Table 2 Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) of metabolic syndrome associated with cigarette smoking
Cigarette smoking variables | Discovery stage: TNCHS studya | Replication stage: CHNS studyb | ||||
|---|---|---|---|---|---|---|
MetS ( +)/All | OR (95%Cl) | P trend c | MetS ( +)/All | OR (95%Cl) | P trend c | |
Non-smoker | 3,063/13,739 | Reference |  | 1,047/5,977 | Reference | – |
Smoking status |  |  | - |  |  | – |
 Ever-smoker | 483/1,483 | 1.62 (1.43–1.84) | 512/2588 | 1.18 (0.10–1.40) | ||
 Former | 28/90 | 1.11 (0.68–1.80) | 46/187 | 0.85 (0.57–1.27) | ||
 Current | 455/1,393 | 1.66 (1.46–1.89) | 466/2401 | 1.22 (1.03–1.45) | ||
Intensity of smoking (cig/day)d |  |  |  < 0.001 |  |  | 0.015 |
 1–9 | 90/357 | 1.10 (0.85–1.43) | 81/427 | 1.05 (0.77–1.42) | ||
 10–19 | 186/535 | 1.73 (1.42–2.11) | 131/709 | 1.09 (0.85–1.40) | ||
 20- | 207/591 | 1.91 (1.58–2.31) | 300/1,452 | 1.27 (1.05–1.54) | ||
Smoking durationd |  |  |  < 0.001 |  |  | 0.881 |
 Tertile 1 | 143/471 | 1.46 (1.17–1.82) | 156/846 | 1.51 (1.18–1.93) | ||
 Tertile 2 | 154/468 | 1.72 (1.39–2.14) | 197/882 | 1.41 (1.13–1.76) | ||
 Tertile 3 | 186/544 | 1.68 (1.38–2.05) | 159/860 | 0.81 (0.64–1.03) | ||
Pack-yearsd |  |  |  < 0.001 |  |  | 0.639 |
 Tertile 1 | 132/494 | 1.18 (0.94–1.46) | 160/869 | 1.25 (0.99–1.58) | ||
 Tertile 2 | 172/494 | 1.81 (1.47–2.22) | 172/830 | 1.30 (1.04–1.64) | ||
 Tertile 3 | 179/495 | 1.97 (1.61–2.42) | 180/889 | 1.03 (0.82–1.29) | ||
CSI categoriesd |  |  |  < 0.001 |  |  | 0.364 |
 Tertile 1 | 132/494 | 1.19 (0.95–1.48) | 161/862 | 1.30 (1.03–1.65) | ||
 Tertile 2 | 168/502 | 1.76 (1.44–2.16) | 181/869 | 1.30 (1.04–1.63) | ||
 Tertile 3 | 183/487 | 2.01 (1.64–2.47) | 170/857 | 0.99 (0.78–1.24) | ||