Evaluation of association between obstructive sleep apnea and coronary risk scores predicted by tomographic coronary calcium scoring in asymptomatic patients.

OBJECTIVE: This cross-sectional observational study is designed to evaluate direct effects of obstructive sleep apnea syndrome (OSA) on presence and extent of coronary atherosclerosis by using tomographic coronary calcification scoring on a population asymptomatic for coronary artery disease. METHODS: Ninety-seven consecutive patients (49.17 ± 0.86 years) who were evaluated with sleep study for the suspicion of obstructive sleep apnea syndrome underwent tomographic coronary calcium scoring test. Cardiovascular risk factors, current medications and sleep study recordings of all patients were recorded. Patients were classified into 4 groups according to the apnea-hypopnea index (AHI). Linear and logistic regression analyses were used for assessment of association between variables. RESULTS: Coronary risk scores of patients, assessed by tomographic coronary calcium scoring, were observed to increase linearly from simple snoring group to severe OSA groups (p=0.046). When patients were classified according to their gender, AHI and parameters reflecting severity of OSA-related hypoxia were found to correlate significantly with coronary risk scores of women but not with scores of men. Linear regression analysis revealed age as the only independent associated variable with cardiovascular risk scores assessed by tomographic coronary calcification scoring (Beta coefficient: 0.27, 95% CI 0.007-0.087, p=0.018). Binary logistic regression analysis also revealed age as the only variable which independently predicted the presence of coronary calcification (OR:1.11, 95% CI 1.039-1.188, p=0.002). CONCLUSION: These results suggest that presence of OSA may contribute to coronary artery disease risk of patients in association with its severity; however, association between OSA and subclinical atherosclerosis seems to be primarily dependent on age.

Early myocardial functional alterations in patients with obstructive sleep apnea syndrome.

BACKGROUND: There is limited information regarding myocardial alterations in patients with obstructive sleep apnea syndrome (OSAS) in the absence of pulmonary and cardiac comorbidity. In this study, we aimed to evaluate potential myocardial alterations of these patients and investigate the possible effects of OSAS-related pathological variations on left and right ventricular functions. METHODS: We studied 107 consecutive patients who were referred to our sleep laboratory for clinically suspected OSAS and 30 controls without any history or symptoms of sleep-related disorders. Severity of OSAS was quantified by polysomnography. Patients with apnea-hypopnea index (AHI) < 5 were included in the OSAS (-) group (Group 1, n = 22). Subjects with AHI > or = 5 were considered as OSAS and classified according to their AHI as mild-to-moderate (AHI > or = 5 and AHI < 30) (Group 2, n = 45) and severe (AHI > or = 30) OSAS groups (Group 3, n = 40). Conventional M-mode, 2D, and Doppler mitral inflow parameters, tissue Doppler velocities, myocardial peak systolic strain, and strain rate values of various segments were measured and compared between groups. RESULTS: Patients with OSAS displayed impairment of left ventricular diastolic function compared with controls. There were no significant differences between groups regarding parameters reflecting left ventricular systolic function. Myocardial strain analysis demonstrated significant decrement regarding apical right ventricular longitudinal peak systolic strain and strain rate values between groups in relation to the severity of OSAS. CONCLUSIONS: Patients with OSAS display a regional pattern of right ventricular dysfunction correlated with the severity of disease.