Effect of cardiac rehabilitation on inflammatory markers in patients with high risk for obstructive sleep apnea: a pilot study.

Our primary objective in this study was to determine the differences in inflammatory profile between patients with high risk for obstructive sleep apnea (OSA) versus low risk in a patient population undergoing cardiac rehabilitation and to evaluate the effect of 4 weeks of rehabilitation on cytokine levels in the 2 groups. A total of 20 consecutive patients were screened using the Berlin questionnaire to determine high and low risk of OSA. Of the 20 total consecutive patients, 3 patients did not consent to participate and 1 did not get cytokine analysis. Of the remaining 16 patients (8 men and 8 women), 8 (50%) patients were found to have high risk for OSA as predicted by the Berlin questionnaire. Men predominated the high-risk group (75%). There was a trend of increased cytokine load in the high-risk group; however, it did not reach statistical significance except for monocyte chemoattractant protein-1 (P value=0.02). A significant reduction was noted in cytokine levels after 4 weeks of rehabilitation in the group with OSA, which was statistically significant (P value<0.5). The high-risk group patients had elevated cytokine levels, especially monocyte chemoattractant protein-1. Further, a significant reduction in cytokine levels was noted in the high-risk group after 4 weeks of rehabilitation.