) | 4 (n=546) | 5 (n=82) | |
| Mean (SD) age (years) | 37.1 (4.6) | 37.4 (4.5) | 37.1 (4.4) | 36.8 (4.4) | 37.4 (4.4) | 37.6 (4.2) |
| Mean (SD) age (years) at first report of gestational diabetes mellitus | 30.1 (5.0) | 30.8 (5.3) | 30.5 (5.2) | 30.2 (5.3) | 31 (5.0) | 30.9 (4.3) |
| White participants | 78 (94.0) | 746 (92.1) | 1331 (90.5) | 1170 (91.1) | 512 (93.8) | 79 (96.3) |
| Family history of diabetes | 24 (28.9) | 273 (33.7) | 448 (30.5) | 352 (27.4) | 141 (25.8) | 17 (20.7) |
| Mean (SD) age at first birth (years) | 26.3 (4.7) | 27.5 (4.9) | 27.5 (4.7) | 27.5 (4.8) | 28.4 (4.8) | 29.5 (4.1) |
| Median (IQR) parity | 2 (2-3) | 2 (2-3) | 2 (2-3) | 2 (2-3) | 2 (2-3) | 2 (2-2) |
| Total duration of breastfeeding | ||||||
| ˂1 month | 34 (41.0) | 245 (30.2) | 373 (25.4) | 273 (21.3) | 100 (18.3) | 7 (8.5) |
| 1-6 months | 15 (18.1) | 130 (16.0) | 227 (15.4) | 182 (14.2) | 76 (13.9) | 17 (20.7) |
| 6-12 months | 14 (16.9) | 139 (17.2) | 284 (19.3) | 226 (17.6) | 106 (19.4) | 19 (23.2) |
| ≥12 months | 20 (24.1) | 296 (36.5) | 586 (39.9) | 603 (47.0) | 264 (48.4) | 39 (47.6) |
| Oral contraceptive use | ||||||
| Never | 6 (7.2) | 99 (12.2) | 230 (15.6) | 201 (15.7) | 72 (13.2) | 9 (11.0) |
| Past | 73 (88.0) | 655 (80.9) | 1129 (76.8) | 976 (76.0) | 441 (80.8) | 70 (85.4) |
| Current | 4 (4.8) | 56 (6.9) | 111 (7.6) | 107 (8.3) | 33 (6.0) | 3 (3.7) |
| Menopausal status | ||||||
| Pre-menopausal | 79 (95.2) | 786 (97.0) | 1428 (97.1) | 1255 (97.7) | 536 (98.2) | 81 (98.8) |
| Post-menopausal | 4 (4.8) | 24 (3.0) | 42 (2.9) | 29 (2.3) | 10 (1.8) | 1 (1.2) |
| Mean (SD) body mass index | 31.9 (5.0) | 31.6 (6.9) | 27.5 (6.0) | 24.8 (4.9) | 22.2 (2.5) | 21.7 (1.8) |
| Modified AHEI score, mean (SD)‡ | 36 (6.3) | 36.8 (7.1) | 39.6 (8.2) | 44.5 (9.6) | 51.5 (8.3) | 54.6 (7.0) |
| Total energy intake, mean (SD), kcal/day | 1771 (460) | 1899 (544) | 1920 (554) | 1872 (543) | 1856 (529) | 1905 (562) |
| Smoking status, No. (%) | ||||||
| Never | 0 | 500 (61.7) | 1028 (69.9) | 916 (71.3) | 382 (70.0) | 46 (56.1) |
| Past | 0 | 152 (18.8) | 294 (20.0) | 318 (24.8) | 159 (29.1) | 36 (43.9) |
| Current | 83 (100.0) | 158 (19.5) | 148 (10.1) | 50 (3.9) | 5 (0.9) | 0 (0.0) |
| Mean (SD) duration of leisure time physical activity (MET-h/week)§ | 3.1 (2.1) | 5 (8.5) | 14.2 (19.4) | 23.7 (24.4) | 30.3 (31.8) | 33.7 (27.1) |
| Median (IQR) alcohol intake (g/day) | 0.6 (0-1.9) | 0 (0-1.1) | 0 (0-1.8) | 0.9 (0-2.7) | 1.8 (0-6.2) | 8.7 (6.6-11.4) |
Data are number (%) of participants unless stated otherwise. AHEI=Alternate Healthy Eating Index; MET=metabolic equivalent; IQR=interquartile range; SD=standard deviation.
Baseline was defined as the first pregnancy questionnaire cycle after incident gestational diabetes mellitus during follow-up, and the questionnaire cycle in 1991 for prevalent gestational diabetes mellitus at the start of follow-up (in 1991).
The optimal level of each factor was defined as follows: currently non-smoker (including never or past smoker); body mass index <25.0; top two groups of the modified AHEI score (divided by quintiles); ≥150 min/week of moderate intensity physical activity or ≥75 min/week of vigorous intensity physical activity; alcohol intake 5.0-14.9 g/day.
AHEI score excluding the component of alcohol was used in the current analysis (possible score range 0-100).
MET values from moderate or vigorous intensity of leisure time activities were summed up to derive total physical activities; 7.5 MET-h/week is equivalent to 150 min/week of moderate intensity physical activity or 75 min/week of vigorous intensity physical activity.