Table 3.
Association between smoking status, serum cotinine concentrations, and risk of kidney stones.
| Exposure | OR (95% CI), P | |||
|---|---|---|---|---|
| Model 1 | Model 2 | Model 3 | Model 4 | |
| Smoking status, category | ||||
| Non-smokers | Ref | Ref | Ref | Ref |
| Former smokers | 1.08 (0.99, 1.18), 0.095 | 1.07 (0.97, 1.18), 0.182 | 1.06 (0.96, 1.17), 0.288 | 1.05 (0.96, 1.15), 0.249 |
| Current smokers | 1.19 (1.07, 1.32), <0.001 | 1.18 (1.05, 1.31), 0.004 | 1.17 (1.04, 1.31), 0.009 | 1.16 (1.05, 1.28), 0.005 |
| P for trend | <0.001 | 0.004 | 0.010 | - |
| Serum cotinine concentrations | ||||
| Log2-transformed serum cotinine (ng/ml) | 1.02 (1.01, 1.03), <0.001 | 1.02 (1.01, 1.03), <0.001 | 1.02 (1.01, 1.03), <0.001 | 1.02 (1.01, 1.03), <0.001 |
| Cotinine level, category | ||||
| <0.05 ng/ml | Ref | Ref | Ref | Ref |
| 0.05–2.99 ng/ml | 1.16 (1.04, 1.28), 0.005 | 1.16 (1.04, 1.30), 0.006 | 1.15 (1.03, 1.29), 0.013 | 1.15 (1.04, 1.28), 0.007 |
| ≥3.00 ng/ml | 1.25 (1.14, 1.38), <0.001 | 1.25 (1.12, 1.39), <0.001 | 1.22 (1.10, 1.37), <0.001 | 1.23 (1.11, 1.36), <0.001 |
| P for trend | <0.001 | <0.001 | <0.001 | - |
Model 1 adjusted age, sex, race, and BMI; Model 2 adjusted for Model 1 plus marital status, education, family PIR, and physical activity; Model 3 adjusted for Model 2 plus serum uric acid, hypertension, coronary heart disease, diabetes, and gout; Model 4 represented the effect values integrated after MI based on Model 3.