MINNEAPOLIS – Midlife insomnia increases the likelihood of retiring because of poor health or disability, a longitudinal cohort study among 1,590 Wisconsin state employees showed.
Previous research has established that insomniacs retire earlier than peers without this sleep disorder, according to lead researcher Lauren Hale, Ph.D., of the public health program, Stony Brook (N.Y.) University. But the reasons for retiring are unclear.
She and her colleagues analyzed data from the REST (Retirement and Sleep Trajectories Study) cohort, a mixed group of blue- and white-collar Wisconsin state employees who were followed from midlife onward and completed questionnaires probing their reasons for retiring.
Dr. Lauren Hale
Overall, 41% of the participants had insomnia at approximately 50 years of age based on their report of often or almost always experiencing at least one of four symptoms of the disorder, Dr. Hale reported at the annual meeting of the Associated Professional Sleep Societies.
As of 2013, two-thirds of the entire cohort had retired, most commonly citing reasons of wanting to do other things, being financially secure, and wanting more time to spend with family and friends.
But after the data were adjusted for covariates, insomnia was most strongly and significantly associated with retiring because of poor health or disability (P less than .001). And the more insomnia symptoms a participant reported, the higher his or her risk of retiring for this reason; those reporting three or four symptoms had approximately twice the risk of peers without insomnia.
Surprisingly, insomnia did not increase the risk of retirement because of being laid off (as might be expected if employees were frequently late to work because of sleep loss) or retirement because of needing to care for a family member (a stressor that might be expected to lead to insomnia), according to Dr. Hale.
"We confirmed our hypothesis that the leading reason that people who have insomnia symptoms in early life are retiring earlier is due to poor health or disability as they are getting older," she commented.
"Now, there is still work to be done; the temporal sequencing is not 100% clear," said Dr. Hale.
Although it appears that the insomnia is preceding poor health, which then triggers early retirement, it is also possible that the poor health comes first and gives rise to insomnia, ultimately leading to the decision to retire, she explained. And there is a third possibility. "There are of course many unmeasured health variables that we didn’t include in the models that might be preceding the insomnia at age 50 and then leading to early retirement. And of course there are a range of unmeasured factors – social, psychosocial, cultural – that could be leading to both concurrent insomnia and poor health, that lead to early retirement," she explained. "So we hope to probe into that in the future."
In an interview, session chair Dr. Nalaka S. Gooneratne of the department of medicine atthe Hospital of the University of Pennsylvania and the Presbyterian Medical Center of Philadelphia, said: "I think these findings have very important public health ramifications. It’s very important for the field of sleep to not just look at the effects of sleep on immediate disease outcomes, but also on public health factors such as retirement and quality of life for retirees, and maximizing functional status and independence for older adults.
"Some of this data is really quite intriguing, suggesting there are hitherto unappreciated links between sleep and the decisions people make later on in their life about how they want to manage their retirement and finances," he added. "I think it’s very important to fund and explore research on the links between aging and sleep, especially with the growing numbers of older adults in the population."
Dr. Hale disclosed no relevant conflicts of interest.