An unhealthy “trajectory” in the amount of sleep you get each night, over time, may reduce your lifespan, a new study led by researchers at Vanderbilt University Medical Center suggests.
For more than 12 years, the researchers tracked the health of nearly 47,000 adults who recorded how long they slept at two time points, five years apart.
Long-term trajectories of irregular sleep durations outside the optimal range (more or less than the healthy duration of seven to nine hours of sleep per night, maintained over time) increased the risk of death from all causes by as much as 29%, the researchers found.
The study, reported Feb. 27 in the journal JAMA Network Open, included participants in the federally funded Southern Community Cohort Study, which follows the health of predominantly Black and low-income people recruited through community health centers in 12 southeastern states.
“This study makes a significant contribution by studying sleep duration trajectories and mortality in a racially and economically diverse cohort of older adults, who are often underrepresented populations in sleep research,” said the paper’s senior author, Kelsie Full, PhD, MPH, a behavioral epidemiologist and assistant professor of Medicine at VUMC.
The link between sleep trajectories and death appeared to be stronger among white participants and among those with annual household incomes of $15,000 or greater.
However, “we found that suboptimal sleep trajectories were associated with mortality in both racial groups and across household income levels, emphasizing the significance of addressing nonmedical factors that contribute to health,” Full said.
In previous studies, Full and her colleagues have reported that chronically disrupted sleep and highly variable sleep durations may increase the risk for atherosclerosis, and that persistently unhealthy sleep, either not enough or too much, is associated with an increased risk of Type 2 diabetes.
The current study highlights the importance of maintaining healthy sleep over time.
“We were surprised to find nearly two-thirds of participants had irregular or suboptimal sleep trajectories,” the researchers concluded. “Maintaining optimal sleep duration may play an important role in reducing mortality risk.”
Co-authors of the paper were Hui Shi, MS, Loren Lipworth, ScD, and Michael Mumma, MS, from VUMC; Lawrence Dauer, PhD, from Memorial Sloan Kettering Cancer Center in New York; and Qian Xiao, PhD, MPH, from the University of Texas Health Science Center at Houston, School of Public Health.
The Southern Community Cohort Study is supported by grant U01CA202979 from the National Cancer Institute of the National Institutes of Health. SCCS data collection was supported in part by NIH grant P30CA068485 to the Vanderbilt-Ingram Cancer Center.
Other support was provided by NIH grant K01AG083223 from the National Institute on Aging and by a grant from the Alzheimer’s Association.
