Table 1.
Characteristics of the participants according to the presence of BMI-defined obesity.
| Characteristicsa | level | Overall (n = 11,766) | Non-obesity (n = 10,205) | Obesity (n = 1,561) | p value |
|---|---|---|---|---|---|
| Demographics | |||||
| Age, years | 60.00 [52.00, 67.00] | 60.00 [52.00, 67.00] | 57.00 [51.00, 64.00] | <0.001* | |
| Age group | Middle-aged (45 - 64 years) | 7985 (67.87) | 6781 (66.45) | 1204 (77.13) | <0.001* |
| Elderly (65 years and above) | 3781 (32.13) | 3424 (33.55) | 357 (22.87) | ||
| Gender | Male | 5553 (47.20) | 4984 (48.84) | 569 (36.45) | <0.001* |
| Female | 6213 (52.80) | 5221 (51.16) | 992 (63.55) | ||
| Education level | Middle school or below | 8989 (88.01) | 7797 (87.88) | 1192 (88.82) | 0.346 |
| High school or above | 1225 (11.99) | 1075 (12.12) | 150 (11.18) | ||
| Residence | Rural | 7288 (61.94) | 6418 (62.89) | 870 (55.73) | <0.001* |
| Urban | 4478 (38.06) | 3787 (37.11) | 691 (44.27) | ||
| Lifestyle behaviors | |||||
| Smoking Status | Non-smoker | 3132 (26.62) | 2675 (26.21) | 457 (29.28) | <0.001* |
| Smoker | 4877 (41.45) | 4392 (43.04) | 485 (31.07) | ||
| Second-hand Smoker | 3757 (31.93) | 3138 (30.75) | 619 (39.65) | ||
| Drinking Status | Non-drinker | 7617 (64.74) | 6504 (63.73) | 1113 (71.30) | <0.001* |
| Drink but less than once a month | 1033 (8.78) | 911 (8.93) | 122 (7.82) | ||
| Drink more than once a month | 3116 (26.48) | 2790 (27.34) | 326 (20.88) | ||
| Clinical characteristics | |||||
| SBP, mmHg | 126.67 [114.33, 141.33] | 125.33 [113.67, 140.33] | 132.67 [121.67, 145.67] | <0.001* | |
| DBP, mmHg | 74.67 [67.67, 82.67] | 74.00 [67.00, 81.67] | 79.33 [72.00, 87.00] | <0.001* | |
| Pulse, bpm | 73.00 [66.33, 80.00] | 73.00 [66.33, 80.00] | 74.33 [67.58, 81.00] | <0.001* | |
| BMI, kg/m2 | 23.67 [21.35, 26.25] | 23.09 [20.94, 25.09] | 29.64 [28.73, 31.25] | <0.001* | |
| Waistline, cm | 86.05 [79.00, 93.40] | 84.40 [78.00, 90.60] | 101.20 [96.50, 105.60] | <0.001* | |
| Laboratory measures | |||||
| FBG, mmol/L | 5.31 [4.90, 5.91] | 5.31 [4.90, 5.81] | 5.51 [5.11, 6.31] | <0.001* | |
| Tch, mmol/L | 4.68 [4.12, 5.32] | 4.67 [4.10, 5.30] | 4.83 [4.26, 5.50] | <0.001* | |
| TG, mmol/L | 1.30 [0.94, 1.93] | 1.25 [0.91, 1.83] | 1.76 [1.25, 2.64] | <0.001* | |
| LDL, mmol/L | 2.61 [2.14, 3.10] | 2.59 [2.13, 3.08] | 2.69 [2.23, 3.20] | <0.001* | |
| HDL, mmol/L | 1.29 [1.12, 1.49] | 1.31 [1.13, 1.51] | 1.20 [1.05, 1.35] | <0.001* | |
| Comorbidities | |||||
| Hypertension | No | 8508 (72.31) | 7664 (75.10) | 844 (54.07) | <0.001* |
| Yes | 3258 (27.69) | 2541 (24.90) | 717 (45.93) | ||
| Diabetes | No | 10895 (92.60) | 9524 (93.33) | 1371 (87.83) | <0.001* |
| Yes | 871 (7.40) | 681 (6.67) | 190 (12.17) | ||
| Cardiac disease | No | 10193 (86.63) | 8972 (87.92) | 1221 (78.22) | <0.001* |
| Yes | 1573 (13.37) | 1233 (12.08) | 340 (21.78) | ||
| Stroke | No | 11547 (98.14) | 10028 (98.27) | 1519 (97.31) | 0.012* |
| Yes | 219 (1.86) | 177 (1.73) | 42 (2.69) | ||
| Outdoor & indoor air pollution exposure | |||||
| SO2, μg/m3 | 23.95 [16.37, 36.22] | 23.77 [16.37, 34.65] | 26.93 [20.29, 42.42] | <0.001* | |
| NO2, μg/m3 | 30.22 [21.84, 38.12] | 29.81 [21.77, 37.92] | 33.83 [25.68, 42.93] | <0.001* | |
| O3, μg/m3 | 81.43 [74.94, 92.30] | 81.19 [74.51, 91.57] | 82.53 [75.89, 93.08] | <0.001* | |
| PM1, μg/m3 | 35.38 [31.53, 41.08] | 35.26 [31.53, 40.92] | 38.01 [32.00, 43.98] | <0.001* | |
| PM2.5, μg/m3 | 52.20 [39.62, 64.34] | 51.83 [39.31, 63.77] | 56.69 [42.44, 76.72] | <0.001* | |
| PM10, μg/m3 | 86.69 [62.68, 106.49] | 85.48 [62.68, 105.37] | 95.43 [75.54, 131.23] | <0.001* | |
| Fuel | Clean fuel use | 6108 (51.91) | 5310 (52.03) | 798 (51.12) | 0.519 |
| Solid fuel use | 5658 (48.09) | 4895 (47.97) | 763 (48.88) | ||
BMI, body mass index; SBP, systolic blood pressure; DBP, diastolic blood pressure; FBG, fast blood glucose; Tch, total cholesterol; TG, triglyceride; LDL, low density lipoprotein; HDL, high density lipoprotein; SO2, sulfur dioxide; NO2, nitrogen dioxide; O3, ozone; PM1, particulate matter with aerodynamic diameters of ≤1 μm; PM2.5, particulate matter with aerodynamic diameters of ≤ 2.5 μm; PM10, particulate matter with aerodynamic diameters of ≤ 10 μm.
aData are presented as median and the interquartile range (IQR) for continuous variables and counts (percentages) for categorical variables. Examining differences between obesity and non-obesity based on Kruskal-Wallis tests for continuous variables and Chi-squared tests for categorical variables.
*P values <0.05 (two-tailed) were considered statistically significant.