Table 1.
Characteristics of the study population.
| Characteristic | All Participants (n = 54) |
|---|---|
| Age, years—mean ± SD | 73.3 ± 7.4 |
| Female—N (%) | 22 (40.7%) |
| Race/Ethnicity—N (%) | |
| White | 28 (51.9%) |
| Black | 17 (31.5%) |
| Hispanic | 9 (16.6%) |
| Height, cm—mean ± SD | 175.8 ± 4.8 |
| Weight, lb—mean ± SD | 75.8 ± 14.2 |
| Smoking status—N (%) | |
| Former smoker | 38 (70.4%) |
| Current smoker | 16 (29.6%) |
| Pack-years—mean ± SD | 41.3 ± 23.0 |
| Educational attainment—N (%) | |
| <High school degree | 15 (27.8%) |
| College degree | 24 (44.4%) |
| Some college/2-year degree | 15 (27.8%) |
| Spirometry (post-bronchodilator) | |
| FEV1 (mL)—mean ± SD, n = 53 | 2157 ± 577 |
| FVC (mL)—mean ± SD, n = 53 | 3326 ± 965 |
| FEV1/FVC—mean ± SD, n = 53 | 0.67 ± 0.13 |
| COPD—No. (%) | 29 (53.7%) |
| COPD severity—N (%) | |
| None | 25 (46.3%) |
| Mild | 13 (24.1%) |
| Moderate | 16 (29.6%) |
| CT measures | |
| Total lung volume (mL)—mean ± SD | 5460 ± 1353 |
| Total tissue volume (mL)—mean ± SD | 835 ± 176 |
| Total air volume (mL)—mean ± SD | 4625 ± 1220 |
| % emphysema −950 HU—median [IQR] | 2.1 [0.9, 7.1] |
| Visual emphysema severity (%) 1—median [IQR] | 0.24 [0, 2.31] |
| DLCO measures, n = 34 | |
| DLCO (%)—mean ± SD | 18.1 ± 4.9 |
| 3He MRI measures | |
| pAO2 mean (bar)—median [IQR] | 0.093 [0.084, 0.103] |
| pAO2 SD (bar)—median [IQR] | 0.052 [0.037, 0.064] |
| pAO2 %negative—median [IQR] | 4.9 [2.1, 7.5] |
| ADC mean (cm2/s)—median [IQR] | 0.302 [0.267, 0.383] |
1 Calculated as the sum of the severity scores for centrilobular, panlobular, and paraseptal emphysema; DLCO, diffusing capacity of carbon monoxide. COPD status was defined as: post-bronchodilator FEV1/FVC < 0.7. COPD severity was defined as: Mild: %-predicted FEV1 ≥ 80; Moderate: 50 ≤ %-predicted FEV1 < 80.