0456 Impact of Hypertension and Sleep-disordered Breathing on Cognitive Decline in Older Adults

Abstract Introduction Hypertension is a major risk factor for cardiovascular diseases. Sleep disruption, circadian dysfunction, sleep-disordered breathing (SDB), and cognitive decline are increased with aging. Repeated episodes of end-apneic arousal or hypoxia and consequent sleep fragmentation are associated with increased nocturnal blood pressure, possibly leading to sustained hypertension and atherosclerosis. The relationship between blood pressure levels and cognitive function differs across the lifespan in observational studies. However, the roles of hypertension and SDB on the pathogenesis of age-related cognitive decline remain unclear. We investigated the effect of hypertension and SDB on cognitive decline in older adults. Methods The participants were 50 consecutive volunteers aged 60 years or older (mean age 69.2 ± 4.7 years) without impairment in daily living activities. Sleep apnea screenings were conducted using a portable monitor. We evaluated the respiratory event index (REI) as the number of apnea and hypopnea events per hour during the recording time, with the minimum oxygen saturation. Sleep complaints were assessed using the Pittsburg sleep quality Index (PSQI). Excessive daytime sleepiness was evaluated by the Epworth sleepiness scale (ESS). Cognitive performance was assessed using the Wisconsin card sorting test (WCST), continuous performance test-identical pairs (CPT-IP), and N-back task. Hypertension and diabetes mellitus were evaluated via questionnaire. We measured systolic and diastolic blood pressure using pulse wave test. Results The percentage of correct answers on the 1-back tasks was significantly lower in the hypertension group than the non-hypertension group. The WCST category achievement was significantly lower in the participants with minimum oxygen saturation 90% than those with minimum oxygen saturation ≥ 90%. Minimum oxygen saturation was correlated with category achievement on the WCST. Multiple regression analysis including age, REI, minimum oxygen saturation, ESS, hypertension, and diabetes mellitus revealed that hypertension was the most significant factor for percentage of correct answers on the 1-back tasks. There were no significant correlations between the REI or ESS and the parameters of WCST or N-back tasks. Conclusion Hypertension and SDB may negatively affect cognitive function in older adults. Our findings suggest that the appropriate management of hypertension and SDB is important in mid- and late-life. Support (if any)