Effects of Continuous Positive Airway Pressure on Lipidaemia and High-sensitivity C-reactive Protein Levels in Non-obese patients with Coronary Artery Disease and Obstructive Sleep Apnoea

Huang, Z., Liu, Z., Zhao, Q., Luo, Q., Tang, Y.

Heart, Lung and Circulation, 2016 Jan 4 (Epub ahead of print)

PMID: 26804247


The effect of obesity and medication on the relationship between obstructive sleep apnoea (OSA) and lipidaemia and systemic inflammation is not fully understood for various reasons. The aim of the present study is to determine the effects of 12 months of therapy with continuous positive airway pressure (CPAP) on lipid profiles and high-sensitivity C-reactive protein (hs-CRP) in non-obese patients with coronary artery disease (CAD) and OSA.

It is a prospective, randomized, controlled clinical trial of parallel groups of OSA patients with CAD, which was defined as at least on selective coronary angiogram, documented history of myocardial infarction or coronary artery bypass grafting. They consecutively recruited 78 non-obese subjects with newly diagnosed CAD and moderate-to-severe OSA who were taking lipid-lowering medication. The selection of patients was from January 2010 to December 2012 in a single-center. Body mass index ≥25 kg/m2 was exclusion criteria. The current study was enroll in Asia population. The majority of population was male. Patients were randomized to CPAP treatment or the control group. The patients' lipids and the hs-CRP level were measured at baseline and at follow-up. 70 patients completed the study. The mean duration of CPAP treatment was 4.2 ±1.1 h/night. There was no significant difference in the lipids or hs-CRP levels at 12 months. The apnoae-hypopnoea index and Epworth Sleepiness Scale were significantly lower in the CPAP treatment group than in the control group.

CPAP treatment in non-obese patients with CAD and OSA who are taking standardized lipid-lowering treatment does not significantly decrease the lipid or hs-CRP levels. In addition, there are no relationships found between the severity of OSA and the lipid profiles. However, the status of OSA and daytime sleepiness improved significantly in the CPAP group.

Clinical implications: Coronary artery disease patients with OSA and obesity who persist with behavioral weight loss treatment may exhibit reduced circulating markers of lipids and hs-CRP, consequently decreasing the risks. Nonetheless, considering the improvements of daytime sleepiness and its potential benefits, CPAP is recommended for CAD patients with moderate to severe OSA. Obesity is the principal determinant of dyslipidemia, underlying the cause of atherosclerosis, irrespective of the presence of OSA or its severity.

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