How long we sleep and how well we sleep are both tied to metabolic health, which is how the body regulates cells and uses and stores energy.
While physical activity and diet habits can largely influence metabolism, scientists have found that improving sleep may help metabolism, preventing and even treating metabolic disorders such as diabetes and obesity.
"Get a good night’s sleep to help fight diabetes and obesity."
Sebastian Schmid, MD, with Department of Internal Medicine at the University of Lübeck, Germany, along with Manfred Hallschmid, PhD, and Bernd Schultes, MD, conducted a comprehensive review of research related to sleep loss and its effect on metabolism. Dr. Schmid and team reviewed research published between 1998 and 2013.
For example, these researchers referred to an analysis of data from the Adult Health and Behavior Project (AHBP) registry, including 1,214 Americans, ages 30 to 54. That investigation showed “a clear association between short sleep duration and an increased prevalence of the metabolic syndrome.”
Metabolic syndrome is the name for a group of risk factors that raise the risk for heart disease and other health problems, such as diabetes and stroke, according to the National Heart, Lung and Blood and Institute. These metabolic risk factors include a large waistline, a high triglyceride level (a type of of fat found in the blood), low HDL (“good”) cholesterol, high blood pressure and high blood sugar.
In this study, metabolic syndrome was detected in 22 percent of the entire participant population. Among short sleepers getting six to seven hours of sleep rather than seven to eight hours, the metabolic syndrome rate was more than double, affecting 48 percent. That number jumped to 83 percent for very short sleepers getting fewer than six hours of sleep per night.
Dr. Schmid and his colleagues also noted that too much sleep was not good for the body either. In the AHBP study, those snoozing more than eight hours a night also faced greater odds of having metabolic syndrome.
Similar results were observed in a US National Health Interview Survey that included more than 56,000 adults. The authors wrote that short-sleepers (less than seven hours per night) and long sleepers (more than eight hours per night) were more likely to have type 2 diabetes, hypertension, obesity and/or cardiovascular disease.
The authors pointed to sleep apnea as a specific type of sleep disturbance affecting metabolic health. With sleep apnea, an individual may experience pauses in breathing, stretches of shallow breathing or infrequent breathing while asleep.
Shift workers, who may work at night and sleep during the day, were spotlighted as a population that is susceptible to poor metabolic health and at increased risk of chronic illness and early death.
Experimental studies have shown some evidence that sleep loss may directly inhibit a body’s ability to process blood sugar, control food intake and maintain energy balance in the body, according to the investigators.
"These findings open up new strategies for targeted interventions aimed at the present epidemic of the metabolic syndrome and related diseases,” Dr. Schmid and team wrote. “Ongoing and future studies will show whether interventions to improve sleep duration and quality can prevent or even reverse adverse metabolic traits. Meanwhile, on the basis of existing evidence, health care professionals can be safely recommended to motivate their patients to enjoy sufficient sleep at the right time of day."
"The fact that short sleep duration, less than seven hours, results in metabolic syndrome should come as no surprise," said Robert Rosenberg, DO, of The Sleep Disorders Centers of Prescott Valley and Flagstaff in Arizona.
Dr. Rosenberg continued by saying, "Previous studies have shown a link between short sleep as well as sleep apnea and various components of metabolic syndrome such as diabetes, hypertension, and obesity. In fact, some in sleep medicine have begun to call metabolic syndrome "syndrome zzzz's.” As for long sleep resulting in an increased incidence of metabolic syndrome, this is new and certainly merits further investigation."
This review was published online March 25 in The Lancet Diabetes & Endocrinology.
This work was supported by grants from the Deutsche Forschungsgemeinschaft, the German Federal Ministry of Education and Research to the German Center for Diabetes Research, the Helmholtz Alliance Imaging and Curing Environmental Metabolic Diseases, the Initiative and Network Fund of the Helmholtz Association, the European Society of Endocrinology and the eSwiss Medical and Surgical Centre AG, St Gallen.