Descriptive characteristics of HUNT4 participants according to history of GDM
| Characteristics | Overall (n=7551) | No history of GDM (n=7425) | History of GDM (n=126) | P value |
| Age, years | 39.9 (7.7) | 39.9 (7.8) | 37.4 (7.1) | <0.001 |
| Birth country | 0.07 | |||
| Norway | 7065 (93.6) | 6952 (93.6) | 113 (89.7) | |
| Other | 486 (6.4) | 473 (6.4) | 13 (10.3) | |
| Education | 0.02 | |||
| Lower/upper secondary education | 2797 (37.0) | 2738 (36.9) | 59 (46.8) | |
| Tertiary education | 4754 (63.0) | 4687 (63.1) | 67 (53.2) | |
| Living with partner | 6431 (85.2) | 6321 (85.1) | 110 (87.3) | 0.5 |
| Parity | 0.62 | |||
| 1 birth | 855 (11.3) | 839 (11.3) | 16 (12.7) | |
| ≥2 births | 6696 (88.7) | 6586 (88.7) | 110 (87.3) | |
| Time since last birth, years | <0.001 | |||
| <1 | 528 (7.0) | 505 (6.8) | 23 (18.3) | |
| 1 to <5 | 1985 (26.3) | 1925 (25.9) | 60 (47.6) | |
| 5 to <10 | 1878 (24.9) | 1852 (24.9) | 26 (20.6) | |
| ≥10 | 3160 (41.9) | 3143 (42.3) | 17 (13.5) | |
| CVD in first degree relatives | 1293 (17.1) | 1267 (17.1) | 26 (20.6) | 0.29 |
| Diabetes in first degree relatives | 1563 (20.7) | 1514 (20.4) | 49 (38.9) | <0.001 |
| BMI | <0.001 | |||
| Underweight (<18.5 kg/m2) | 98 (1.3) | 98 (1.3) | 0 (0) | |
| Normal weight (18.5 to <25 kg/m2) | 3386 (44.8) | 3353 (45.2) | 33 (26.8) | |
| Overweight (25 to <30 kg/m2) | 2486 (32.9) | 2440 (32.9) | 46 (37.4) | |
| Obese (≥30 kg/m2) | 1559 (20.7) | 1515 (20.4) | 44 (35.8) | |
| Missing | 22 (0.3) | 19 (0.3) | 3 (1) | |
| Living with children under age 18 | 6479 (85.8) | 6367 (85.8) | 112 (88.9) | 0.32 |
The data are presented as mean±SD or n (%).
BMI, body mass index; CVD, cardiovascular disease; GDM, gestational diabetes mellitus; HUNT4, Trøndelag Health Study, fourth survey.