A risk biomarker for obstructive sleep apnea in patients with coronary artery disease: monocyte to high-density lipoprotein ratio.

PURPOSE The monocyte to high-density lipoprotein ratio (MHR) has been postulated to be a novel indicator associated with adverse cardiovascular outcomes in patients with coronary artery disease (CAD). These patients often have obstructive sleep apnea (OSA) and whether or not MHR may provide prognostic value for this comorbidity remains unclear. Therefore, we sought to explore the clinical value of MHR in evaluating OSA in patients with CAD. METHODS Consecutive patients with CAD were prospectively recruited and were assigned into four groups based on the quartiles of MHR. Portable monitoring for detecting nocturnal respiratory events was utilized to provide the diagnosis of OSA. Patients were defined as having OSA when respiratory event index ≥ 15 events/h. Univariate and multivariate regression analyses were used to explore the independent association between the levels of MHR and OSA. RESULTS A total of 1243 patients with CAD was included with a prevalence of OSA reaching 40% (n = 497). Patients with higher levels of MHR experienced increasing severity of OSA. In univariate analysis, MHR was a risk factor for OSA (odds ratio [OR] 1.90, 95% confidence interval [CI] 1.33-2.71, p < 0.001). Multivariate analysis showed that MHR was independently associated with the presence of OSA (OR 1.63, 95% CI 1.06-2.52, p = 0.027) after adjusting for possible confounding factors. CONCLUSIONS Elevated levels of MHR were independently associated with a higher likelihood of OSA in patients with CAD. MHR could be a screening tool and a risk biomarker of OSA in such patients.