Table 1.
Age and Age-Standardized Characteristics of 103,577 Women by Body Mass Index and Physical Activity in the Nurses’ Health Study.*
| BMI (kg/m2) | Total physical activity, MET-hours/week | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| < 23 | 23–<25 | 25–27.5 | 27.5–<30 | ≥ 30 | < 3 | 3–<9 | 9–18 | 18–27 | ≥ 27 | |
| Age, y† | 62.2(8.2) | 62.4(7.7) | 62.8(7.6) | 63.0(7.4) | 62.8(7.2) | 61.2(9.4) | 60.7(8.9) | 61.0(8.8) | 61.1(8.6) | 61.4(8.4) |
| Age at menarche, y | 12.8(1.4) | 12.7(1.4) | 12.6(1.4) | 12.5(1.4) | 12.3(1.4) | 12.5(1.4) | 12.6(1.4) | 12.6(1.4) | 12.6(1.4) | 12.6(1.5) |
| Body mass index at age 18y, kg/m2‡ | 20.2(2.2) | 20.8(2.4) | 21.3(2.6) | 21.9(2.8) | 23.1(3.5) | 21.5(3.1) | 21.3(2.9) | 21.3(2.8) | 21.2(2.7) | 21.2(2.7) |
| Nulliparous, % | 7 | 6 | 6 | 5 | 5 | 5 | 5 | 5 | 5 | 6 |
| Parity, number of children§ | 3.2(1.5) | 3.3(1.6) | 3.3(1.6) | 3.3(1.6) | 3.3(1.6) | 3.2(1.6) | 3.2(1.5) | 3.2(1.5) | 3.1(1.5) | 3.1(1.5) |
| Age at first birth,y | 25.5(3.5) | 25.4(3.4) | 25.3(3.4) | 25.2(3.4) | 25.1(3.4) | 25.2(3.4) | 25.1(3.3) | 25.1(3.3) | 25.0(3.2) | 25.0(3.2) |
| Age at menopause,y‖ | 48.5(5.6) | 48.7(5.5) | 48.5(5.8) | 48.5(5.9) | 48.5(6.2) | 48.4(5.7) | 48.7(5.6) | 48.8(5.6) | 48.9(5.6) | 48.8(5.7) |
| Current PMH use, % | 37 | 36 | 34 | 32 | 28 | 30 | 33 | 35 | 36 | 36 |
| Mammography within past 2 y, % | 67 | 69 | 68 | 67 | 65 | 72 | 77 | 80 | 81 | 81 |
| Family history of breast cancer, % | 12 | 12 | 13 | 12 | 12 | 12 | 13 | 13 | 13 | 13 |
| History of benign breast disease, % | 43 | 43 | 41 | 40 | 39 | 43 | 44 | 46 | 47 | 47 |
| Weight gain since age 18 y, kg | 2.4(6.8) | 8.5(6.6) | 13.2(7.4) | 18.1(8.0) | 27.9(11.4) | 15.4(13.4) | 13.8(12.0) | 12.3(11.4) | 11.4(11.0) | 10.0(10.8) |
| Height, m | 1.6(0.1) | 1.6(0.1) | 1.6(0.1) | 1.6(0.1) | 1.6(0.1) | 1.6(0.1) | 1.6(0.1) | 1.6(0.1) | 1.6(0.01) | 1.6(0.1) |
| Alcohol, g/day | 7.1(11.3) | 6.4(10.5) | 5.6(10.1) | 4.7(9.3) | 3.4(8.0) | 5.0(10.4) | 5.1(9.5) | 5.4(9.5) | 5.8(9.6) | 6.3(10.0) |
| Total physical activity, MET-h/week | 19.3(20.6) | 17.5 (19.2) | 16.4(18.2) | 14.6(16.9) | 11.9(15.3) | 1.3(0.9) | 5.7(1.8) | 13.0(2.7) | 22.1(2.5) | 47.2(19.3) |
| Brisk walking, MET-h/wk | 5.0(10.0) | 4.3(9.1) | 3.5(8.2) | 2.6(7.1) | 1.4(5.4) | 0.1(0.9) | 2.5(4.3) | 2.5(4.3) | 5.9(8.2) | 10.4(14.2) |
The analysis of body mass index was restricted to postmenopausal women and characteristics of the aforementioned factors used data from the 1980 questionnaire except for the physical activity data from 1986. The analysis for physical activity included a total of 97,803 premenopausal and postmenopausal women and characteristics of the aforementioned factors used data from the 1986 questionnaire.
Values are means (SD) or percentages and were standardized to the age distribution of the study population.
Value is not age adjusted
Body mass index was calculated as weight in kilograms divided by the square of height in meters.
Among parous women only.
Among women with natural menopause or bilateral oophorectomy.