JAMA:老年女性睡眠质量不佳易患痴呆

Context Sleep-disordered breathing (characterized by recurrent arousals from sleep and intermittent hypoxemia) is common among olderadults. Cross-sectional studies have linked sleep-disordered breathing to poor cognition; however, it remains unclear whethersleep-disordered breathing precedes cognitive impairment in older adults.Objectives To determine the prospective relationship between sleep-disordered breathing and cognitive impairment and to investigatepotential mechanisms of this association.Design, Setting, and Participants Prospective sleep and cognition study of 298 women without dementia (mean [SD] age: 82.3 [3.2] years) who had overnight polysomnographymeasured between January 2002 and April 2004 in a substudy of the Study of Osteoporotic Fractures. Sleep-disordered breathingwas defined as an apnea-hypopnea index of 15 or more events per hour of sleep. Multivariate logistic regression was used todetermine the independent association of sleep-disordered breathing with risk of mild cognitive impairment or dementia, adjustingfor age, race, body mass index, education level, smoking status, presence of diabetes, presence of hypertension, medicationuse (antidepressants, benzodiazepines, or nonbenzodiazepine anxiolytics), and baseline cognitive scores. Measures of hypoxia,sleep fragmentation, and sleep duration were investigated as underlying mechanisms for this relationship.Main Outcome Measures Adjudicated cognitive status (normal, dementia, or mild cognitive impairment) based on data collected between November 2006and September 2008.Results Compared with the 193 women without sleep-disordered breathing, the 105 women (35.2%) with sleep-disordered breathing weremore likely to develop mild cognitive impairment or dementia (31.1% [n = 60] vs 44.8% [n = 47]; adjusted odds ratio [AOR],1.85; 95% confidence interval [CI], 1.11-3.08). Elevated oxygen desaturation index (≥15 events/hour) and high percentage ofsleep time (>7%) in apnea or hypopnea (both measures of disordered breathing) were associated with risk of developing mildcognitive impairment or dementia (AOR, 1.71 [95% CI, 1.04-2.83] and AOR, 2.04 [95% CI, 1.10-3.78], respectively). Measuresof sleep fragmentation (arousal index and wake after sleep onset) or sleep duration (total sleep time) were not associatedwith risk of cognitive impairment.Conclusion Among older women, those with sleep-disordered breathing compared with those without sleep-disordered breathing had an increasedrisk of developing cognitive impairment.