Table 3.
Odds ratios (95% CI) of BMI-defined obesity associated with each 10 μg/m3 increase of SO2, NO2, O3, PM1, PM2.5, PM10, stratified by demographic and lifestyle factors.
| Effect modifiersa | SO2 | NO2 | O3 | PM1 | PM2.5 | PM10 | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| OR (95% CI) | p valueb | OR (95% CI) | p value | OR (95% CI) | p value | OR (95% CI) | p value | OR (95% CI) | p value | OR (95% CI) | p value | |
| Main analyses | 1.21 (1.17, 1.26) | – | 1.33 (1.26, 1.40) | – | 1.15 (1.10, 1.21) | – | 1.38 (1.29, 1.48) | – | 1.19 (1.15, 1.22) | – | 1.11 (1.10, 1.13) | – |
| Gender | ||||||||||||
| Male | 1.21 (1.14, 1.29) | Ref. | 1.27 (1.17, 1.38) | Ref. | 1.07 (0.99, 1.16) | Ref. | 1.39 (1.24, 1.56) | Ref. | 1.18 (1.13, 1.23) | Ref. | 1.11 (1.08, 1.13) | Ref. |
| Female | 1.21 (1.15, 1.27) | 0.683 | 1.36 (1.27, 1.45) | 0.267 | 1.21 (1.14, 1.28) | 0.026 | 1.38 (1.27, 1.51) | 0.877 | 1.19 (1.15, 1.23) | 0.707 | 1.11 (1.09, 1.14) | 0.494 |
| Age | ||||||||||||
| Middle-aged (45 - 64 years) | 1.21 (1.16, 1.27) | Ref. | 1.28 (1.21, 1.36) | Ref. | 1.14 (1.08, 1.21) | Ref. | 1.33 (1.23, 1.44) | Ref. | 1.17 (1.13, 1.20) | Ref. | 1.10 (1.08, 1.12) | Ref. |
| Elderly (65 years and above) | 1.21 (1.11, 1.31) | 0.745 | 1.50 (1.35, 1.67) | 0.008 | 1.19 (1.08, 1.31) | 0.403 | 1.60 (1.37, 1.87) | 0.028 | 1.26 (1.19, 1.33) | 0.032 | 1.15 (1.12, 1.19) | 0.019 |
| Educational attainment | ||||||||||||
| Middle school or below | 1.20 (1.15, 1.25) | Ref. | 1.35 (1.28, 1.43) | Ref. | 1.17 (1.11, 1.23) | Ref. | 1.41 (1.31, 1.52) | Ref. | 1.19 (1.16, 1.23) | Ref. | 1.12 (1.10, 1.14) | Ref. |
| High school or above | 1.29 (1.15, 1.44) | 0.192 | 1.20 (1.04, 1.37) | 0.094 | 1.04 (0.92, 1.18) | 0.104 | 1.24 (1.02, 1.51) | 0.214 | 1.15 (1.06, 1.24) | 0.415 | 1.08 (1.04, 1.13) | 0.24 |
| Smoking status | ||||||||||||
| Non-smoker | 1.20 (1.12, 1.30) | Ref. | 1.26 (1.14, 1.38) | Ref. | 1.07 (0.99, 1.17) | Ref. | 1.34 (1.17, 1.53) | Ref. | 1.14 (1.09, 1.20) | Ref. | 1.09 (1.06, 1.12) | Ref. |
| Smoker | 1.19 (1.12, 1.27) | 0.851 | 1.30 (1.19, 1.43) | 0.621 | 1.08 (1.00, 1.17) | 0.919 | 1.39 (1.23, 1.58) | 0.739 | 1.20 (1.14, 1.26) | 0.228 | 1.12 (1.09, 1.15) | 0.193 |
| Second-hand Smoker | 1.23 (1.16, 1.31) | 0.455 | 1.40 (1.29, 1.52) | 0.107 | 1.28 (1.19, 1.38) | 0.004 | 1.42 (1.27, 1.58) | 0.593 | 1.21 (1.15, 1.26) | 0.103 | 1.12 (1.10, 1.15) | 0.061 |
| Drinking status | ||||||||||||
| Non-drinker | 1.21 (1.16, 1.27) | Ref. | 1.34 (1.26, 1.43) | Ref. | 1.19 (1.12, 1.26) | Ref. | 1.40 (1.29, 1.52) | Ref. | 1.20 (1.16, 1.24) | Ref. | 1.12 (1.10, 1.14) | Ref. |
| Drink but less than once a month | 1.13 (0.98, 1.30) | 0.344 | 1.27 (1.05, 1.54) | 0.58 | 1.11 (0.93, 1.33) | 0.503 | 1.18 (0.92, 1.51) | 0.167 | 1.12 (1.02, 1.24) | 0.238 | 1.07 (1.01, 1.13) | 0.159 |
| Drink more than once a month | 1.23 (1.13, 1.35) | 0.801 | 1.29 (1.15, 1.44) | 0.71 | 1.06 (0.96, 1.17) | 0.081 | 1.42 (1.21, 1.66) | 0.685 | 1.17 (1.10, 1.24) | 0.544 | 1.11 (1.07, 1.15) | 0.707 |
BMI, body mass index; 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.
aThe effects were estimated by logistic regression models with adjustment for gender, age, educational attainment, smoking status and drinking status. All stratified estimates were adjusted for the remaining covariates.
bP values represent the interaction effects between air pollutants and possible modifiers.