1. CPAP does not reduce high-sensitivity c-reactive protein in patients with coronary artery disease and obstructive sleep apnea
- Author
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Akshay K. Mahadevia, Gautum Reddy, Nicolas W. Shammas, Dawn McKinney, Jon H. Lemke, Eric J. Dippel, Matthew J Kapalis, Harb Harb, and Moutasim H. Al-Shaer
- Subjects
medicine.medical_specialty ,Ejection fraction ,medicine.diagnostic_test ,biology ,business.industry ,medicine.medical_treatment ,C-reactive protein ,medicine.disease ,respiratory tract diseases ,Surgery ,Coronary artery disease ,Obstructive sleep apnea ,Blood pressure ,Internal medicine ,biology.protein ,Cardiology ,Medicine ,Continuous positive airway pressure ,Cardiology and Cardiovascular Medicine ,business ,Lipid profile ,Body mass index - Abstract
Obstructive sleep apnea (OSA) is associated with an increase in high-sensitivity C-reactive protein (hs-CRP). Studies suggested that the degree of severity of OSA in obese patients with no known coronary artery disease correlates with higher levels of hs-CRP and that continuous positive airway pressure (CPAP) could reduce this inflammation marker. In this study we tested the hypothesis that CPAP therapy could also reduce hs-CRP in cardiac patients with multiple comorbidities and known OSA. Sixty-two consecutive patients were included in this study. All patients were referred for a sleep test because of clinical suspicion of OSA. Clinical variables, body mass index (BMI), hs-CRP, and lipid profile were obtained at the time of their referral and at 126.2 ± 33.7 days followup. Thirty-four patients (group A) underwent CPAP therapy and 28 patients did not (group B). The linear regression of hs-CRP level on the severity of the apnea–hypopnea index (AHI) was significant (p = 0.05), but this significance is lost when ln(hs-CRP) was used (p = 0.263). Through analysis of covariance, ln(hs-CRP) was predicted by BMI (p = 0.000) (R-Sq = 46.2%). In group A, and despite a significant drop in the AHI with CPAP [median difference = −29.7 (−41.8, −22.2)], there were no significant differences in patients’ BMI, lipid profile, or hs-CRP [median difference = −0.15 (−0.83, 0.64)] (p = 0.53) on followup. When both groups A and B were compared, they had matched BMI, lipids, ejection fraction, blood pressure, age, creatinine, awake O2 saturations, alcohol consumption, coronary artery disease, and baseline and followup hs-CRP despite significant differences in baseline AHI (37.65 vs 14.30, respectively, p = 0.000). We conclude that the degree of OSA or CPAP treatment does not independently predict levels of ln(hs-CRP) in cardiac outpatients when other clinical variables, BMI, and lipids are adjusted for. BMI remains the strongest independent predictor of hs-CRP in this patient population.
- Published
- 2011