Table 3.
Associations of sleep-related hypoxemia (nadir saturation) with subclinical interstitial lung disease on computed tomography in Multi-Ethnic Study of Atherosclerosis
| Mean Percent HAA Increment Compared with a Saturation ≥ 90% (95% CI) |
Odds Ratio for ILA Compared with a Saturation ≥ 90% (95% CI) |
|||||||
|---|---|---|---|---|---|---|---|---|
| <80% | 80–89% | ≥90% | P Trend | <80% | 80–89% | ≥90% | P Trend | |
| Precision adjusted | 6.1 (2.6 to 9.8) | 3.8 (0.9 to 6.8) | 0 (Ref) | 0.003 | 1.64 (1.23 to 2.17) | 1.21 (0.92 to 1.61) | 1 (Ref) | <0.001 |
| Adjusted | 4.6 (1.3 to 8.0) | 2.4 (–0.4 to 5.2) | 0 | 0.01 | 1.35 (0.86 to 2.11) | 1.09 (0.76 to 1.58) | 1 | 0.08 |
| Adjusted with BMI interaction term | ||||||||
| <25 kg/m2 | 6.9 (–0.1 to 14.3) | 3.1 (–1.1 to 7.5) | 0 | 0.049 | 0.71 (0.14 to 3.60) | 2.02 (0.93 to 4.41) | 1 | 0.59 |
| 25–30 kg/m2 | −0.5 (–5.7 to 4.9) | 2.1 (–2.4 to 6.8) | 0 | 0.79 | 0.86 (0.28 to 2.62) | 0.70 (0.28 to 1.76) | 1 | 0.95 |
| >30 kg/m2 | 2.6 (–4.1 to 9.8) | −1.8 (–8.0 to 4.8) | 0 | 0.03 | 1.89 (0.48 to 7.41) | 1.31 (0.27 to 6.30) | 1 | 0.003 |
| Adjusted with smoking interaction term | ||||||||
| Never-smokers | 8.1 (3.3 to 13.2) | 4.4 (0.4 to 8.6) | 0 | 0.002 | 0.97 (0.50 to 1.89) | 0.98 (0.40 to 2.37) | 1 | 0.93 |
| Ever-smokers | 9.0 (4.2 to 14.1) | 5.1 (1.0 to 9.4) | 0 | 0.001 | 2.29 (1.08 to 4.82) | 1.51 (0.72 to 3.16) | 1 | 0.008 |
Definition of abbreviations: BMI = body mass index; CI = confidence interval; HAA = high-attenuation area; ILA = interstitial lung abnormality; Ref = reference category; SpO2 = oxygen saturation as measured by pulse oximetry.
The precision-adjusted HAA model includes milliampere (mA) dose, imaged lung volume, and study site for HAA. Note that mA dose is BMI based, and that this model adjusts for BMI greater than 30 and for BMI less than 20. The precision-adjusted ILA model includes only cluster-robust variance estimation to account for study site. The adjusted HAA model includes adjustment for age, sex, race, educational attainment, height, smoking status, cigarette pack-years, glomerular filtration rate, study site, percent emphysema, milliampere radiation dose, and total volume of imaged lung. The adjusted ILA model includes adjustment for age, sex, race, smoking status, cigarette pack-years, and cluster-robust variance estimation for study site.
For the HAA model, P = 0.02 for the interaction between nadir SpO2 and BMI, and P = 0.96 for the interaction between nadir SpO2 and smoking. For the ILA model, P = 0.56 for the interaction between nadir SpO2 and BMI, and P = 0.42 for the interaction between nadir SpO2 and smoking.