Insufficient, Excessive Sleep Linked With Increased Risk of Mortality in Patients With Diabetes

Patients with type 2 diabetes (T2D) who sleep too much (≥ 10 hours [h]) or too little (≤ 5 h) had a higher mortality rate, while those in whom diabetes was diagnosed at a younger age who reported longer sleep duration were also associated with greater risks of all-cause and cardiovascular (CVD) mortality, according to study findings published today in Diabetologia.

As the researchers highlight, those with diabetes are at an increased risk of condition-specific morbidity and mortality. Moreover, CVD serves as one of the most frequent diabetes-related causes of death, with sleep duration shown to be a prominent factor in managing this risk in the general population.

The significance of sleep duration has been indicated in prior studies to increase mortality risk among the general population. However, this has not yet been studied among patients with diabetes.

Researchers sought to investigate how the effects of sleep duration interacted with the presence of T2D in all-cause and cause-specific mortality. The study recruited 273,029 adults (T2D, n = 24,212; no diabetes, n = 248,817) who participated in the National Health Interview Survey from 2004 to 2013 and whose data were linked to a mortality database up to December 31, 2015.

The relationship between sleep duration and mortality risk was analyzed via a Cox proportional hazards regression model. Sleep duration was self-reported by participants who were asked how long they slept each day on average (≤ 5, 6, 7, 8, 9, or ≥10 h/day). Sex, age at diagnosis, duration of T2D, and treatment type were all examined as well.

In the study findings, absolute mortality rate was found to be higher in adults with T2D who reported either insufficient sleep of ≤ 5 h/day (215.0 per 10,000 person-years) or too much sleep of ≥ 10 h/day (363.5 per 10,000 person-years). Additionally, both shorter (≤ 5 h/day: HR, 1.24; 95% CI, 1.09-1.40; 6 h/day: HR, 1.13; 95% CI, 1.01-1.28) and longer sleep durations (8 h/day: HR, 1.17; 95% CI, 1.06-1.30; ≥ 10 h/day: HR, 1.83; 95% CI, 1.61-2.08) were associated with increased risk of all-cause mortality compared with the reference group (7 h/day).

Similar to findings on those with a younger age at diabetes onset, those with T2D who reported shorter sleep duration and were treated with both insulin and oral glucose-lowering medication were associated with greater risks of all-cause and CVD mortality.

There was no significant interaction between sleep duration and the presence of diabetes (P = .08). However, the researchers noted that a J-shaped relationship existed between sleep duration and all-cause mortality risk in those with T2D.

In concluding, the researchers said that because the association of sleep duration and mortality was more prominent in patients with T2D, especially those with younger age at disease onset, interventions may be warranted for these populations. “These individuals may require greater medical attention that targets sleep and lifestyle to reduce the risks of adverse health outcomes,” said the study authors.

Reference

Wang Y, Huang W, O’Neil A, et al. Association between sleep duration and mortality risk among adults with type 2 diabetes: a prospective cohort study. Diabetologia. Published online July 16, 2020. doi:10.1007/s00125-020-05214-4