Consistently bad sleep is linked to a person’s risk of developing type 2 diabetes, a new study shows.
Both too little and too much sleep is tied to diabetes risk, and swinging wildly between the two patterns of poor sleep reflects the most risk, researchers reported recently in the journal Diabetologia.
The findings support “the importance of sleep health in midlife, particularly maintaining regular sleep schedules over time, to reduce the risk of adverse cardiometabolic conditions,†said researcher Kelsie Full, a behavioral epidemiologist and assistant professor of medicine at Vanderbilt University Medical Center in Nashville, Tenn.
For the study, researchers analyzed the long-term sleep patterns of more than 36,000 adults participating in a health study of residents in 12 southeastern states in the United States. About 62% of the participants were Black people.
The team examined the participants’ sleep patterns based on what they reported at the start of the study, as well as during a follow-up that took place an average of five years later. Poor sleep was defined as either fewer than seven hours or more than nine hours a night.
“One of the main strengths of our study was that we focused on long-term sleep pattern rather than one-time measurement,†said lead researcher Qian Xiao, an associate professor of epidemiology, human genetics, and environmental sciences at the UT Health Science Center at Houston School of Public Health.
The strongest association with diabetes was found among people who reported extreme changes in sleep patterns, results show.
People who started sleeping too little and grew to sleep too much had the greatest diabetes risk, 51% higher than people with a consistently normal sleep pattern, results show.
The next highest was people who started off sleeping too much and wound up sleeping too little, with a 45% increased risk of diabetes compared to consistently normal sleepers, researchers found.
“By focusing on longitudinal sleep patterns, we demonstrated the importance of maintaining a healthy sleep pattern over time for metabolic health,†Xiao said in a Vanderbilt news release.
Wildly fluctuating sleep patterns have been linked in other studies to poor control of blood sugar levels, researchers said.
Abnormally long sleep duration also might reflect the presence of diabetes-related fatigue or other risk factors associated with the chronic illness, the team added.
Studies are needed to evaluate whether improving sleep health can improve health, researchers said.
The new results jibe with another study published last week involving 84,000 people enrolled in an ongoing U.K. study.
Those findings, published July 17 in the journal Diabetes Care, showed that people with irregular sleep were 34% more likely to develop type 2 diabetes. Irregular sleep was defined as sleep duration that changed by an average of 60 minutes or more between nights.
More information
The National Institutes of Health has more on sleep problems and type 2 diabetes.
SOURCE: Vanderbilt University, news release, June 27, 2024
