Cognitive Function in a Sleep Clinic Cohort of Patients with Obstructive Sleep Apnea

摘要

Rationale: Obstructive sleep apnea (OSA) is associated with an increased risk of mild cognitive impairment (MCI) within the general population. However, MCI risk in sleep-clinic populations of patients with OSA is poorly characterized. Objectives: To determine the prevalence of MCI in a sleep-clinic population of patients with OSA and which patients are at the greatest risk for this complication. Methods: Adults (n= 1,084) referred to three academic sleep centers for suspected OSA who had home sleep apnea testing or in-laboratory polysomnography were recruited. Patients completed sleep and medical history questionnaires, the Montreal Cognitive Assessment Test (MoCA) of global cognition, the Rey Auditory Verbal Learning Test of memory, and the Wechsler Adult Intelligence Scale-Fourth Edition Digit-Symbol Coding (DSC) subtest of information processing speed. Results: A MoCA score 55.3% in patients with moderate and severe OSA. Patients with a MoCA 70% higher odds for MCI compared with patients with no OSA (P = 0.003). Memory and information processing speed was lower than age-matched normal values (P< 0.001), with lower MoCA and DSC scores associated with a higher oxygen desaturation index and nocturnal hypoxemia. Conclusions: Cognitive impairment is highly prevalent in patients referred to sleep clinics for suspected OSA, occurring predominantly in older males with moderate to severe OSA and concurrent vascular comorbidities. Moderate to severe OSA is an independent risk factor for MCI.