Table 1.
Baseline characteristics according to weight change from age 25 to baseline among 411,812 participants
| Weight change from age 25 to baseline (kg) | Ptrend | |||||||
|---|---|---|---|---|---|---|---|---|
| ≤ − 5.0 | − 4.9–2.5 | − 2.4–2.4 | 2.5–4.9 | 5.0–9.9 | 10.0–14.9 | ≥ 15.0 | ||
| Participants (n (%)) | 53,658 (13.0) | 31,598 (7.7) | 85,757 (20.8) | 45,717 (11.1) | 84,370 (20.5) | 57,934 (14.1) | 52,778 (12.8) | |
| BMI and weight change (mean (SD)) | ||||||||
| BMI at age 25* (kg/m2) | 24.3 (2.6) | 22.9 (2.3) | 22.1 (2.3) | 21.7 (2.3) | 21.4 (2.2) | 21.1 (2.2) | 20.5 (2.3) | < 0.001 |
| BMI at baseline (kg/m2) | 20.6 (2.4) | 21.4 (2.3) | 22.1 (2.4) | 23.2 (2.3) | 24.3 (2.3) | 25.8 (2.3) | 28.3 (2.9) | < 0.001 |
| Weight change (kg) | − 9.0 (3.8) | − 3.6 (0.7) | 0.1 (1.4) | 3.7 (0.7) | 7.4 (1.4) | 12.2 (1.4) | 20.4 (5.1) | < 0.001 |
| Demographic and socioeconomic characteristics | ||||||||
| Age (year (SD)) | 55.6 (10.7) | 51.6 (10.6) | 49.6 (10.5) | 49.0 (10.2) | 49.5 (9.9) | 50.4 (9.8) | 51.4 (9.8) | < 0.001 |
| Women (%) | 49.5 | 54.6 | 58.8 | 63.1 | 61.8 | 57.7 | 52.9 | < 0.001 |
| Urban area (%) | 34.2 | 37.0 | 40.6 | 46.9 | 51.7 | 57.7 | 64.1 | < 0.001 |
| Middle school or above (%) | 50.0 | 50.9 | 53.0 | 55.1 | 55.7 | 56.1 | 55.6 | < 0.001 |
| Married (%) | 89.8 | 90.9 | 91.1 | 91.7 | 92.2 | 92.5 | 92.8 | < 0.001 |
| Agricultural and industrial worker (%) | 62.1 | 60.2 | 58.2 | 55.4 | 53.2 | 50.6 | 47.6 | < 0.001 |
| Household income ≥ 10,000 RMB/year (%) | 70.9 | 72.5 | 74.0 | 75.8 | 76.9 | 77.9 | 78.6 | < 0.001 |
| Lifestyle factors | ||||||||
| Male current smoker† (%) | 77.7 | 73.0 | 69.2 | 66.1 | 63.3 | 62.1 | 61.3 | < 0.001 |
| Female current smoker† (%) | 4.2 | 2.9 | 2.4 | 2.1 | 2.2 | 2.3 | 2.5 | <0.001 |
| Male daily alcohol drinker (%) | 22.5 | 23.0 | 22.6 | 22.4 | 20.9 | 20.2 | 19.1 | < 0.001 |
| Female daily alcohol drinker (%) | 1.1 | 1.0 | 1.0 | 0.9 | 0.9 | 1.0 | 0.9 | 0.023 |
| Physical activity, MET-hour/day | 22.3 | 22.5 | 22.0 | 21.5 | 21.1 | 20.5 | 19.6 | < 0.001 |
| Dairy product consumption more than once per week (%) | 21.4 | 21.6 | 22.2 | 23.1 | 23.1 | 22.6 | 21.6 | 0.145 |
| Calcium, iron, or zinc supplementation (%) | 6.4 | 6.6 | 6.7 | 7.1 | 7.3 | 7.8 | 8.1 | < 0.001 |
| Self-reported conditions (%) | ||||||||
| Diabetes | 5.9 | 4.8 | 4.5 | 4.7 | 5.3 | 6.4 | 8.1 | < 0.001 |
| COPD | 9.4 | 7.5 | 6.7 | 6.4 | 5.9 | 5.8 | 5.5 | < 0.001 |
| Self-rated poor health (%) | 14.1 | 10.5 | 8.7 | 8.0 | 8.0 | 8.7 | 9.8 | < 0.001 |
| Male height (m) | 1.6 | 1.6 | 1.6 | 1.7 | 1.7 | 1.7 | 1.7 | < 0.001 |
| Female height (m) | 1.5 | 1.5 | 1.5 | 1.5 | 1.5 | 1.6 | 1.6 | < 0.001 |
| Postmenopausal women (%) | 51.6 | 49.8 | 49.4 | 48.6 | 48.4 | 48.4 | 48.1 | < 0.001 |
BMI, body mass index; MET, metabolic equivalent of task; COPD, chronic obstructive pulmonary disease. All values are adjusted for age, sex, and survey site, as appropriate, except for BMI and weight change, age, sex, and region
*BMI at age 25 was calculated using self-reported weight at age 25 and measured height at baseline
†Participants who had stopped smoking because of illness were included in the current smokers in the present study