June 10, 2019Metabolism
According to an article published in Diabetes Care (5 June 2019), a study has found that not sticking to a regular bedtime and wakeup schedule -- and getting different amounts of sleep each night -- can put a person at higher risk for obesity, high cholesterol, hypertension, high blood sugar and other metabolic disorders. The study noted that for every hour of variability in time to bed and time asleep, a person may have up to a 27% greater chance of experiencing a metabolic abnormality.
For the study, the authors followed 2,003 men and women, ages 45 to 84, participating in the NHLBI-funded Multi-Ethnic Study of Atherosclerosis (MESA). The participants were studied for a median of six years to determine the associations between sleep regularity and metabolic abnormalities. To ensure objective measurement of sleep duration and quality, participants wore actigraph wrist watches to closely track sleep schedules for seven consecutive days. They also kept a sleep diary and responded to standard questionnaires about sleep habits and other lifestyle and health factors. Participants completed the actigraphy tracking between 2010 and 2013 and were followed until 2016 and 2017.
Results showed that individuals with greater variations in their bedtimes and in the hours they slept, had a higher prevalence of metabolic problems, and these associations persisted after adjusting for average sleep duration. This was also the case when they looked at the participants who developed metabolic disorders during the 6.3 years of follow up. The prospective results also showed that the variations in sleep duration and bedtimes preceded the development of metabolic dysfunction. According to the authors, this provides some evidence supporting a causal link between irregular sleep and metabolic dysfunction. Participants whose sleep duration varied more than one hour were more likely to be African-Americans, work non-day shift schedules, smoke, and have shorter sleep duration. They also had higher depressive symptoms, total caloric intake, and index of sleep apnea. Increasing sleep duration or bedtime variability was strongly associated with multiple metabolic and simultaneous problems such as lower HDL cholesterol and higher waist circumference, blood pressure, total triglycerides, and fasting glucose.
According to the authors, their results suggest that maintaining a regular sleep schedule has beneficial metabolic effects, and that this message may enrich current prevention strategies for metabolic disease that primarily focus on promoting sufficient sleep and other healthy lifestyles.