Table 1 The characteristics of the study participants
From: The joint effects of physical activity and air pollution on type 2 diabetes in older adults
| Â | Total | Individuals without type 2 diabetes | Individuals with type 2 diabetes | p |
|---|---|---|---|---|
Number of people | 36,562 | 32,584 | 3978 | Â |
Age, mean (SD) | 60.54 (7.50) | 60.38 (7.48) | 61.86 (7.55) |  < 0.001 |
Gender, n (%) |  |  |  |  < 0.001 |
 male | 15,041 (41.1) | 13,149 (40.4) | 1892 (47.6) |  |
 female | 21,521 (58.9) | 19,435 (59.6) | 2086 (52.4) |  |
Marital status, n (%) |  |  |  |  < 0.05 |
 Married or cohabiting | 31,446 (86.0) | 28,064 (86.1) | 3382 (85.0) |  |
 Widowed | 1095 (3.0) | 992 (3.0) | 103 (2.6) |  |
 Separated or divorced | 3908 (10.7) | 3427 (10.5) | 481 (12.1) |  |
 Never married | 113 (0.3) | 101 (0.3) | 12 (0.3) |  |
Income, n (%) | Â | Â | Â | 0.255 |
  < 12,000 ¥ | 8648 (23.7) | 7713 (23.7) | 935 (23.5) |  |
 12,000–19,999 ¥ | 7027 (19.2) | 6280 (19.3) | 747 (18.8) |  |
 20,000–59,999 ¥ | 12,630 (34.5) | 11,285 (34.6) | 1345 (33.8) |  |
 60,000–99,999 ¥ | 4815 (13.2) | 4272 (13.1) | 543 (13.7) |  |
  >  = 100 K ¥ | 3442 (9.4) | 3034 (9.3) | 408 (10.3) |  |
Education, n (%) | Â | Â | Â | 0.735 |
 illiteracy | 12,217 (33.4) | 10,878 (33.4) | 1339 (33.7) |  |
 primary school | 10,284 (28.1) | 9196 (28.2) | 1088 (27.4) |  |
 junior high school | 8649 (23.7) | 7704 (23.6) | 945 (23.8) |  |
 senior high school | 3818 (10.4) | 3384 (10.4) | 434 (10.9) |  |
 bachelor or above | 1594 (4.4) | 1422 (4.4) | 172 (4.3) |  |
BMI, mean (SD) | 23.97 (3.43) | 23.80 (3.36) | 25.39 (3.64) |  < 0.001 |
PA, mean (SD) | 24.93 (18.60) | 25.21 (18.64) | 22.65 (18.09) |  < 0.001 |
Smoking status, n (%) |  |  |  |  < 0.001 |
 never | 26,259 (71.8) | 23,604 (72.4) | 2655 (66.7) |  |
 quit | 2384 (6.5) | 2053 (6.3) | 331 (8.3) |  |
 smoke | 7919 (21.7) | 6927 (21.3) | 992 (24.9) |  |
Second-hand smoke, n (%): yes | 17,904 (49.0) | 15,992 (49.1) | 1912 (48.1) | 0.233 |
Alcohol, n (%) |  |  |  |  < 0.001 |
 Never | 21,851 (59.8) | 19,505 (59.9) | 2346 (59.0) |  |
 Occasionally | 8827 (24.1) | 7921 (24.3) | 906 (22.8) |  |
 Often | 5884 (16.1) | 5158 (15.8) | 726 (18.3) |  |
aMED score, mean (SD) | 24.49 (4.51) | 24.52 (4.50) | 24.28 (4.56) |  < 0.005 |
PM10 (µg/m3), mean (SD) | 70.00 (23.32) | 69.79 (23.29) | 71.73 (23.56) |  < 0.001 |
PM2.5 (µg/m3), mean (SD) | 40.45 (15.66) | 40.32 (15.64) | 41.58 (15.73) |  < 0.001 |
PM1 (µg/m3), mean (SD) | 27.62 (6.51) | 27.57 (6.51) | 28.04 (6.48) |  < 0.001 |