RISK OF MAJOR ADVERSE CARDIAC EVENTS IN HYPERTENSIVE PATIENTS WITH OBSTRUCTIVE SLEEP APNEA AND METABOLIC SYNDROME: RESULTS OF A LONGITUDINAL COHORT STUDY

Objective: Obstructive sleep apnea (OSA) and metabolic syndrome (MS) may act synergistically and possibly accelerate the initiation and progression of cardiovascular events disease. We examined the joint effect of OSA and MS on the risk of major adverse cardiovascular events (MACE) in hypertensives in a Longitudinal cohort study. Design and method: We conducted a retrospective cohort study enrolling 3134 participants, no history of myocardial infarction (MI), coronary revascularization, unstable angina, and hospitalization for heart failure at baseline, from the Urumqi Research on Sleep Apnea and Hypertension study. An apnoea-hypopnoea index (AHI) of greater than or equal to 5 events per hour recorded by PSG was defined as the diagnostic criterion for OSA. MS was defined using the updated National Cholesterol Education Program Adult Treatment Panel III criteria (ATP III). The outcome was the composite of MACE, which included cardiac death, MI, coronary revascularization, unstable angina and hospitalization for heart failure. We divided participants into four groups for the primary exposure according to the presence/absence of OSA or MS. The Kaplan-Meier method helped to calculate the cumulative incidence of MACE in different groups. Cox proportional hazards regression models were used to evaluate the association of OSA and/or MS with the risk of MACE. Results: During a median follow-up period of 7.06 years (interquartile range: 6.18-8.08 years), 190 incident MACE were identified. Overall, after adjusting for confounding variables, participants with OSA and MS were associated with a 2.51-fold and 1.60-fold increased risk of MACE with corresponding HRs (95% CI) of 2.51 (1.01, 6.21) and 1.60 (1.10, 2.31), compared with participants without OSA and MS, and participants with OSA or MS, respectively. Similar results were obtained in various subgroup and sensitivity analyses. The combination of OSA and MS was associated with the highest risk of MACE among participants who in younger age, and have shorter duration of hypertension. Sensitivity analyses further validated our primary findings. Conclusions: Combination of OSA and MS in hypertension could significantly increase the risk of MACE, suggesting that recognition and treatment of OSA and MS may decrease the cardiovascular risk in hypertensives.