Table 1.
Baseline characteristics of study participants by area
| Characteristics | Overall | Area |
|
|---|---|---|---|
| Rural | Urban | ||
| Number of women | 264 979 | 151 332 | 113 647 |
| Mean (SD) age, years | 50.3 (10.4) | 49.6 (10.2) | 51.3 (10.6) |
| Socio-economic and lifestyle factors, % or mean (SD) | |||
| High school or above | 17.7 | 6.3 | 33.7 |
| Household income >20 000 CNY/year | 40.5 | 30 | 55.1 |
| Total physical activity, MET-h/day | 20.9 (12.8) | 22.8 (13.2) | 18.4 (11.9) |
| Current regular smoker | 2.3 | 2.7 | 1.7 |
| Weekly regular drinker | 2.1 | 2.1 | 2.1 |
| Ever use of oral contraceptive pill | 9.7 | 8.6 | 10.9 |
| Anthropometric measurements, % or mean (SD) | |||
| BMI, kg/m2 | 23.7 (3.3) | 23.4 (3.3) | 24.1 (3.4) |
| Overweight (BMI 25–29.9 kg/m2) | 28.7 | 26.3 | 31.5 |
| Obesity (BMI ≥ 30 kg/m2) | 4.3 | 3.6 | 5.0 |
| Percentage body fat | 31.9 (6.9) | 31.5 (7.0) | 32.4 (6.7) |
| Standing height, cm | 154.2 (5.9) | 153.3 (5.8) | 155.5 (5.9) |
| Height adjusted weight, kg | 56.5 (4.5) | 55.8 (4.4) | 57.3 (4.5) |
| Waist circumference, cm | 78.7 (9.2) | 78.1 (9.2) | 79.4 (9.2) |
| Abdominal obesity (WC ≥ 80 cm) | 42.9 | 40.6 | 45.3 |
| Hip circumference, cm | 90.9 (6.6) | 89.4 (6.1) | 92.9 (6.7) |
| Waist–hip ratio | 0.86 (0.07) | 0.87 (0.07) | 0.85 (0.07) |
| Reproductive factors, % or mean (SD) | |||
| Age at menarche, years | 15.4 (1.9) | 15.5 (1.9) | 15.3 (2.0) |
| Early menarche (≤12 years) | 5.4 | 4.6 | 6.6 |
| Parous women | 98.8 | 99.2 | 98.1 |
| Numbers of live births | 2.2 (1.3) | 2.5 (1.3) | 1.8 (1.2) |
| Parity >2 children | 31.5 | 38.4 | 22.3 |
| Age at first birth, yearsa | 23.4 (3.1) | 22.3 (2.6) | 24.7 (3.2) |
| Never breastfeda | 2.7 | 1.4 | 4.5 |
| Months of breastfeeding per childa | 15.0 (7.2) | 16.7 (7.7) | 12.6 (5.8) |
| Post-menopause at baseline | 48.4 | 49.2 | 47.4 |
| Age at menopause, yearsb | 48.5 (4.1) | 48.2 (4.2) | 48.9 (3.9) |
| Reproductive yearsb | 32.6 (4.4) | 32.2 (4.5) | 33.1 (4.3) |
aAmong parous women only; bamong post-menopausal women only. BMI, body mass index; SD, standard deviation; WC, waist circumference.