Too much or too little sleep among people with type 2 diabetes (T2D) can be deadly, according to a new study published by the European Association for the Study of Diabetes. The researchers found that for T2D patients, extreme sleep duration drastically increases the risk of death.
While previous studies have established a link between extreme sleep duration and increased mortality, the new study was designed to investigate the potential role of diabetes in this relationship.
Led by Dr. Chuanhua Yu and Dr. Xiong Chen, the research was focused on data from the U.S. National Health Interview Survey, which followed up with 273,029 adults for more than a decade. Among the survey participants, 24,212 had type 2 diabetes.
As expected, death rates were higher in people with T2D than those without, regardless of sleep duration.
The mortality rate for T2D patients with the “ideal” seven hours of sleep was 138 per 10,000 person years, compared to 215 for less than five hours sleep and 364 for those with 10 hours of sleep or more.
The reference group used for the analysis was participants without diabetes who slept seven hours per night. Compared to this group, people with T2D who slept for seven hours had a 42 percent increased risk of death. This risk was elevated to 63 percent among sleep-deprived T2D patients, and was more than doubled for T2D patients who slept 10 or more hours.
The researchers also identified links between sleep duration and cause-specific mortality. For example, diabetics with excessive sleep patterns had a 59 percent greater risk of death from cancer. This group was also found to have a 74 percent increased risk of fatal cardiovascular disease, three times higher risk of fatal stroke, and 2.6 times greater risk of death from Alzheimer’s.
The mortality risk of extreme sleep duration was generally higher in individuals who had been diagnosed with diabetes more than ten years earlier. The link was also stronger in those who had been diagnosed with T2D before the age of 45.
The study authors explained that sleep deprivation in people with T2DM is likely to increase complications and affect the control and management of blood glucose, which drive excess mortality risk. They also pointed out that longer sleep duration is often a reflection of poorer health status and complications that require more rest.
Another possible explanation of the findings is that longer sleep duration has been associated with detrimental chronic inflammatory responses.
“For people with T2DM, as per the general population, 6 to 8 hours of sleep is recommended on account of reducing mortality risk. Sleep interventions as an addition to standard diabetes treatment may warrant further attention,” wrote the researchers.
“This study provides preliminary evidence that the associations between sleep duration and mortality are different between people with and without diabetes. Patients with diabetes sleeping for less than or in excess of 7 hours had an increased risk of all-cause and cause-specific mortality, while too much or too little sleep also increased absolute death rates in people without diabetes, but to a lesser extent.”
“The association was more prominent in those with younger age at disease onset. These patients may require greater medical attention that targets sleep and lifestyle to reduce the risks of adverse health outcomes.”
The study is published in the journal Diabetologia.