Night Owls at Higher Risk of Diabetes, Study Finds
A recent study conducted by Brigham and Women’s Hospital has revealed that night owls face a higher risk of developing diabetes, with lifestyle choices playing a contributing role. The research, published in the Annals of Internal Medicine, suggests that individuals with later sleep and wake times have less healthy lifestyles and are more susceptible to diabetes compared to early-bird sleepers.
The study focused on the concept of “chronotype,” which refers to a person’s preferred timing of sleep and waking. The researchers found that individuals with an evening chronotype, meaning they go to bed late and wake up late, had a 19 percent increased risk of diabetes even after considering lifestyle factors. This suggests that lifestyle choices alone do not fully explain the link between chronotype and diabetes risk.
The study analyzed data from 63,676 female nurses participating in the Nurses’ Health Study II from 2009-2017. In addition to chronotype, the researchers examined diet quality, weight, body mass index (BMI), sleep timing, smoking behaviors, alcohol use, physical activity, and family history of diabetes. Diabetes status was determined based on self-reports and medical records.
The results revealed that approximately 11 percent of participants reported having an evening chronotype, while 35 percent identified as morning chronotypes, and the remaining population fell into the intermediate category. Evening chronotypes were associated with a 72 percent increased risk of diabetes before accounting for lifestyle factors. However, even after adjusting for lifestyle choices, evening chronotypes still faced a 19 percent increased risk.
The study also highlighted the differences between nurses who worked day shifts versus overnight shifts. The association between evening chronotype and diabetes risk was only observed in nurses working day shifts, indicating that work scheduling may play a role in the relationship between chronotype and diabetes risk.
While the study primarily focused on white female nurses, further research is needed to determine if these findings hold true for other populations. The study’s authors also acknowledge that the observed associations do not establish causality and that additional factors may contribute to a person’s chronotype and diabetes risk.
Moving forward, the researchers plan to investigate the genetic determinants of chronotype and its association with cardiovascular disease in larger and more diverse populations. If a causal link between chronotype and diabetes or other diseases can be confirmed, physicians could develop more tailored prevention strategies for their patients.
The study was funded by the National Institutes of Health and disclosed potential conflicts of interest related to consulting fees and equipment use in multicenter NIH research.
Reference:
“Chronotype, Unhealthy Lifestyle, and Diabetes Risk in Middle-Aged U.S. Women: A Prospective Cohort Study” by Sina Kianersi, DVM, PhD; Yue Liu, MD; Marta Guasch-Ferré, PhD; Susan Redline, MD, MPH; Eva Schernhammer, MD, DrPH; Qi Sun, MD, ScD and Tianyi Huang, ScD, MSc, 12 September 2023, Annals of Internal Medicine.
DOI: 10.7326/M23-0728