May 1 (HealthDay News) -- Older adults with sleep problems, pain, diabetes and respiratory problems are more likely to take naps during the day, a U.S. study finds.

Researchers from Vanderbilt University Medical Center in Nashville, Tenn., looked at 235 people, average age 80.1 years, who were monitored for an average of 6.8 nights. The team used wrist actigraphy to gather data on the participants' sleep patterns and circadian rhythms. The volunteers also kept sleep diaries.

The results showed that naps of at least five minutes were recorded in sleep diaries by 75.7 percent of the participants. Napping was most likely to occur in those with higher levels of nighttime sleep fragmentation, respiratory symptoms, diabetes and pain.

Self-reported diabetes was associated with a 43 percent longer nap duration, while self-reported pain was associated with a 27.5 percent shorter nap duration. Each hour of previous night's sleep time was associated with a 4.1 percent longer sleep time the next night (nap night), and each hour of napping (the next day) was associated with 10.2 percent less sleep on the night of the nap.

"Our study is important both clinically and for future research. It points out the need for health care providers to discuss nighttime sleep and daytime napping with older individuals," study author Suzanne E. Goldman said in a prepared statement.

The study "also points out the need to identify the causes of disturbed nighttime sleep in order to determine appropriate treatment. Our study suggests that older adults nap because of health problems and disrupted sleep at night. Thus the napping may reflect needed sleep," Goldman said.

The study was published in the May 1 issue of Sleep.

Lack of sleep can lead to a number of problems in older adults, including depressed mood, attention and memory problems, excessive daytime sleepiness, more nighttime falls, and increased use of sleep medications.

Research has also linked lack of sleep with increased risk of serious health problems such as obesity, cardiovascular disease and diabetes.

SOURCE: American Academy of Sleep Medicine, news release, May 1, 2008