After previous research found a relationship between sleep duration and all-cause mortality among the general public, researchers wanted to study whether the effect would be present among those with diabetes. The new findings, published in the July 2020 issue of Diabetologia, found that to be true, and noted that participants who estimated a long sleep duration were at the highest risk for premature death. Chuanhua Yu, PhD, a biostatistics professor at Wuhan University in Wuhan, China, and his colleagues examined data from 248,817 adults without diabetes and 24,212 with type 2 diabetes, all of whom resided in the United States and participated in the National Health Interview Survey, a major data collection program of the National Center for Health Statistics and the Centers for Disease Control and Prevention (CDC) that has been in place for more than six decades. RELATED: Study Links Too Much Sleep to Early Death, Heart Risks The research team linked the information with mortality data and found that those who estimated a sleep duration of seven hours were least likely to die for any reason compared with those who estimated sleeping fewer or more hours. Sleeping too few or too many hours impacted mortality among those with and without diabetes, but the effect was stronger in the group with diabetes. “Although we may conclude that those who estimate sleeping more or less than seven hours are at higher risk, this study does not tell us why this is,” says Daniel Erichsen, MD, a sleep medicine physician at PeaceHealth in Eugene, Oregon, who was not involved in the research. “The results of this study are similar to noting that having ashtrays is associated with lung cancer. The association is true; however, a causal relationship between ashtrays and lung cancer has never been established.” Dr. Yu and his team were not available for comment, but in their published paper, they note extreme sleep may reflect poor health and reduced functioning, rather than poor sleep habits being a factor in participants’ health issues. For example, a person with a long list of diabetes-related complications may require more rest or long-term bed rest. Similarly, a study published December 2018 in the European Health Journal linked sleeping more than eight hours per day with higher mortality, but the authors noted it could indicate other health problems. Not getting enough sleep can throw off glucose metabolism and increase insulin levels, and put individuals at a higher risk for diabetes, according to past research. These same effects can worsen blood sugar management in those who already have the disease. RELATED: Why Does Type 2 Diabetes Make You Feel So Tired?
More Studies Are Needed to Prove a Cause-and-Effect Relationship
While seven hours of sleep per night may appear to be the optimal amount, “it is fallacious to arrive at a conclusion recommending that an adjustment of sleep duration to six to eight hours decreases mortality,” says Peter A. Fotinakes, MD, sleep expert and medical director at the Sleep Disorders Center at St. Joseph Hospital in Orange, California, who was not involved in the study. “A better conclusion is that sleep duration of less than six hours or greater than eight hours identifies a population with increased risk factors for comorbid conditions that should be identified and treated, such as sleep apnea,” says Dr. Fotinakes. “This is true for people with or without diabetes.” RELATED: Everything You Need to Know About Your Circadian Rhythm and How It Affects Sleep Sleep apnea, a disorder that interrupts breathing while you sleep, is common among individuals with diabetes and is correlated with obesity, according to a review published in the September–October 2017 issue of the Indian Journal of Endocrinology and Metabolism. Compared with people without this sleep disorder, Black Americans with sleep apnea had 14 percent higher blood glucose and less insulin sensitivity, according to a May 2020 study published in the Journal of the American Heart Association.
To Snooze Better and Potentially Live Longer, Try Changing Your Attitude About Sleep
The study authors, along with Drs. Erichsen and Fotinakes, note one limitation of this study is the lack of an objective measure of sleep. Those who report getting a good night’s rest typically overestimate their amount of sleep by one hour, while those who have sleep difficulties typically underestimate their sleep by about one hour, explains Erichsen. Another limitation is that the authors did not have any information on participants’ sleep quality and factors that may affect it, such as having young children at home or taking medications affecting sleep. The authors suggest future research should concentrate on addressing those issues, among others. Though the CDC recommends seven or more hours per night of sleep for adults ages 18 through 60, Erichsen notes worrying about how much you sleep can increase the risk for sleep-related anxiety and insomnia. Instead, he suggests being less worried about how long you should sleep, in order to allow good sleep to occur. RELATED: 9 Ways to Sleep Better When You Have Type 2 Diabetes
