Table 1.
Characteristics of the participants by serum cotinine level quartile.
| Variables |
Quartile 1 ≤0.01 ng/ml (n = 1,203) |
Quartile 2 0.01 < cotinine ≤ 0.02 ng/ml (n = 451) |
Quartile 3 0.02 < cotinine ≤ 0.04 ng/ml (n = 398) |
Quartile 4 >0.04 ng/ml (n = 651) |
Total (n = 2,703) |
|---|---|---|---|---|---|
| Age, years | 71.0 (65.0, 79.0) | 69.0 (64.0, 78.0) | 69.0 (63.0, 75.3) | 68.0 (63.0, 76.0) | 70.0 (64.0, 78.0) |
| Sex, n (%) | |||||
| Male | 516 (42.9%) | 216 (47.9%) | 189 (47.5%) | 332 (51.0%) | 1,253 (46.4%) |
| Female | 687 (57.1%) | 235 (52.1%) | 209 (52.5%) | 319 (49.0%) | 1,450 (53.6%) |
| Race/ethnicity, n (%) | |||||
| Mexican Americans | 123 (10.2%) | 49 (10.9%) | 28 (7.0%) | 49 (7.5%) | 249 (9.2%) |
| Other Hispanics | 123 (10.2%) | 55 (12.2%) | 50 (12.6%) | 43 (6.6%) | 271 (10.0%) |
| Non-Hispanic Whites | 717 (59.6%) | 182 (40.4%) | 163 (41.0%) | 243 (37.3%) | 1,305 (48.3%) |
| Non-Hispanic Blacks | 148 (12.3%) | 98 (21.7%) | 87 (21.9%) | 225 (34.6%) | 558 (20.6%) |
| Other | 92 (7.6%) | 67 (14.9%) | 70 (17.6%) | 91 (14.0%) | 320 (11.8%) |
| Education, n (%) | |||||
| Below high school | 256 (21.3%) | 133 (29.5%) | 112 (28.2%) | 222 (34.2%) | 723 (26.7%) |
| High school graduate | 247 (20.5%) | 96 (21.3%) | 106 (26.7%) | 172 (26.5%) | 621 (23.0%) |
| Some college or above | 699 (58.2%) | 222 (49.2%) | 179 (45.1%) | 255 (39.3%) | 1,355 (50.1%) |
| Alcoholic drinks/day, n (%) | |||||
| 0–1 drink | 393 (63.8%) | 144 (65.2%) | 116 (60.1%) | 140 (46.4%) | 793 (29.3%) |
| 2 drinks | 164 (26.6%) | 47 (21.3%) | 45 (23.3%) | 83 (27.5%) | 339 (12.5%) |
| 3 or more drinks | 59 (9.6%) | 30 (13.6%) | 32 (16.6%) | 79 (26.2%) | 200 (7.4%) |
| Depressive symptoms | 2.0 (0.0, 4.0) | 1.0 (0.0, 4.0) | 2.0 (0.0, 5.0) | 1.0 (0.0, 5.0) | 1.0 (0.0, 4.0) |
| Total cholesterol, mg/dL | 190.0 (162.0, 218.0) | 185.0 (156.0, 218.0) | 188.0 (159.0, 218.5) | 186.0 (161.0, 213.0) | 188.0 (161.0, 217.0) |
| Systolic blood pressure, mmHg | 131.3 (120.0, 143.3) | 132.0 (119.3, 142.7) | 129.3 (117.8, 142.0) | 131.3 (120.7, 144.7) | 131.3 (120.0, 143.3) |
| Frailty, n (%) | |||||
| Robust | 369 (38.3%) | 142 (39.3%) | 138 (45.0%) | 155 (32.8%) | 804 (29.7%) |
| Pre-frail | 524 (54.4%) | 194 (53.7%) | 148 (48.2%) | 262 (55.5%) | 1,128 (41.7%) |
| Frail | 71 (7.4%) | 25 (6.9%) | 21 (6.8%) | 55 (11.7%) | 172 (6.4%) |
Data was presented as median (interquartile range) for continuous variables and n (%) for categorical variables.