Table 1 Descriptive characteristics of post-menopausal women

Age (matching factor, years)

2,818/3,111

63.4 ± 6.7

64.3 ± 6.5

-

2,651/5,395

63.2 ± 5.6

63.2 ± 5.5

-

Age at menarche (years)

2,558/2,832

13.5 ± 1.4

13.6 ± 1.4

0.0565

2,369/4,580

13.6 ± 1.6

13.7 ± 1.7

0.0026

Age at menopause (years)

2,803/3,093

50.4 ± 3.5

50 ± 3.9

< 0.0001

1,614/3,417

49.5 ± 4.7

49.0 ± 5.0

0.0014

Parity (No. of live births)

2,818/3,110

1.8 ± 1.2

2.1 ± 1.4

< 0.0001

2,651/5,395

1.6 ± 1.1

1.7 ± 1.2

< 0.0001

Age at first birth (years)

2,373/2,753

25.3 ± 4.9

24.6 ± 4.6

< 0.0001

2,185/4,537

24.7 ± 4.6

24.5 ± 4.4

0.1879

Body mass index (kg/m2)

2,803/3,065

25.8 ± 4.2

25.5 ± 4.2

0.0009

2,651/5,390

23.2 ± 3.2

23.3 ± 3.3

0.7134

Alcohol consumption (g/day)

2,537/2,400

2.5 ± 4.5

2.1 ± 3.9

0.0032

2,649/5,389

8.9 ± 18.2

8.4 ± 13.8

0.1731

History of breast cancer in first degree relative (Yes, %)

2,745/2,607

15.6

7.7

< 0.0001

2,512/5,096

18.6

12.6

< 0.0001

History of benign breast disease (Yes, %)

2,818/3,111

13.9

8.1

< 0.0001

2,647/5,379

41.2

34.9

< 0.0001

Use of hormone replacement therapy (Ever, %)

2,811/3,087

48.4

40.3

< 0.0001

2,645/5,375

68.5

60.7

< 0.0001

Smoked > 1 year or > 100 cigarettes (Yes, %)

2,817/3,109

42.5

44.3

0.6490

2,651/5,393

46.2

46.4

0.8602

Education, categorical*

2,800/2,646

0.0797

2,649/5,395

0.4634

- elementary school

45.4

46.7

- junior secondary school

24.8

21.5

low

56.5

57.2

- high school

15.2

13.8

medium

28.4

28.7

- university

13.9

12.0

high

15.1

14.1

Physical activity one year before recruitment, categorical

2,794/2,936

0.0055

2,625/5,350

0.0031

- none

17.8

15.8

37.3

33.5

- < 1 h per week

15.8

14.9

23.9

23.9

- 1 to 2 h per week

33.6

28.1

17.1

18.2

- > 2 h per week

32.0

35.6

21.7

24.4