New research identifies negative metabolic effects for people who are overweight and ignore their body’s signals to sleep at night.
To complete the study, the research team recruited 30 people with a BMI over 25 and collected saliva samples to determine the time at night when the individuals started producing melatonin, a hormone which initiates the process of falling asleep. The participants logged their sleep habits over the next week. From the logs, the researchers calculated the time difference between melatonin onset and average time of sleep and categorized the individuals into two groups: those who had a narrow window, with a short time between melatonin onset and sleep, and those with a wide window. A narrow window suggests someone who is staying awake too late for their internal body clock.
The results confirmed a variety of potentially harmful metabolic effects in the group with a narrow window, with specific differences between men and women. Men in this group had higher levels of abdominal fat and triglycerides in the blood, and higher overall metabolic syndrome risk scores than the men with better sleep habits. Women in this group had higher overall body fat percentage, glucose and resting heart rates.
The partially NHLBI-funded study was published in the Journal of Clinical Endocrinology & Metabolism.