Night owls at increased risk of diabetes, metabolic syndrome
People who stay up late at night are at increased risk of diabetes and other health problems, according to new research.
The study included 1,620 people between the ages of 47 and 59 who took part in a large research study in Korea. The participants answered questions about their sleep quality, sleep-wake cycles, and lifestyle habits. All participants underwent an oral glucose tolerance test for diabetes, a visceral obesity diagnosis, and a body composition measurement. They were then grouped into three categories -- morning types (480), evening types (95), or in between (1,045).
Researchers found that the evening types were more likely than the morning types to have poor sleep quality and engage in unhealthy lifestyle habits such as smoking, eating late or night, or being sedentary.
Night owls were 1.7 times more likely to have Type 2 diabetes and metabolic syndrome than early risers. Metabolic syndrome is a cluster of conditions -- including a high blood sugar level, increased blood pressure, abnormal cholesterol levels, and excess body fat around the waist -- that occur together. People who sleep late were also 3.2 times more likely to develop sarcopenia -- a gradual loss of muscles mass - than early risers. The increased risks still applied even if the night owls got the same amount of sleep as early birds.
The study also found that night owls did less regular exercise than early risers. Men who slept late were more likely to have sarcopenia and diabetes than their counterparts, and women who slept late had more belly fat and an increased risk of metabolic syndrome.
Night owls were more likely to be younger, female, and current smokers.
"Considering many younger people are evening chronotypes, the metabolic risk associated with their circadian preference is an important health issue that needs to be addressed," said senior author Dr. Nan Hee Kim, an endocrinologist at Korea University Ansan Hospital.
The study was published in the Journal of Clinical Endocrinology and Metabolism.