Table 1.
Characteristics of the study population according to urine cotinine concentrations in men.
| Total | Nonsmokers | Urine Cotinine Quartiles in Smokers (ng/mL) | |||||
|---|---|---|---|---|---|---|---|
| Q1 (50.00–589.29) | Q2 (589.3–1177.91) | Q3 (1177.92–1826.40) | Q4 (≥1826.41) | p-Value | |||
| N | 8655 | 4814 | 960 | 960 | 959 | 962 | |
| Age (years) | 42.2 (0.2) | 43.9 (0.2) | 43.3 (0.5) | 40.0 (0.4) | 40.9 (0.4) | 41.3 (0.4) | <0.001 |
| Body mass index (kg/m2) | 24.2 (0.0) | 24.3 (0.1) | 24.3 (0.1) | 24.2 (0.1) | 24.2 (0.1) | 23.7 (0.1) | 0.004 |
| Mean arterial pressure (mmHg) | 92.4 (0.2) | 92.7 (0.2) | 91.9 (0.4) | 91.2 (0.4) | 92.3 (0.4) | 92.1 (0.4) | 0.014 |
| Fasting plasma glucose (mg/dl) | 98.8 (0.2) | 99.3 (0.3) | 99.5 (1.1) | 99.5 (0.9) | 98.3 (0.7) | 95.9 (0.6) | <0.001 |
| Triglyceride (mg/dl) | 160.9 (1.7) | 150.5 (2.4) | 159.9 (4.9) | 177.1 (5.0) | 170.8 (6.1) | 183.9 (5.3) | <0.001 |
| HDL cholesterol (mg/dl) | 47.5 (0.2) | 47.7 (0.2) | 48.7 (0.6) | 47.2 (0.6) | 46.6 (0.6) | 46.4 (0.6) | 0.075 |
| Self-reported smoking status (%) | <0.001 | ||||||
| Never smoker | 23.8 (0.5) | 42.9 (0.9) | 5.0 (0.8) | 0.9 (0.3) | 0.2 (0.1) | 0.5 (0.2) | |
| Ex-smoker | 32.7 (0.5) | 54.7 (0.8) | 19.2 (1.5) | 6.5 (1.1) | 3.0 (0.6) | 0.8 (0.2) | |
| Current smoker | 43.5 (0.6) | 2.4 (0.2) | 75.8 (1.7) | 92.6 (1.1) | 96.8 (0.7) | 98.7 (0.4) | |
| Alcohol intake (%) | <0.001 | ||||||
| Non-drinker | 7.8 (0.3) | 10.2 (0.5) | 4.3 (0.7) | 4.2 (0.6) | 6.3 (0.9) | 5.6 (0.8) | |
| Once/week | 54.1 (0.6) | 58.5 (0.9) | 52.3 (1.9) | 54.1 (1.8) | 45.5 (1.9) | 44.6 (1.9) | |
| ≥2 times/week | 38.1 (0.6) | 31.3 (0.8) | 43.4 (1.9) | 41.7 (1.8) | 48.2 (1.9) | 49.8 (1.9) | |
| Regular exercise (%) | 0.532 | ||||||
| None | 48.8 (0.8) | 48.5 (1.2) | 47.1 (2.2) | 49.2 (2.3) | 49.2 (2.2) | 50.7 (2.4) | |
| 1–2 times/week | 23.5 (0.7) | 23.7 (0.9) | 26.3 (1.9) | 24.1 (1.8) | 23.1 (1.8) | 19.5 (1.8) | |
| ≥3 times/week | 27.7 (0.7) | 27.8 (1.0) | 26.6 (1.9) | 26.7 (2.0) | 27.7 (2.1) | 29.8 (2.2) | |
| Education level (%) | <0.001 | ||||||
| ≤middle school | 17.6 (0.5) | 17.8 (0.6) | 15.7 (1.2) | 16.3 (1.4) | 17.1 (1.3) | 19.7 (1.4) | |
| High school | 42.6 (0.7) | 40.6 (0.9) | 40.5 (2.0) | 45.5 (1.9) | 47.0 (1.9) | 47.1 (1.9) | |
| ≥college | 39.8 (0.7) | 41.6 (0.9) | 43.8 (2.1) | 38.2 (1.8) | 35.9 (1.8) | 33.2 (1.9) | |
| Household income (%) | 0.027 | ||||||
| 1st quartile | 10.9 (0.4) | 10.4 (0.5) | 11.6 (1.1) | 12.5 (1.2) | 11.5 (1.1) | 10.4 (1.1) | |
| 2nd quartile | 24.8 (0.6) | 24.1 (0.8) | 24.1 (1.5) | 27.2 (1.7) | 25.0 (1.6) | 25.6 (1.6) | |
| 3rd quartile | 31.3 (0.6) | 30.3 (0.8) | 32.4 (1.9) | 32.0 (1.8) | 31.0 (1.7) | 34.8 (1.8) | |
| 4th quartile | 33.0 (0.8) | 35.2 (1.0) | 31.9 (1.9) | 28.3 (1.7) | 32.5 (1.8) | 29.2 (1.7) | |
| Occupation (%) | <0.001 | ||||||
| Unemployed | 21.0 (0.5) | 24.0 (0.8) | 20.6 (1.6) | 19.8 (1.5) | 15.9 (1.4) | 13.5 (1.3) | |
| Blue-collar workers | 34,.8 (0.7) | 31.7 (0.9) | 30.9 (1.7) | 35.0 (1.8) | 41.7 (1.9) | 46.0 (1.9) | |
| White-collar workers | 44.2 (0.7) | 44.3 (0.9) | 48.5 (1.9) | 45.2 (1.9) | 42.4 (1.9) | 40.5 (1.9) | |
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.