Effect of CPAP treatment on plasma high sensitivity troponin levels in patients with obstructive sleep apnea

Background: Obstructive sleep apnea (OSA) is associated with an increased prevalence of cardiovascular diseases. New generations of highly sensitive assays for cardiac troponin (hs-cTnT) have been introduced recently, and a number of clinical observations have challenged the notion that troponins are only increased in blood following irreversible necrosis.

Objective: The aims of this study were to compare the levels of hs-cTnT between a group of healthy controls and a group of patients with OSA without co-existent coronary artery disease, and to assess the possible influence of the treatment with Continuous positive airway pressure (CPAP) on these levels.

Methods: The study population included 200 male participants. The case (n = 133) or control (n = 67) status was defined by an apnea-hypopnea index of 10 or greater. The hs-cTnT assay was validated as reported previously, with a limit of detection of 3 ng/L and an upper reference limit (99th percentile) of 14 ng/L.

Results: The proportion of subjects with detectable plasma hs-cTnT was higher in patients with OSA than in controls (61 vs 75%, p = 0.04). In patients, a significant increase in hs-cTnT levels was observed after an effective treatment with CPAP (7.3 ± 3.4 vs 10.1 ± 4.9 ng/L; p < 0.01).

Conclusion: This study shows that the percentage of subjects with detectable hs-cTnT is associated with the presence of OSA. It also evidences that treatment with CPAP is followed by a rise in hs-cTnT concentrations. It is reasonable to suggest that CPAP therapy might induce a potential degree of cardiac stress, resulting in deleterious consequences for the heart.