- New study analyzes how irregular sleeping patterns affect future metabolic abnormalities.
- Every 1-hour increase in sleep variability can double the odds of hypertension, obesity high blood sugar, and high cholesterol.
Modern lifestyle and environment — such as excessive use of electronic devices, night activities, and increased light exposure — has not only deprived people of sufficient sleep but also significantly disturbed the regularity of sleep behaviors.
Previous studies have shown that an adequate amount of sleep is associated with diabetes, obesity, and metabolic syndrome. However, less is known about the impact of irregular sleep (high variability in day-to-day sleep timing and duration).
Now, researchers at the U.S. Department of Health & Human Services have published a paper explaining the link between inconsistent sleep patterns and metabolic abnormalities. They found that every 1-hour increase in sleep variability can double the odds of multiple metabolic abnormalities.
They analyzed the data of 2,003 adults aged between 45 and 84, who participated in the Multi-Ethnic Study of Atherosclerosis. These participants were studied for 6 years: they were asked to wear actigraph wrist watches (that monitor human rest/activity cycles) for 7 consecutive days and write their sleep durations in a diary.
Their sleep patterns and other health and lifestyle factors were also taken into account. All actigraph records were tracked between 2010 and 2013 and were followed until 2017.
The big strength of this research is objective metrics and a broad range of samples. The study doesn’t only look into the current factors but also analyzes how irregular sleeping patterns affect future metabolic abnormalities.
The findings show that people with higher variations in their bedtime and wake-up schedules had a higher prevalence of metabolic issues. What’s more surprising is that these associations didn’t change even after increasing average sleep duration.
The results suggest that not sticking to regular bedtimes can put people at higher risk for metabolic dysfunction and simultaneous problems such as total triglycerides, higher waist circumference, and lower HDL cholesterol.
More specifically, every 1-hour increase in the sleep timing was associated with 23% higher odds of metabolic syndrome, and every 1-hour increase in sleep duration was associated with 27% higher odds.
Higher rates of variable sleep (more than one hour) were observed in African Americans, shift workers, and smokers. These participants also had more caloric intake, higher depressive symptoms and a serious sleep disorder called sleep apnea.
The study also includes evidence where more consistent sleeping patterns are linked with more favorable metabolic profiles. This suggests that maintaining a regular sleep pattern has beneficial metabolic effects.
We need more such studies to precisely measure the interventions on long- or short-term improvements in the metabolic profiles, and to detect behavioral approaches that enhance and maintain consistent sleep across population groups.