The link between sleep and the risk of developing obesity or type 2 diabetes is expected to be bidirectional. Research has shown that sleeping different amounts each night could be linked to diabetes risk. A new analysis of UK Biobank data reveals that increased variance in sleep duration is associated with an increased risk of diabetes, especially for those who slept longer and those with a lower genetic risk score for diabetes. Irregular sleep has been linked to type 2 diabetes risk, although this effect was reduced when data was adjusted for obesity, comorbidities, and lifestyle factors. Individuals with the most variability in how much they slept each night were found to be 59% more likely to develop diabetes over a 7.5-year follow-up period compared to those with a consistent sleep pattern.
To explore the link between irregular sleep and diabetes risk, researchers used UK Biobank data of 84,421 participants. Participants were invited to wear an accelerometer for seven days between 2013–2015 to capture activity levels and sleep data. The mean age of the participants was 62, and genetic data was used to calculate polygenic risk scores for diabetes. The study found that participants with a sleep duration deviation of between 31 and 45 minutes from their average had a 15% increased risk of diabetes, while those with a deviation of 91 minutes or more had a 59% increased risk after adjusting for age, sex, and race. The researchers also looked at differences in sleep duration of over and under 60 minutes and found a 34% increased risk for those with a difference of over 60 minutes, which decreased to 11% after adjusting for various lifestyle factors.
Sudha Tallavajhula, a neurologist, and sleep medicine physician at UTHealth Houston, who was not involved in the research, highlighted the hormonal pathways affected by sleep disorders. Poor sleep can contribute to impaired glucose and fat utilization, impacting metabolic health. There is a bidirectional relationship between sleep disorders, diabetes, and obesity. Sleep disorders can increase the risk of diabetes and obesity, while these conditions can also contribute to sleep disorders. Previous research has linked sleep disturbances to diabetes risk, and there is growing evidence supporting the impact of sleep variation on metabolic health. Disrupted circadian rhythms due to irregular sleep patterns could interfere with glucose metabolism and reduce insulin sensitivity, potentially leading to an increased risk of diabetes.
In a separate study, researchers looked at the role of circadian rhythm on type 2 diabetes risk by analyzing data from the Nurses’ Health Study II. They found that ‘night owls’ were more likely to develop type 2 diabetes than ‘early birds’. Chronotype, which describes an individual’s body clock, is linked to circadian rhythm and affected by light levels. ‘Night owls’ were also more likely to report unhealthy lifestyle behaviors, but the effect of chronotype on diabetes risk persisted even after adjusting for these factors. Healthy routines, including consistent sleep, regular physical activity, and balanced meals, are crucial for overall health and may help prevent type 2 diabetes. Becca Anne Krukowski, a professor of public health sciences at the University of Virginia School of Medicine, emphasized the importance of maintaining healthy routines to promote overall health and prevent chronic diseases like type 2 diabetes.