Skip to main content

Table 1 Characteristics of 109,267 premenopausal Nurses' Health Study II participants in 1989 according to body fatness at age 10 years

From: Body fatness during childhood and adolescence and incidence of breast cancer in premenopausal women: a prospective cohort study

Characteristic

Figure at age 10 years

 

1

2

3

4

≥ 5

Number participants (%)

20,554 (18.8)

33,512 (30.7)

24,666 (22.6)

17,274 (15.8)

13,261 (12.1)

Mean

   Age (years)

34.6

34.0

34.1

34.3

34.7

   Total caloric intake in high school (kilocalories)a

2737

2746

2745

2746

2781

   Animal fat intake in high school (% energy)a

26.0

25.7

25.8

25.9

26.2

   Vegetable fat intake in high school (% energy)a

14.4

14.7

14.8

15.0

15.0

   Age at menarche (years)

12.8

12.6

12.3

12.1

12.0

   Height (inches)

64.9

64.9

64.8

64.8

65.0

   BMI at age 18 years (kg/m2)

19.3

20.2

21.5

22.9

24.3

   Current BMI (kg/m2)

22.0

22.7

24.4

26.1

27.1

   Age at first birth (years)b

25.4

25.5

25.6

25.6

25.4

   Parityb

2.1

2.1

2.1

2.1

2.0

Percentage

   Birthweight ≥ 8.5 lb

8.3

9.4

11.7

12.9

13.7

   ≥ 3 years from menarche until regular menstrual cycles

19.5

18.5

17.7

17.9

19.6

   Irregular menstrual cycles/no periods ages 18–22 years

9.7

9.0

8.8

10.2

11.2

   Menstrual cycle length ≥ 40 days ages 18–22 years

7.1

7.1

7.3

8.2

8.6

   Strenuous activity 10–12 months/year in high school

28.7

28.0

26.2

21.4

17.6

   BMI at age 18 years ≥ 25 kg/m2

1.8

3.1

8.9

19.5

32.2

   Current BMI ≥ 30 kg/m2

3.0

4.9

11.2

20.2

24.6

   Nulliparous

29.6

29.2

29.3

31.3

35.0

   Current oral contraceptive user

13.8

14.0

12.6

12.7

11.6

   Current smoker

13.1

11.5

12.3

14.2

18.6

   Alcohol consumption ≥ 10 g/day

9.7

9.0

9.1

9.1

9.9

   First-degree family history of breast cancer

5.9

6.0

5.7

5.9

6.3

   History of benign breast disease

30.3

28.1

27.6

27.5

28.0

  1. All means and percentages refer to the 1989 time period unless otherwise noted. Participants who had a diagnosis of cancer (other than nonmelanoma skin cancer) and those for whom body fatness data were missing at ages 5, 10, or 20 years were excluded. aAmong participants who completed the high school diet questionnaire in 1998. bAmong participants who reported that they were parous in 1989. BMI, body mass index.