LOS ANGELES – While a large number of older adults take prescription and nonprescription medications to help them sleep, the effect of these medications on dementia risk is unclear, with most researchers advocating a cautious and conservative approach to prescribing.
Nastasic/iStockphoto.com
Research is increasingly revealing a bidirectional relationship between sleep and dementia. Poor sleep – especially from insomnia, sleep deprivation, or obstructive sleep apnea – is known to increase dementia risk. Dementias, meanwhile, are associated with serious circadian rhythm disturbances, leading to nighttime sleep loss and increasing the likelihood of institutionalization.
At the Alzheimer’s Association International Conference, researchers presented findings assessing the links between sleep medication use and dementia and also what agents or approaches might safely improve sleep in people with sleep disorders who are at risk for dementia or who have been diagnosed with dementia.
Sex- and race-based differences in risk
Yue Leng, PhD, of the University of California, San Francisco, reported a link between frequent sleep medication use and later dementia – but only in white adults. Dr. Leng presented findings from the National Institutes of Health–funded Health, Aging, and Body Composition Study, which recruited 3,068 subjects aged 70-79 and followed them for 15 years. At baseline, 2.7% of African Americans and 7.7% of whites in the study reported taking sleep medications “often” or “almost always.”
Dr. Leng and her colleagues found that white subjects who reported taking sleep aids five or more times a month at baseline had a nearly 80% higher risk of developing dementia during the course of the study (hazard ratio, 1.79; 95% confidence interval, 1.21-2.66), compared with people who reported never taking sleep aids or taking them less frequently.
The researchers saw no between-sex differences for this finding, and adjusted for a variety of genetic and lifestyle confounders. Importantly, no significant increase in dementia risk was seen for black subjects, who made up more than one-third of the cohort.
Dr. Leng told the conference that the researchers could not explain why black participants did not see similarly increased dementia risk. Also, she noted, researchers did not have information on the specific sleep medications people used: benzodiazepines, antihistamines, antidepressants, or other types of drugs. Nonetheless, she told the conference, the findings ratified the cautious approach many dementia experts are already stressing.
“Do we really need to prescribe so many sleep meds to older adults who are already at risk for cognitive impairment?” Dr. Leng said, adding: “I am a big advocate of behavioral sleep interventions.” People with clinical sleep problems “should be referred to sleep centers” for a fuller assessment before medication is prescribed, she said.
Findings from another cohort study, meanwhile, suggest that there could be sex-related differences in how sleep aids affect dementia risk. Investigators at Utah State University in Logan used data from some 3,656 older adults in the Cache County Study on Memory and Aging, an NIH-backed cohort study of white adults in Utah without dementia at baseline who were followed for 12 years.
The investigators, led by doctoral student Elizabeth Vernon, found that men reporting use of sleep medication saw more than threefold higher risk of developing Alzheimer’s disease than did men who did not use sleep aids (HR, 3.604; P = .0001).
Women who did not report having sleep disturbance but used sleep-inducing medications were at nearly fourfold greater risk for developing Alzheimer’s disease (HR, 3.916; P = .0001). Women who self-reported sleep disturbances at baseline, meanwhile, saw a reduction in Alzheimer’s risk of about one-third associated with the use of sleep medications.
Ms. Vernon told the conference that, despite the finding of risk reduction for this particular group of women, caution in prescribing sleep aids was warranted.