Table 2.
(A). Comparison of baseline exhaled CO concentration between different groups in smokers. (B). Comparison of exhaled CO half-life between different groups in smokers.
| (A) | ||
| Variable (n = 48) | Baseline Exhaled CO (ppm) | p-Value |
| Mean ± SD 1 | ||
| Total (n = 48) | 5.2 ± 4.6 | |
| Gender | 0.002 ** | |
| Male (n = 39) | 7.7 ± 5.1 | |
| Female (n = 9) | 3.6 ± 2.1 | |
| Smoking status | <0.001 ** | |
| Light smokers (n = 28) | 4.8 ± 2.6 | |
| Heavy smokers (n = 20) | 10.0 ± 5.8 | |
| Ethnicity | 0.264 | |
| Asian (n = 27) | 7.9 ± 5.9 | |
| Black/African-American (n = 1) | 9 | |
| Hispanic/Latino (n = 2) | 5.0 ± 4.2 | |
| White/Caucasian (n = 16) | 5.9 ± 3.0 | |
| Mixed ethnicity (n = 2) | 2.5 ± 0.7 | |
| Type of cigarette | 0.744 | |
| Factory-made cigarette (n = 33) | 7.3 ± 1.0 | |
| Hand-rolled cigarette (n = 11) | 5.7 ± 0.8 | |
| Both (n = 4) | 7.0 ± 1.4 | |
| Exposure to CO before the study | 0.094 | |
| None (n = 32) | 7.8 ± 1.0 | |
| Yes (n = 16) | 5.3 ± 0.7 | |
| Exercise before study | 0.586 | |
| None (n = 30) | 6.6 ± 0.8 | |
| Yes (n = 18) | 7.4 ± 1.4 | |
| (B) | ||
| Variable (n = 45) | CO Half-Life (Minutes) | p-Value |
| Mean ± SD 1 | ||
| Total (n = 45) | 273.3 ± 95.6 | |
| Gender | 0.010 * | |
| Male (n = 36) | 288.1 ± 96.1 | |
| Female (n = 9) | 213.9 ± 70.4 | |
| Smoking status | 0.396 | |
| Light smokers (n = 25) | 262.3 ± 90.5 | |
| Heavy smokers (n = 20) | 287.0 ± 22.9 | |
| Ethnicity | 0.462 | |
| Asian (n = 25) | 282.8 ± 101.8 | |
| Black/African-American (n = 1) | 314.4 | |
| Hispanic/Latino (n = 2) | 205.8 ± 52.8 | |
| White/Caucasian (n = 15) | 272.7 ± 95.4 | |
| Mixed Ethnicity (n = 2) | 206.1 ± 35.6 | |
| Type of cigarette | 0.848 | |
| Factory-made cigarette (n = 31) | 272.3 ± 93.6 | |
| Hand-rolled cigarette (n = 10) | 280.1 ± 123.2 | |
| Both (n = 4) | 264.5 ± 27.1 | |
| Exposure CO before the study | 0.281 | |
| None (n = 29) | 284.8 ± 106.5 | |
| Yes (n = 16) | 252.4 ± 70.2 | |
| Exercise before the study | 0.486 | |
| None (n = 29) | 280.8 ± 94.4 | |
| Yes (n = 16) | 259.7 ± 99.3 | |
1 SD—standard deviation. Where a significant difference between groups was found, the p-values are highlighted: * p-value <0.05; ** p-value <0.01.