Relationship between obstructive sleep apnea and coronary microcirculatory function among patients with cardiac syndrome X.
OBJECTIVE
Obstructive sleep apnea (OSA) is an emerging risk factor for cardiovascular disease. Microcirculatory dysfunction has been proposed as a potential mechanism in the pathogenesis of cardiovascular disease in OSA. This study aims to investigate the relationship between OSA and coronary microcirculatory function.


METHODS
One thousand and thirty-eight patients (598 female, mean age 60±9 years) with angiographically normal coronary arteries were divided into three groups with non-OSA of apnea-hypopnea index (AHI) less than 5 (n=403), mild-to-moderate OSA of AHI 5-30 (n=386), and severe OSA of AHI more than 30 (n=249).


RESULTS
The prevalence of OSA was very high in patients with syndrome X (635/1038). Patients with higher AHI values had a lower coronary flow reserve, were more likely to have a higher total cholesterol, low-density lipoprotein cholesterol, and high sensitive C-reactive protein, and were more likely to be obese. Compared with the non-OSA group, the multivariable-adjusted odds ratio of coronary microcirculatory function for an AHI of 5-30 events/h was 1.93, 95% confidence interval 1.66-3.47, P=0.038, and for an AHI of more than 30 events/h was 2.18, 95% confidence interval 1.62-4.23, P=0.024, in model 1; and coronary microcirculatory function for an AHI of 5-30 events/h and more than 30 events/h odds ratio 1.31, 95% confidence interval 1.06-2.88, P=0.043, versus odds ratio 2.08, 95% confidence interval 1.03-2.16, P=0.036, in model 2.


CONCLUSIONS
As compared with having no sleep apnea, categories with higher AHI were associated with increased odds of lower coronary flow reserve. The data suggested a close relationship between OSA and coronary microcirculatory function in atherosclerosis.
aDepartment of Cardiology, The First Affiliated Hospital bDepartment of Electrocardiology, The Second Affiliated Hospital, Zhengzhou University, Zhengzhou, China.
Na
N
Wang
Shuai-Bing
SB
Li
Luo-Sha
LS
Zhao
Hai-Yu
HY
Li
Zhong-Jian
ZJ
Li
Qiang-Wei
QW
Shi
Yan-Feng
YF
Li
Qing
Q
Zhi
D000368:Aged; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000032:analysis; D016009:Chi-Square Distribution; D002681:China; D008078:Cholesterol, LDL / Q000097:blood; D003326:Coronary Circulation; D003331:Coronary Vessels / Q000503:physiopathology*; D005260:Female; D006801:Humans; D018836:Inflammation Mediators / Q000097:blood; D016015:Logistic Models; D008297:Male; D008833:Microcirculation; D017566:Microvascular Angina / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology*; D055806:Microvessels / Q000503:physiopathology*; D008875:Middle Aged; D015999:Multivariate Analysis; D009765:Obesity / Q000453:epidemiology; D016017:Odds Ratio; D015995:Prevalence; D011446:Prospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D020181:Sleep Apnea, Obstructive / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology*
D015415:Biomarkers; D008078:Cholesterol, LDL; D018836:Inflammation Mediators; D002097:C-Reactive Protein