Adults Need a Regular Bedtime, Too

A study published in Scientific Reports found adults with a regular bedtime are more likely to weigh less and to have lower blood sugar, risk of heart disease, and diabetes than those who do not, reports Reuters . Analysis of the sleep cycles of nearly 2,000 adults, average age 69 years, employed a new metric called the Sleep Regularity Index. The index examines sleep variation across a 24-hour day and compares one day to the next to measure regular sleep and wake times in addition to midday naps. The investigators found people with high sleep irregularity tended to go to bed later, sleep more during the day, and less at night than regular sleepers. They also have less light exposure and higher daytime sleepiness. More sleep irregularity also correlated with a higher 10-year risk of heart disease and greater obesity, hypertension, fasting glucose, and diabetes. The study also linked sleep irregularity to higher levels of stress and depression. African Americans were most likely to have the greatest sleep irregularity. Duke University Medical Center's Jessica Lunsford-Avery recommends that future studies consider mechanisms that connect sleep irregularity and disease risks, along with cause-and-effect relationships.