Table 1.
Baseline characteristics of participants stratified by severity of percent emphysema.
| Percent Emphysema
|
|||||
|---|---|---|---|---|---|
| Quintile 1 (n=728) | Quintile 2 (n=729) | Quintile 3 (n=728) | Quintile 4 (n=729) | Quintile 5 (n=728) | |
| Age, mean (SD), years | 60 (10) | 61 (10) | 61 (10) | 62 (10) | 63 (10) |
| Male gender, No. (%) | 164 (23) | 263 (36) | 350 (48) | 454 (62) | 554 (76) |
| Race/ethnicity | |||||
| White, No. (%) | 132 (18) | 213 (29) | 242 (33) | 301 (41) | 391 (54) |
| African American, No. (%) | 217 (30) | 181 (25) | 189 (26) | 193 (26) | 185 (25) |
| Hispanic, No. (%) | 234 (32) | 199 (27) | 154 (21) | 136 (19) | 84 (12) |
| Asian, No. (%) | 145 (20) | 136 (19) | 143 (20) | 99 (14) | 68 (9) |
| Educational attainment | |||||
| No high school degree, No. (%) | 200 (27) | 141 (19) | 122 (17) | 81 (11) | 62 (9) |
| High school degree, No. (%) | 162 (22) | 146 (20) | 123 (17) | 118 (16) | 109 (15) |
| Some college, No. (%) | 206 (28) | 210 (29) | 206 (28) | 207 (28) | 184 (25) |
| College degree, No. (%) | 88 (12) | 119 (16) | 129 (18) | 164 (22) | 167 (23) |
| ≥bachelor degree, No. (%) | 71 (10) | 113 (15) | 148 (20) | 159 (22) | 203 (28) |
| Body mass index, mean (SD), kg/m2 | 29.3 (5.8) | 28.5 (5.7) | 27.8 (5.0) | 27.5 (4.7) | 26.4 (4.1) |
| Cigarette smoking status | |||||
| Never, No. (%) | 405 (56) | 363 (50) | 351 (48) | 335 (46) | 263 (36) |
| Former, No. (%) | 191 (26) | 242 (33) | 282 (39) | 308 (42) | 389 (53) |
| Current, No. (%) | 132 (18) | 124 (17) | 95 (13) | 86 (12) | 76 (10) |
| Pack-years of smoking, median (IQR)* | 17 (5, 33) | 19 (7, 38) | 15 (6, 33) | 20 (7, 38) | 17 (6, 35) |
| Hypertension, No. (%) | 324 (45) | 323 (44) | 320 (44) | 282 (39) | 287 (39) |
| Systolic blood pressure, mean (SD), mmHg | 125 (21) | 125 (20) | 125 (20) | 124 (19) | 123 (18) |
| Diastolic blood pressure, mean (SD), mmHg | 70 (10) | 71 (10) | 72 (10) | 72 (10) | 73 (10) |
| Diabetes mellitus, No. (%) | 108 (15) | 85 (12) | 74 (10) | 69 (9) | 46 (6) |
| Fasting plasma glucose, median (IQR), mg/dL | 98 (90, 108) | 96 (89, 105) | 96 (90, 105) | 96 (90, 105) | 95 (90, 102) |
| LDL, mean (SD), mg/dL | 118 (30) | 116 (31) | 117 (30) | 119 (32) | 117 (30) |
| HDL, mean (SD), mg/dL | 51 (14) | 52 (15) | 51 (15) | 51 (15) | 50 (14) |
| Use of statin, No. (%) | 89 (12) | 111 (15) | 96 (13) | 104 (14) | 116 (16) |
| C-reactive protein, median (IQR), mg/L | 2.3 (1.1, 5.7) | 1.9 (0.8, 4.3) | 1.7 (0.9, 3.7) | 1.7 (0.8, 3.6) | 1.2 (0.6, 2.8) |
| Self-reported asthma < age 45 years, No. (%) | 50 (7) | 54 (7) | 51 (7) | 64 (8) | 67 (9) |
| Self-reported asthma ≥ age 45 years, No. (%) | 11 (1) | 8 (1) | 12 (2) | 12 (2) | 19 (3) |
| FEV1 percent of predicted, mean (SD) | 96 (15) | 96 (16) | 96 (17) | 96 (18) | 95 (20) |
| FVC percent of predicted, mean (SD) | 94 (14) | 96 (14) | 97 (15) | 99 (15) | 102 (16) |
| FEV1/FVC ratio, mean (SD), % | 78 (7) | 76 (7) | 75 (8) | 73 (9) | 70 (10) |
| Percent emphysema, median (IQR), | 3.4 (1.8, 4.8) | 8.9 (7.6, 10.3) | 14.7 (13.2, 16.5) | 22.1 (20.0, 24.8) | 34.3 (30.3, 40.8) |
| Upper-lobe emphysema (ratio), median (IQR) | 1.08 (0.57, 1.93) | 1.09 (0.76, 1.67) | 1.11 (0.85, 1.46) | 1.04 (0.81, 1.33) | 1.02 (0.88, 1.18) |
*
Packyears of smoking among ever smokers
SD = Standard deviation; IQR = Interquartile range; MRC = Medical Research Council; FEV1 = Forced expiratory volume in one second; FVC = Forced vital capacity.