Association Between Severity of Obstructive Sleep Apnea and High-sensitivity C-reactive Protein in Patients with Hypertrophic Obstructive Cardiomyopathy

Background: Obstructive sleep apnea (OSA) is highly prevalent in patients with hypertrophic obstructive cardiomyopathy (HOCM). Inflammatory responses are increased in patients with OSA, meanwhile, inflammation is also associated with adverse outcomes in HOCM.

Hypothesis: To investigate the association between severity of OSA and high-sensitivity C-reactive protein (hs-CRP) in patients with HOCM.

Methods: Three hundred and ninteen patients with HOCM who underwent sleep evaluations at Fuwai Hospital were retrospectively included between February 2010 and December 2018. Data from baseline clinical characteristics and polysomnography studies were collected.

Results: OSA was present in 168 (52.7%). Patients with OSA were older, more likely to be male, had a higher body mass index and more clinical comorbidities. Patients with OSA had enlarged left ventricular diameter and similar left ventricular outflow tract obstruction compared with those without. In multivariate logistic analysis, apnea-hypopnea index (OR, 1.024; 95% CI, 1.005-1.044; P = .014), oxygen desaturation index (OR, 1.025; 95% CI, 1.004-1.046; P = .018) and lowest oxygen saturation (OR, 0.951; 95% CI, 0.915-0.989; P = .011) were independently associated with high risk hs-CRP (>3 mg/L) after adjusting for confounders. In addition, decreasing lowest oxygen saturation (β = -.159, P = .004) was also independently correlated with increasing hs-CRP concentrations in multivariate linear analysis after adjusting for confounders.

Conclusions: Severity of OSA was independently associated with elevated hs-CRP levels in patients with HOCM. Further studies are needed to evaluate the effects of treating OSA on hs-CRP as well as clinical outcomes in these patients.