Sleep Duration and Risk of Premature Death in Patients with T2DM

Both sleep deprivation and excessive sleep duration may be independent risk factors for premature death in patients with T2DM.  

According to the National Sleep Foundation (NSF), the recommended amount of daily sleep varies depending on age and health status. The NSF recommends 7-9 hours of sleep for adults 18-64 and 7-8 hours for adults ≥65.¹ Sleep duration has been identified as a risk factor for impaired glycemic control. Too much or too little sleep can negatively impact glucose control in patients with T2DM.² In general, these observations occurred in studies of individuals who slept on average four and a half to six hours per night. Long term sleep deviations of <5 hours/day or >9 hours/day have been associated with increased mortality and cardiovascular disease.³ Multiple explanations have been proposed to explain this relationship between sleep duration and glycemic control. These include decreased insulin release, increased cortisol levels, increased insulin resistance, and appetite stimulation.⁴   

To further investigate the relationship between chronic sleep deviations and premature death in patients with T2DM, Wang and colleagues conducted a prospective cohort study. The findings from this study were recently published in Diabetologia.⁵  In their study Wang and colleagues analyzed data from 273,029 adult participants from the National Health Interview Survey (2004-2013) who had data linked to a mortality database. A total of 24,212 participants with T2DM were included in the analysis. The outcomes of interest were all-cause death and death due to one of the following specific causes: heart disease, stroke, cancer, chronic lower respiratory disease, Alzheimer’s Disease, diabetes, influenza and pneumonia, and kidney disease. Participants were asked, “On average, how many hours of sleep do you get in a 24 h period” and provided the following sleep duration categories: ≤5, 6, 7, 8, 9, and ≥10 hours/day. A participant was considered to have an extreme sleep duration if they selected either ≤ 5 or ≥10 hours/day categories. A multivariate Cox proportional hazards regression model was used to estimate hazard ratios (H.R.), and 95% confidence intervals (CI) were used to test the association between sleep duration and outcomes of interest, using the 7 hours group as the reference.⁵  

An increased risk of all-cause death was observed in patients with and without diabetes who reported extremes of sleep duration. The highest increased risk was observed in individuals with T2DM who reported either extreme of sleep duration, when compared to patients without T2DM who slept 7 hours/day (≤5 hours/day HR 1.63 [95% CI 1.24, 2.13]; ≥ 10 hours/day HR 2.17 [1.72, 2.73]). Among patients with T2DM, either of the extreme sleep durations was associated with an increased risk of death compared to patients who slept 7 hours/day (≤5 hours/day HR 1.24 [95% CI 1.09, 1.40]; ≥ 10 hours/day HR 1.83 [95% CI 1.61, 2.08]). In individuals who reported ≤5 hours/day, there was a significantly increased risk of cancer and kidney disease-related death. In those who reported ≥10 hours/day, there was a significant increased risk of death due to all specific causes of death except influenza and pneumonia.⁵   

Subgroup analysis exploring the impact of age of diabetes onset and extreme sleep duration on all-cause mortality found the highest associated risk in patients who develop diabetes before 45 years of age, compared to after 45 years. The association of the duration of diabetes and all-cause mortality was also explored. In the group that reported a sleep deficit of ≤5 hours/day, those living with diabetes for longer than 20 years had the highest risk of all-cause death. In participants who slept ≥10 hours/day, the highest risk of death was observed in those living with diabetes for 11-20 years.⁵   

These findings suggest that sleep deprivation or excess may be an independent risk factor for premature death among patients with T2DM. This association was the strongest in patients who reported sleep duration ≥ 10 hours/day, diabetes onset before age 45, and longer diabetes duration. Patients with T2DM may benefit from education about the NSF recommended sleep guidelines, monitoring of sleep duration, and appropriate sleep interventions to reduce premature death risk.   

Practice Pearls:  

• Patients with T2DM who sleep ≤ 5 hours or ≥ 10 hours may be at an increased risk of premature death.  
• Early-onset and longer diabetes duration may place patients with T2DM who sleep ≤ 5 hours or ≥ 10 hours at an even higher risk of premature death.   
• Monitoring sleep duration and developing interventions when needed to improve sleep in patients with T2DM may reduce premature death.   

1. “How much sleep do we really need?” National Sleep Foundation. Updated, July 30, 2020. Available at https://www.sleepfoundation.org/articles/how-much-sleep-do-we-really-need. Assessed on July 30, 2020.   
2. Lee, Shaun Wen Huey et al. “The impact of sleep amount and sleep quality on glycemic control in type 2 diabetes: A systematic review and meta-analysis.” Sleep medicine reviews vol. 31 (2017): 91-101. doi: 10.1016/j.smrv.2016.02.001  
3. Williams Catherine J, et al. “Sleep Duration and Snoring in Relation to Biomarkers of Cardiovascular Disease Risk Among Women With Type 2 Diabetes.” Diabetes Care vol. 30,5 (2007): 1233-1240. doi: https://doi.org/10.2337/dc06-2107  
4. “The Link Between a Lack of Sleep and Type 2 Diabetes”. National Sleep Foundation. Updated, July 30, 2020.  Available at https://www.sleepfoundation.org/articles/link-between-lack-sleep-and-type-2-diabetes. Assessed on July 30, 2020.  
5. Wang Yafeng. Association between sleep duration and mortality risk among adults with type 2 diabetes: a prospective cohort study. Diabetologia (2020). https://doi.org/10.1007/s00125-020-05214-4  

Louise Brown, PharmD Candidate, University of Colorado Skaggs School of Pharmacy and Pharmaceutical Sciences