What you need to know: Circadian rhythm and metabolic disorders

The 2017 Nobel Prize in Physiology or Medicine will go to researchers for their work in discovery of molecular mechanisms controlling the circadian rhythm, which has been linked to a number of endocrine functions. Endocrine Today has compiled a list of recent news reports involving circadian rhythm and metabolic disorders.

The prize was awarded to Jeffrey C. Hall, PhD, and Michael Rosbash, PhD, both of Brandeis University, and Michael W. Young, PhD, of Rockefeller University, for their research explaining how “plants, animals and humans adapt their biological rhythm so that it is synchronized with the Earth’s revolutions,” according to a press release from the Nobel Assembly at Karolinska Institutet.

Shift work disrupts circadian rhythms, increases health risks in women

For many years, researchers have described the negative effect that shift work has on health.

Most of the literature has focused on the link between circadian rhythm disruptions and an increased risk for diabetes, cardiovascular disease and metabolic syndrome in men. Until now, the data on this association in women have been limited. Recent research, however, shows that women who work shifts are also at risk for this trio of health problems. Read more.

Elevated triglycerides ‘predominant marker’ for disrupted circadian rhythms in older adults

In older adults with overweight or obesity, elevated triglyceride levels are associated with increased circadian rhythm disruption, measured by reductions in both temperature amplitude and stability, according to findings published in the Journal of the Endocrine Society.

“Circadian rhythm disruption and metabolic syndrome are highly associated, but metabolic syndrome encompasses a variety of measurements, and it is still unclear how strongly each factor relates to temperature rhythms,” Brianna D. Harfmann, PhD, of the Barnstable Brown Diabetes and Obesity Center at the University of Kentucky in Lexington, and colleagues wrote. “Therefore, the goal of this study was to begin to identify which variables serve as the strongest predictors of two parameters of circadian rhythms, [temperature amplitude] and [temperature stability].” Read more.

Excessive daytime sleepiness, long naps related to increased risk for type 2 diabetes

Excessive daytime sleepiness and long naps may increase the risk for type 2 diabetes, while short naps do not increase the risk, according to study findings presented at the 51st European Association for the Study of Diabetes Annual Meeting.

In a meta-analysis of 10 studies published through November 2014 including 261,365 Western and Asian participants, researchers found that excessive daytime sleepiness and naps longer than 60 minutes per day each significantly increased the risk for type 2 diabetes by close to 50% when compared with absence of excessive sleepiness or long naps. Read more.

Light exposure at night could play role in obesity epidemic

Nighttime light exposure not only disrupts the body’s natural circadian rhythm but may also fuel increasing obesity rates in developed nations, according to a new review in Endocrine Reviews.

A growing body of evidence suggests pervasive exposure to electric light affects endogenously produced physiology and behavior fluctuations when it interferes with the circadian system, which is integral in regulating homeostatic functions such as energy regulation. Read more.

Diabetes risk higher for middle-aged adults who habitually stay up late

Diabetes, metabolic syndrome and sarcopenia were more likely to develop in people who prefer late nights than in early risers, even with the same amount of sleep, according to recent study findings.

“Regardless of lifestyle, people who stayed up late faced a higher risk of developing health problems like diabetes or reduced muscle mass than those who were early risers,” Nan Hee Kim, MD, PhD, of Korea University College of Medicine, said in a press release. “This could be caused by night owls’ tendency to have poorer sleep quality and to engage in unhealthy behaviors like smoking, late-night eating and a sedentary lifestyle.” Read more.