Getting up early can increase the risk of developing anorexia nervosa — an eating disorder characterized by low weight, food restriction, body image disturbances, fear of gaining weight. Studies have shown that having anorexia nervosa can lead to earlier waking. It also revealed a link between the risk of anorexia nervosa and insomnia.
Published in JAMA Network Open, the study found that anorexia nervosa is based on early rising, unlike many other disorders that are evening-based such as depression, binge eating disorder and schizophrenia.
Previous studies have suggested a possible link between eating disorders and the body’s internal clock, or circadian clock, which regulates a wide range of biological functions, such as sleep, and affects almost every organ in the body.
In the new study, an international team of researchers led by Massachusetts General Hospital (MGH) investigators found a bidirectional relationship between genes associated with anorexia nervosa and genes associated with morning chronotype (waking up early and going to bed early).
When they assessed the link to insomnia by creating a “genetic risk score” for anorexia nervosa, the scientists found that the genetic risk score was indeed associated with a higher risk of insomnia.
“Our findings implicate anorexia nervosa as a morning disorder, unlike other evening-based psychiatric disorders, and support the association between anorexia nervosa and insomnia as shown in previous studies,” said Hasan S. Dashti, an assistant investigator in the Department of Anesthesia, Critical Care at MGH. & Pain Medicine and Assistant Professor of Anesthesia at Harvard Medical School.
Treatment for anorexia nervosa is limited and current treatments have a relapse rate of up to 52 percent. Furthermore, the cause of the disease is still unclear. With anorexia nervosa having the second highest death rate among psychiatric disorders, more research is needed into new prevention strategies and treatments.
“The clinical implications of our new findings are currently unclear; However, our findings may guide future investigations into circadian-based therapies for the prevention and treatment of anorexia nervosa,” said lead author Hannah Wilcox, a researcher at MGH.