Table 2.
Characteristics of the study population according to urine cotinine concentrations in women.
| Total | Nonsmokers | Urine Cotinine Quartiles in Smokers (ng/mL) | |||||
|---|---|---|---|---|---|---|---|
| Q1 (50.00–162.79) | Q2 (162.80–556.62) | Q3 (556.63–1073.13) | Q4 (≥1073.14) | p-value | |||
| N | 10,342 | 9,329 | 275 | 276 | 276 | 276 | |
| Age (years) | 44.6 (0.2) | 45.1 (0.2) | 41.0 (1.0) | 38.4 (1.0) | 40.1 (0.9) | 42.1 (0.9) | <0.001 |
| Body mass index (kg/m2) | 23.1 (0.0) | 23.1 (0.0) | 23.1 (0.3) | 22.7 (0.2) | 22.9 (0.2) | 22.2 (0.2) | 0.004 |
| Mean arterial pressure (mmHg) | 86.3 (0.2) | 86.5 (0.1) | 84.8 (0.7) | 84.9 (0.8) | 85.1 (0.7) | 84.8 (0.7) | 0.004 |
| Fasting plasma glucose (mg/dl) | 95.1 (0.2) | 95.3 (0.2) | 94.4 (1.1) | 93.8 (1.0) | 94.6 (1.2) | 93.4 (1.1) | 0.313 |
| Triglyceride (mg/dl) | 108.6 (0.9) | 107.3 (0.8) | 106.9 (5.9) | 116.7 (5.9) | 121.5 (5.2) | 129.1 (7.0) | <0.001 |
| HDL cholesterol (mg/dl) | 54.7 (0.2) | 54.6 (0.2) | 55.2 (1.9) | 56.4 (1.3) | 55.9 (1.4) | 55.1 (1.2) | 0.519 |
| Self-reported current smoking (%) | <0.001 | ||||||
| Never smoker | 87.5 (0.4) | 93.7 (0.3) | 74.2 (3.4) | 36.5 (3.4) | 27.0 (3.1) | 26.3 (3.3) | |
| Ex-smoker | 6.4 (0.3) | 5.9 (0.3) | 11.5 (2.3) | 13.8 (2.6) | 7.1 (1.8) | 7.8 (1.8) | |
| Current smoker | 6.1 (0.3) | 0.4 (0.1) | 14.4 (2.9) | 49.7 (3.6) | 65.9 (3.4) | 65.9 (3.4) | |
| Alcohol intake (%) | <0.001 | ||||||
| Non-drinker | 18.4 (0.5) | 19.4 (0.5) | 11.5 (2.2) | 9.2 (1.7) | 18.0 (2.6) | 8.1 (1.9) | |
| Once/week | 68.8 (0.6) | 70.0 (0.6) | 65.8 (3.6) | 59.3 (3.3) | 57.8 (3.6) | 58.4 (3.6) | |
| ≥2 times/week | 12.8 (0.4) | 10.5 (0.4) | 22.7 (3.3) | 31.5 (3.1) | 24.2 (3.1) | 33.5 (3.5) | |
| Regular exercise (%) | 0.758 | ||||||
| None | 59.7 0.9) | 59.7 (0.9) | 58.9 (3.6) | 59.3 (4.2) | 55.3 (4.2) | 63.2 (4.3) | |
| 1–2 times/week | 15.8 (0.6) | 15.9 (0.6) | 18.7 (2.8) | 14.1 (3.0) | 14.3 (3.2) | 14.6 (3.4) | |
| ≥3 times/week | 24.5 (0.8) | 24.4 (0.8) | 22.4 (3.0) | 26.6 (3.7) | 30.4 (3.7) | 22.2 (3.6) | |
| Education level (%) | <0.001 | ||||||
| ≤middle school | 29.4 (0.6) | 30.1 (0.6) | 23.9 (2.9) | 18.0 (2.9) | 27.3 (2.8) | 29.8 (3.0) | |
| High school | 38.4 (0.7) | 33.7 (0.6) | 42.8 (3.5) | 53.5 (3.6) | 53.8 (3.5) | 52.1 (3.4) | |
| ≥college | 32.2 (0.7) | 33.2 (0.7) | 33.3 (3.5) | 28.5 (3.3) | 18.9 (2.7) | 18.0 (2.7) | |
| Household income (%) | <0.001 | ||||||
| 1st quartile | 14.9 (0.4) | 14.8 (0.4) | 13.8 (2.3) | 13.8 (2.3) | 16.6 (2.4) | 19.8 (2.6) | |
| 2nd quartile | 26.0 (0.6) | 25.1 (0.6) | 30.9 (3.3) | 30.5 (3.3) | 34.3 (3.5) | 36.1 (3.4) | |
| 3rd quartile | 28.8 (0.6) | 29.4 (0.6) | 23.2 (2.8) | 24.8 (3.2) | 21.0 (2.7) | 24.4 (3.2) | |
| 4th quartile | 30.3 (0.8) | 30.6 (0.8) | 32.1 (3.4) | 30.9 (3.3) | 28.1 (3.7) | 19.7 (2.9) | |
| Occupation (%) | 0.714 | ||||||
| Unemployed | 45.9 (0.6) | 48.2 (0.6) | 46.2 (3.6) | 46.7 (3.6) | 45.7 (3.6) | 43.3 (3.5) | |
| Blue-collar workers | 15.7 (0.5) | 15,7 (0.5) | 15.3 (2.3) | 12.3 (2.3) | 15.7 (3.3) | 17.8 (2.6) | |
| White-collar workers | 35.4 (0.6) | 36.1 (0.6) | 38.5 (3.7) | 41.0 (3.5) | 38.6 (3.4) | 38.9 (3.5) | |
Data are expressed as the mean (SE) or percentage (SE). p values were calculated using weighted one-way ANOVA test or weighted chi-square test.