Inflammation in patients with obstructive sleep apnea and coronary artery disease

Abstract

Background and objective

Obstructive sleep apnea (OSA) and coronary artery disease (CAD) are known to be associated with activation of inflammatory pathways. Treatment of OSA is hypothesized to lead to a reduction in inflammation. This study investigated the association between OSA and inflammation in CAD patients, and determined the effect of one night of continuous positive airway pressure (CPAP) therapy.

Materials and methods

Patients with stable CAD and moderate–severe OSA underwent overnight polysomnography (PSG) one night, and again during CPAP the following night. Cardiac stress and inflammation markers were determined in the morning after each PSG.

Results

Included were 23 patients with OSA (74% male; age 63 ± 10 years; ejection fraction 50 ± 8%). During CPAP, the most remarkable decreases from baseline were observed in the apnea–hypopnea index (AHI; from 35 ± 21 to 11 ± 11/h; p < 0.001), high-sensitivity C‑reactive protein (hs-CRP; 0.396 ± 0.428 to 0.308 ± 0.299 mg/dL; p = 0.006), and creatine kinase-MB (CKMB; 1.818 ± 1.014 to 1.551 ± 0.819 U/L; p = 0.018). After adjusting for age, gender, obesity, and heart failure severity as relevant confounders, there was a significant correlation between baseline AHI and myoglobin (r = 0.650; p = 0.002). Likewise, there were correlations between mean desaturation and CKMB (r = 0.606, p = 0.007), and between time spent with O₂ saturation <90% (T < 90%) and interleukin 6 (r = 0.525, p = 0.013).

Conclusion

Among CAD patients there are clear correlations between surrogate measures of OSA severity, such as T < 90%, mean desaturation, and AHI, and inflammation, even after adjustment for obesity and the severity of heart failure as crucial confounding factors. Effective treatment of OSA with CPAP decreased cardiac stress and inflammation.

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