Older women with disordered breathing during sleep were found to be at greater risk of decline in the ability to perform daily activities, such as grocery shopping and meal preparation, according to new research.
The study, led by researchers at the Johns Hopkins Bloomberg School of Public Health and the University of California, San Francisco, was published Nov. 6 in the online edition of the Journal of the American Geriatrics Society.
The findings are notable because sleep-disordered breathing is treatable and given the aging of the population an estimated 3.7 million Americans will turn 65 in 2015, and the Census Bureau projects by 2030, 19% of the U.S. population will be 65 or older. Older adults are as much as four times as likely as those who are middle-aged to have problems with breathing during sleep, according to the release.
Sleep-disordered breathing involves repeated interruptions or decreases in breathing during sleep, which often leads to fragmented sleep and hypoxemia. The severity of sleep-disordered breathing is rated with the apnea-hypopnea index, which reflects the number of breathing interruptions (apneas) and the number of significant decreases in breathing (hypopneas) per hour of sleep.
The study found women with an AHI on the moderate to severe side, with 15 or more breathing disruptions per hour of sleep, had a 2.2 times greater odds of decline in daily activity functions during the evaluation period, which averaged five years between baseline evaluation and follow-up.
Because sleep-disordered breathing can be treated effectively, it is possible that treatment could help prevent decline in important areas of functioning that allow older adults to remain independent, lead author Adam Spira, PhD, an associate professor in the mental health department at Johns Hopkins Bloomberg School of Public Health, said in the release. As is often the case, more research is needed to investigate this possibility.
Because the study was observational, the researchers cant conclusively state that sleep-disordered breathing caused the functional decline, but their findings do point to a strong link.
Past studies involving older men have linked sleep-disordered breathing with frailty and death. The authors believe this is one of the first studies to assess the effect of sleep-disordered breathing on decline in older womens ability to perform basic functions associated with independent living.
The study included 302 women, with an average age of 82.3 years. At the start of the study, participants underwent an in-home sleep evaluation. They also were asked whether they had any difficulty performing daily activities, including heavy housework, shopping and preparing meals, or any challenges with mobility, such as walking several blocks or climbing or descending stairs. Participants self-reported daily activities and mobility were assessed once again in a follow-up evaluation.
The researchers said they believe low blood-oxygen levels caused by sleep-disordered breathing cause the trouble with daily tasks, and not sleep fragmentation, which also is increased by sleep-disordered breathing.
Women who reported no difficulties with daily activities during their baseline evaluation but a moderate-to-high AHI had a somewhat higher risk of reporting deterioration in daily-activity function in the follow-up evaluation, the authors found. No links between sleep-disordered breathing severity and decline in mobility were observed.