Table 5.
Regional associations between percent emphysema or pulmonary emphysema subtype severity and pAO2 measures.
| pAO2 Mean | pAO2 SD | pAO2 %Negative | ||||
|---|---|---|---|---|---|---|
| Exposure | β (95% CI) | p | β (95% CI) | p | β (95% CI) | p |
| %emphysema, log-transformed 1 | ||||||
| Unadjusted (n = 54) | 0.0001 (−0.003, 0.003) | 0.94 | 0.0006 (−0.002, 0.003) | 0.61 | 0.43 (−0.44, 1.30) | 0.33 |
| Model 1 (n = 54) | 0.0008 (−0.002, 0.004) | 0.59 | 0.00002 (−0.002, 0.002) | 0.99 | 0.15 (−0.71, 1.01) | 0.73 |
| Model 2 (n = 53) | 0.001 (−0.002, 0.004) | 0.39 | −0.0004 (−0.003, 0.002) | 0.74 | −0.05 (−0.92, 0.81) | 0.90 |
| Visual emphysema severity (%), log-transformed 1,2 | ||||||
| Unadjusted (n = 50) | −0.0007 (−0.005, 0.004) | 0.73 | 0.006 (0.002, 0.009) | 0.001 * | 1.61 (0.36, 2.86) | 0.01 * |
| Model 1 (n = 50) | −0.0005 (−0.005, 0.004) | 0.80 | 0.005 (0.002, 0.008) | 0.003 * | 1.46 (0.29, 2.63) | 0.01 * |
| Model 2 (n = 49) | 0.0009 (−0.004, 0.005) | 0.69 | 0.003 (0.0001, 0.007) | 0.04 * | 0.87 (−0.38, 2.11) | 0.17 |
| Severity scores of pulmonary emphysema subtypes, log-transformed 1,3 | ||||||
| Unadjusted (n = 50) | ||||||
| CLE severity | 0.003 (−0.004, 0.009) | 0.38 | −0.0006 (−0.006, 0.005) | 0.82 | −0.42 (−2.31, 1.48) | 0.67 |
| PLE severity | 0.001 (−0.005, 0.008) | 0.68 | 0.002 (−0.002, 0.007) | 0.33 | 0.96 (−0.84, 2.76) | 0.30 |
| PSE severity | −0.006 (−0.01, 0.002) | 0.13 | 0.008 (0.002, 0.01) | 0.005 * | 2.29 (0.22, 4.37) | 0.03 * |
| Model 1 (n = 50) | ||||||
| CLE severity | 0.003 (−0.004, 0.009) | 0.39 | −0.0001 (−0.005, 0.005) | 0.97 | −0.20 (−2.02, 1.62) | 0.83 |
| PLE severity | 0.001 (−0.005, 0.007) | 0.76 | 0.002 (−0.002, 0.007) | 0.29 | 1.31 (−0.46, 3.08) | 0.15 |
| PSE severity | −0.004 (−0.01, 0.003) | 0.24 | 0.006 (0.0002, 0.01) | 0.04 * | 1.53 (−0.54, 3.60) | 0.15 |
| Model 2 (n = 49) | ||||||
| CLE severity | 0.004 (−0.003, 0.01) | 0.29 | −0.001 (−0.006, 0.004) | 0.69 | −0.56 (−2.42, 1.30) | 0.56 |
| PLE severity | 0.0009 (−0.005, 0.007) | 0.77 | 0.003 (−0.002, 0.007) | 0.28 | 1.33 (−0.44, 3.09) | 0.14 |
| PSE severity | −0.003 (−0.01, 0.005) | 0.50 | 0.004 (−0.002, 0.01) | 0.17 | 0.69 (−1.45, 2.83) | 0.53 |
1 Continuous exposure variables (i.e., %emphysema, pulmonary emphysema subtype severity scores) were log-transformed to achieve approximately normal distributions of residuals. 2 Calculated as the sum of the severity scores for centrilobular, panlobular, and paraseptal emphysema. 3 Pulmonary emphysema subtypes are adjusted for each other. * p-value < 0.05. CLE, centrilobular emphysema; PLE, panlobular emphysema; PSE, paraseptal emphysema. Mixed models with a random intercept, variance component (VC) structure, and Kenward-Roger’s. approximation of the degrees of freedom were used. Participants were weighted on the inverse ratio of probability of selection. Pulmonary emphysema subtypes were qualitatively assessed at the baseline MESA COPD exam and scored from 0–100. Two participants were excluded due to non-physiological results. Unadjusted: (weighted). Model 1: adjusted for age, sex, race/ethnicity, and cigarette smoking status (weighted). Model 2: Model 1 + %-predicted FEV1 (weighted).