Table 1. Baseline characteristics of participants by BMI.
| Characteristic* | Men |
Women |
||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| BMI (kg/m2) | Total | BMI (kg/m2) | Total | |||||||
| <18.5 | 18.5-24.9 | 25.0-29.9 | ≥30 | <18.5 | 18.5-24.9 | 25.0-29.9 | ≥30 | |||
| No. of participants | 9108 | 129855 | 54161 | 5450 | 198574 | 12528 | 177202 | 81426 | 12859 | 284015 |
| Age and socioeconomic factors | ||||||||||
| Mean age (SD), y | 56.4 (14.4) | 52.2 (11.0) | 50.9 (11.0) | 49.7 (13.1) | 52.1 (10.9) | 53.1 (14.7) | 49.7 (10.4) | 51.2 (9.7) | 52.1 (10.9) | 50.5 (10.4) |
| ≥6 y education, % | 56.9 | 58.5 | 62.5 | 62.9 | 57.5 | 42.1 | 43.5 | 41.0 | 38.3 | 43.7 |
| Living in urban area, % | 29.0 | 36.2 | 56.4 | 66.0 | 42.2 | 33.6 | 41.8 | 48.5 | 51.5 | 43.7 |
| Occupation, % | ||||||||||
| Agriculture and related | 47.4 | 45.8 | 38.0 | 34.5 | 44.7 | 44.2 | 41.9 | 39.3 | 37.1 | 41.6 |
| Other | 32.0 | 36.5 | 41.8 | 42.7 | 36.4 | 21.7 | 24.1 | 23.1 | 20.8 | 24.1 |
| Retired/Housewife/Unemployed | 20.6 | 17.6 | 20.2 | 22.8 | 18.9 | 34.0 | 34.0 | 37.6 | 42.1 | 34.3 |
| Annual household income, % | ||||||||||
| <10,000 yuan | 33.5 | 27.4 | 22.3 | 19.8 | 26.4 | 34.5 | 30.0 | 29.4 | 30.2 | 29.9 |
| 10,000-19,999 yuan | 29.3 | 28.9 | 27.7 | 28.6 | 28.3 | 29.6 | 29.0 | 29.8 | 30.1 | 29.4 |
| >19,999 yuan | 37.2 | 43.6 | 50.1 | 51.6 | 45.3 | 35.9 | 41.0 | 40.8 | 39.7 | 40.6 |
| Lifestyle factors | ||||||||||
| Ever-regular smoker, % | 79.9 | 75.4 | 70.7 | 70.4 | 74.5 | 5.1 | 3.3 | 2.8 | 3.3 | 3.1 |
| Ever-regular alcohol drinker, % | 36.6 | 41.3 | 43.0 | 44.1 | 41.8 | 2.7 | 3.0 | 3.2 | 2.8 | 3.0 |
| Mean physical activity (SD), MET-h/d | 22.1 (18.7) | 23.4 (13.6) | 21.5 (14.0) | 19.6 (16.1) | 22.4 (15.3) | 20.4 (13.7) | 20.7 (10.5) | 20.1 (11.0) | 19.1 (12.7) | 20.8 (12.8) |
| Anthropometry, blood pressure and plasma glucose, mean (SD) | ||||||||||
| BMI, kg/m2 | 17.7 (0.9) | 22.0 (1.7) | 26.7 (1.4) | 31.5 (1.9) | 23.3 (3.2) | 17.5 (1.0) | 22.2 (1.7) | 26.8 (1.4) | 31.9 (2.3) | 23.7 (3.4) |
| Waist circumference, cm | 67.6 (6.0) | 78.3 (6.5) | 90.7 (6.3) | 102.1 (8.8) | 81.7 (9.7) | 64.3 (6.4) | 75.3 (6.3) | 86.0 (6.2) | 96.5 (8.4) | 78.7 (9.4) |
| Hip circumference, cm | 81.9 (5.7) | 88.5 (4.4) | 95.7 (4.5) | 102.9 (6.7) | 90.5 (6.8) | 81.6 (4.7) | 88.7 (4.4) | 95.6 (4.6) | 103.5 (6.5) | 91.0 (6.8) |
| Waist-to-hip ratio | 0.83 (0.08) | 0.88 (0.06) | 0.95 (0.05) | 0.99 (0.07) | 0.90 (0.06) | 0.79 (0.08) | 0.85 (0.06) | 0.90 (0.06) | 0.93 (0.07) | 0.86 (0.07) |
| Waist-to-height ratio | 0.41 (0.04) | 0.47 (0.04) | 0.55 (0.04) | 0.62(0.05) | 0.49 (0.06) | 0.42 (0.04) | 0.49 (0.04) | 0.56 (0.04) | 0.63 (0.05) | 0.51 (0.06) |
| Body fat percentage† | 12.8 (4.1) | 20.0 (4.4) | 27.3 (4.7) | 32.5 (7.0) | 21.9 (6.2) | 19.2 (3.3) | 29.2 (4.5) | 37.8 (4.5) | 45.3 (6.4) | 31.9 (7.1) |
| BMI at 25 y‡, kg/m2 | 20.0 (2.5) | 21.6 (2.1) | 22.5 (2.5) | 23.8 (3.5) | 21.9 (2.3) | 20.0 (2.8) | 21.5 (2.6) | 22.7 (2.9) | 23.9 (3.8) | 21.8 (2.7) |
| BMI change‡, kg/m2 | -2.3 (2.5) | 0.6 (2.5) | 4.3 (2.7) | 7.7 (3.7) | 1.6 (3.4) | -2.4 (2.8) | 0.7 (2.8) | 4.1 (3.0) | 8.0 (4.2) | 2.0 (3.6) |
| Proportional change in BMI (%) | -10.7 (11.4) | 3.5 (12.2) | 20.2 (13.8) | 34.1 (20.2) | 8.0 (16.3) | -11.1 (12.6) | 4.6 (13.6) | 19.7 (15.8) | 35.7 (23.4) | 10.1 (17.0) |
| SBP, mmHg | 121.7 (23.0) | 129.5 (18.1) | 137.5 (19.8) | 144.8 (27.7) | 132.4 (19.9) | 120.5 (25.3) | 127.3 (19.8) | 134.6 (20.8) | 141.3 (24.7) | 129.0 (21.6) |
| RPG§, mg/dL | 99.0 (27.0) | 99.0 (19.8) | 102.6 (23.4) | 106.2 (32.4) | 100.8 (21.6) | 100.8 (27.0) | 102.6 (19.8) | 106.2 (21.6) | 108.0 (27.0) | 102.6 (19.8) |
| Family history of diabetes, % | 4.6 | 5.5 | 7.4 | 8.2 | 6.0 | 4.2 | 6.2 | 7.4 | 8.0 | 6.7 |
*
Standardised to age and study area structure of the study population
†
Data missing for 226 participants
‡
Data missing for 77 745 participants
§
Data missing for 7975 participants. BMI, body mass index; MET-h/d, metabolic equivalent of task hours per day; RPG, random plasma glucose; SBP, systolic blood pressure. SI conversion factor: to convert glucose to mmol/L, multiply by 18.