Sleeping poorly may increase a person's risk of being placed in a nursing home later in life, a new study suggests.

In the study, older women whose sleep was the most fragmented had about three times the odds of being placed in a nursing home five years later, compared with women whose sleep was the least fragmented.

Previous studies have linked disturbed sleep with disabilities in older adults, and impairment in activities of daily living and mobility, the researchers said.

The study found an association, and not a cause-effect link. But if the findings are confirmed, it's possible that treating sleep disturbances in older adults could improve their ability to function and reduce their risk of institutionalization, the researchers said.

Adam Spira, of the Johns Hopkins Bloomberg School of Public Health, and colleagues analyzed information from more than 1,600 women whose average age was 83, who did not live in a nursing home at the study's start.

Participants wore wrist devices called actigraphs, which measure movements and can be used to tell if someone is asleep or awake, for at least three days. On an average night, participants spent close to seven hours in bed. After they had initially fallen asleep, they spent a total of about one hour of the night awake.

Five years later, researchers tracked the participants to see if they had moved to a nursing home or an assisted-living facility.

People who spent the most time awake during the night (about two hours) were more likely to be living in a nursing home five years later than those who spent the least time awake (about a half hour).

There are several ways to explain the link. It's possible that an underlying disease, such as Alzheimer's disease, could cause both the fragmented sleep and the need to live in a nursing home, the researchers said. It's also possible those who care for an older adult experience increased stress when the older adult does not sleep, which results in placement of the older adult in a nursing home.

Finally, poor sleep quality may increase inflammation in the body, which has been linked with lower levels of physical function, the researchers said.

More work is needed to understand exactly how sleep disturbance is related to an increased risk of institutionalization in older adults, the researchers said.

The study is published in the July issue of theJournal of the American Geriatrics Society.

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