Table 5.
Associations between measures of sleep-disordered breathing and serum biomarkers
| Mean Percent Biomarker Increment* | 95% CI | P Value | P for Interaction with BMI | |
|---|---|---|---|---|
|
Obstructive AHI | ||||
| MMP-7 | <0.001 | |||
| Overall | 3.4 | 0.8 to 6.0 | 0.01 | |
| BMI < 25 | 16.6 | 9.7 to 24.0 | <0.001 | |
| BMI > 25 | 1.6 | −0.9 to 4.1 | 0.21 | |
| SP-A | 0.03 | |||
| Overall | 4.1 | −0.5 to 8.9 | 0.08 | |
| BMI < 25 | 17.5 | 4.5 to 32.2 | 0.008 | |
| BMI > 25 | 1.7 | −3.0 to 6.6 | 0.48 | |
|
Nadir Saturation | ||||
| MMP-7 | 0.19 | |||
| Overall | 4.2 | −0.4 to 9.0 | 0.07 | |
| BMI < 25 | 15.0 | −0.8 to 33.2 | 0.06 | |
| BMI > 25 | 3.6 | −1.2 to 8.7 | 0.15 | |
| SP-A | 0.15 | |||
| Overall | 9.1 | 0.8 to 18.1 | 0.03 | |
| BMI < 25 | 22.8 | −5.3 to 59.1 | 0.12 | |
| BMI > 25 | 6.4 | −2.2 to 15.7 | 0.15 | |
|
Central Sleep Apnea Index | ||||
| MMP-7 | 0.93 | |||
| Overall | 6.8 | −3.8 to 18.5 | 0.21 | |
| BMI < 25 | 5.4 | −8.1 to 21.0 | 0.45 | |
| BMI > 25 | 6.4 | −9.0 to 24.4 | 0.43 | |
| SP-A | 0.95 | |||
| Overall | −2.7 | −19.4 to 17.5 | 0.77 | |
| BMI < 25 | 0.8 | −21.0 to 28.7 | 0.95 | |
| BMI > 25 | −0.4 | −24.5 to 31.5 | 0.98 | |
Definition of abbreviations: AHI = apnea–hypopnea index; BMI = body mass index; CI = confidence interval; MMP-7 = metalloproteinase-7; SP-A = surfactant protein-A.
All models adjusted for age, sex, race, and smoking status. “Overall’ models include adjustment for BMI.
*
Adjusted mean percent increment in each biomarker per 5-unit absolute increase in obstructive AHI, 5% absolute decrement in nadir saturation, or 1-unit increase in central sleep apnea index.