Table 1 Characteristics of study participants¹

Number

227

76

76

75

–

Follow-up time (years)

16.3 ± 1.02

16.9 ± 1.17

16.4 ± 0.84

15.6 ± 0.48

–

 Age (years)

37.2 ± 6.33

35.2 ± 6.58

38.3 ± 6.17

38.2 ± 5.82

0.003

 Housewife (n(%))

183 (80.6)

61 (80.3)

64 (84.2)

58 (77.3)

0.562

 Education > 12 years (n(%))³

132 (58.1)

44 (59.5)

49 (65.3)

39 (53.4)

0.337

 Never smokers (n(%))

219 (96.5)

75 (98.7)

72 (95.0)

72 (96.0)

0.546

 Baseline BMI (kg/m²)⁴

26.9 ± 4.3

26.3 ± 4.37

27.1 ± 3.99

27.3 ± 4.59

0.319

  < 25 (n(%))

74 (32.6)

29 (38.2)

18 (24)

27 (36.5)

0.226

 25–29.9 (n(%))

104 (45.8)

34 (44.7)

41 (54.7)

29 (39.2)

  ≥ 30 (n(%))

47 (20.7)

13 (17.1)

16 (21.3)

18 (24.3)

 BMI change during follow-up (kg/m²)⁵

2.77 ± 3.72

2.52 ± 3.10

2.59 ± 3.43

3.19 ± 4.49

0.511

 Age at menarche (years)⁶

13.5 ± 1.37

13.4 ± 1.51

13.4 ± 1.26

13.7 ± 1.34

0.447

 Baseline AMH (ng/ml)

0.55 (0.22, 1.54)

0.41 (0.12, 1.60)

0.50 (0.16, 0.91)

0.72 (0.35, 1.95)

0.004

 Annual decline in AMH⁷ (%)

5.68 (4.93, 6.04)

4.42 (3.33, 4.96)

5.68 (5.52, 5.84)

6.16 (6.04, 6.36)

< 0.001

 Energy (kcal/day)

2274 ± 688

2328 ± 676

2225 ± 654

2268 ± 737

0.653

 Carbohydrate (% of energy)

58.1 ± 5.94

57.6 ± 5.16

58.3 ± 6.77

58.3 ± 5.84

0.691

 Fat (% of energy)

30.9 ± 5.26

31.1 ± 4.78

31.1 ± 5.35

30.4 ± 5.66

0.676

 Protein (% of energy)

13.5 ± 2.16

13.6 ± 1.99

13.5 ± 2.21

13.5 ± 2.30

0.922