Inconsistent Sleep May Heighten Older Adults’ Risk of Diabetes

Consistent sleep patterns may help prevent type 2 diabetes, according to new research published in Diabetes Care.¹

In the study led by Brigham and Women’s Hospital, researchers monitored patients’ sleep patterns for a week and followed up with them for more than 7 years. The study included 84,421 participants from the United Kingdom (UK) Biobank who provided accelerometer data—used to determine sleep habits—between 2013 and 2015 and did not have diabetes at the time. Patients had a mean (SD) age of 62 (8) years, were mostly female (57%), and were predominantly White (97%).

The study revealed that irregular sleep durations were linked to a higher risk of diabetes, with those experiencing the greatest sleep irregularity having a 34% higher risk than their peers. In total, there were 2058 incident cases of diabetes across 622,080 person-years of follow-up.

Compared with patients whose sleep varied by 30 minutes or less each night, the risk of developing diabetes increased by:

Older adults with the greatest sleep irregularity had a 34% higher risk of developing diabetes compared with their peers | Image credit: Pixel-Shot – stock.adobe.com

• 15% for those with 31 to 45 minutes of variation
• 28% for those with 46 to 60 minutes of variation
• 54% for those with 61 to 90 minutes of variation
• 59% for those with over 90 minutes of variation

These results accounted for differences in age, sex, and race. The researchers also found that the risk increase was nonlinear (P nonlinearity = .0002) and indicated a sharper rise in diabetes risk for those with more than 60 minutes of sleep variation compared with those with 60 minutes or less, with the former having a 34% higher risk of type 2 diabetes (95% CI, 1.22-1.47).

However, this risk increase dropped to 11% after factoring in lifestyle, existing health conditions, environmental factors, and body fat. According to the researchers, the link became weaker as these factors were considered, but was more significant in patients with a lower genetic risk for diabetes or who generally slept longer.

According to Sina Kianersi, PhD, research fellow at Brigham and Women's Hospital and lead author of the study, this research has helped identify a modifiable lifestyle factor that can be adjusted to help reduce the risk of developing diabetes, emphasizing the importance of regular sleep.

“Our findings have the potential to improve diabetes prevention on multiple levels,” Kianersi said in a news release.² “Clinically, they might inform better patient care and treatment plans. Public health guidelines could promote regular sleep patterns. However, more research is needed to fully understand the mechanism and confirm the results in other populations."

Irregular sleep duration can increase the risk of diabetes by disrupting the body's circadian rhythms, which regulate insulin secretion and glucose metabolism. When sleep patterns are inconsistent, it leads to unstable daily routines, which in turn can affect light exposure and meal timing and lead to reduced insulin sensitivity and poor glucose control, which can further result in diabetes and other metabolic issues. Irregular sleep is also linked to poor sleep quality, extreme sleep durations, and evening chronotypes, all of which are associated with a higher risk of diabetes.

“Further, irregular sleep may interrupt behavioral rhythms and induce unhealthy habits, such as disrupted mealtime, irregular exercise timing, and late-night snacking, which are emerging risk factors for cardiometabolic disease,” the researchers added. “Other pathways through which irregular sleep duration may cause cardiometabolic outcomes are inflammation, gut dysbiosis, hypothalamic-pituitary-adrenal axis dysfunction, and autonomic dysfunction.”

Type 2 diabetes affects nearly half a billion people globally and ranks among the top 10 causes of death and disability. Projections have indicated the number of people with type 2 diabetes could more than double from 529 million to 1.3 billion by 2050, underscoring the urgency for innovative prevention strategies.³ Researchers do not anticipate that any countries will see a drop in age-standardized diabetes rates over the next 30 years.

The current study noted some limitations.¹ Certain lifestyle information was collected up to 5 years before the accelerometer study began, potentially affecting result accuracy. The researchers also noted that assessing sleep duration based on 7 days may not reflect long-term sleep patterns. Additionally, most participants were generally healthy, older, and White, which may limit the generalizability of these findings to more diverse populations.

According to the researchers, future research will focus on younger participants and those from diverse racial backgrounds, as well as exploring the biological mechanisms behind the link between sleep irregularity and diabetes risk.

References

1. Kianersi S, Wang H, Sofer T, et al. Association between accelerometer-measured irregular sleep duration and type 2 diabetes risk: a prospective cohort study in the UK biobank. Diabetes Care Published online July 17, 2024. doi:10.2337/dc24-0213
2. Study finds irregular sleep patterns lead to increased risk of type 2 diabetes. News release. Brigham and Women’s Hospital. July 17, 2024. Accessed July 17, 2024. https://www.eurekalert.org/news-releases/1051463
3. Klein HE. Diabetes prevalence expected to double globally by 2050. AJMC®. June 22, 2023. Accessed July 17, 2024. https://www.ajmc.com/view/diabetes-prevalence-expected-to-double-globally-by-2050