Table 1.
Selected baseline characteristics of women age ≥45 years in the California Teachers Study (CTS) cohort by body mass index (BMI)
| Characteristic | BMI (Body mass index)
|
||||||||
|---|---|---|---|---|---|---|---|---|---|
| <25
|
25–29
|
≥30
|
|||||||
| Median (IQR) | n | (%) | Median (IQR) | n | (%) | Median (IQR) | n | (%) | |
| BMI (kg/m2) | 32,941 | 58.7 | 14,980 | 26.7 | 8,170 | 14.6 | |||
| Age (years) | 54 (49–64) | 56 (50–66) | 55 (49–64) | ||||||
| Wine g/d | 3.3 (0–3.3) | 3.3 (0–3.3) | 3.3 (0–3.3) | ||||||
| Height (inches) | 65 (63–66) | 65 (63–66) | 64 (63–66) | ||||||
| Race | |||||||||
| White | 29,790 | 90.4 | 13,354 | 89.2 | 7,136 | 87.3 | |||
| Non-white | 3,151 | 9.6 | 1,626 | 10.9 | 1,034 | 12.7 | |||
| Strenuous and moderate physical activity (hours/week) in the 3 years before baseline | |||||||||
| Both < 0.5 h/week | 7,305 | 22.2 | 4,320 | 28.8 | 3,444 | 42.2 | |||
| Intermediate | 14,820 | 45.0 | 6,879 | 45.9 | 3,471 | 42.5 | |||
| Either ≥3.01 h/week | 10,816 | 32.8 | 3,781 | 25.2 | 1,255 | 15.4 | |||
| Total number of full-term pregnancies | |||||||||
| None | 7,140 | 21.7 | 2,945 | 19.7 | 1,917 | 23.5 | |||
| 1 | 4,945 | 15.0 | 2,015 | 13.5 | 1,146 | 14.0 | |||
| ≥2 | 20,856 | 63.3 | 10,020 | 66.9 | 5,107 | 62.5 | |||
| Oral contraceptive duration (years) | |||||||||
| Never used | 11,031 | 33.5 | 5,918 | 39.5 | 3,119 | 38.2 | |||
| <5 | 9,899 | 30.1 | 4,179 | 27.9 | 2,504 | 30.7 | |||
| ≥5 | 12,011 | 36.5 | 4,883 | 32.6 | 2,547 | 31.2 | |||
| Smoking history | |||||||||
| Never | 20,048 | 60.9 | 9,065 | 60.5 | 5,040 | 61.7 | |||
| Former | 10,911 | 33.1 | 5,036 | 33.6 | 2,752 | 33.7 | |||
| Current | 1,982 | 6.0 | 879 | 5.9 | 378 | 4.6 | |||
| History of tubal ligation | |||||||||
| No | 27,684 | 84.0 | 12,524 | 83.6 | 6,822 | 83.5 | |||
| Yes | 5,257 | 16.0 | 2,456 | 16.4 | 1,348 | 16.5 | |||
| Hormone therapy use (years) | |||||||||
| Never used | 15,651 | 47.5 | 6,937 | 46.3 | 4,366 | 53.4 | |||
| ≤5 | 9,164 | 27.8 | 4,235 | 28.3 | 2,256 | 27.6 | |||
| >5 | 8,126 | 24.7 | 3,808 | 25.4 | 1,548 | 19.0 | |||
| BMI at age 18 (kg/m2) | |||||||||
| <25 | 29,918 | 92.2 | 13,668 | 92.5 | 6,278 | 77.7 | |||
| ≥25 | 2,536 | 7.8 | 1,104 | 7.5 | 1,804 | 22.3 | |||
| Missing or unreliable | 487 | 208 | 88 | ||||||
| Weight change (pounds) since age 18 | |||||||||
| Loss, >10 lb | 4,823 | 14.8 | 355 | 2.4 | 55 | 0.7 | |||
| Stable, ±10 lb | 13,566 | 41.6 | 864 | 5.8 | 146 | 1.8 | |||
| Gain, 11–39 lb | 13,705 | 42.0 | 8,128 | 54.8 | 739 | 9.1 | |||
| ≥40 lb | 511 | 1.6 | 5,493 | 37.0 | 7,174 | 88.4 | |||
| Missing or unreliable | 336 | 140 | 56 | ||||||
| Waist (inches)a | |||||||||
| <35 | 21,087 | 88.7 | 4,509 | 46.1 | 409 | 8.9 | |||
| ≥35 | 2,687 | 11.3 | 5,272 | 53.9 | 4,195 | 91.1 | |||
| Waist-to-height ratioa | |||||||||
| <0.55 | 21,834 | 91.8 | 5,445 | 55.7 | 527 | 11.5 | |||
| ≥0.55 | 1,940 | 8.2 | 4,336 | 44.3 | 4,077 | 88.6 | |||
| Waist-to-hip ratioa | |||||||||
| <0.80 | 13,900 | 58.5 | 3,086 | 31.6 | 783 | 17.0 | |||
| ≥0.80 | 9,874 | 41.5 | 6,695 | 68.5 | 3,821 | 83.0 | |||
IQR interquartile range, BMI body mass index, E estrogen, P progestin
a
Available only among participants who completed the 1997 follow-up questionnaire