The duration and structure of sleep may be associated with the risk of developing various diseases. This is the conclusion of Chinese researchers who followed the health of more than 95,000 adults for nine years.
The study was published in the journal PLOS Medicine.
A team led by Jingsong Luo of Peking University analyzed data from participants who wore sleep-monitoring devices on their wrists for seven days. The devices allowed the researchers to assess the duration of different sleep stages, including rapid eye movement (REM) sleep, deep sleep, and light sleep.
The researchers then compared this data with participants’ medical records and examined the associations between sleep characteristics and more than 1,000 diseases.
The largest number of associations was found for REM sleep, the stage during which dreams most often occur. Longer REM sleep was associated with a lower risk of 83 diseases, including heart failure, dementia, Parkinson’s disease, Alzheimer’s disease, and multiple sclerosis.
A greater amount of deep sleep, considered the most restorative sleep stage, was associated with a lower risk of seven diseases, including type 2 diabetes, severe depression, and sleep apnea.
The study also confirmed an association between nighttime sleep duration and disease risk. Participants who slept six to eight hours per night had the lowest risk levels for 69 diseases. Among people who slept less than five hours, an increased risk was observed for 37 diseases.
However, the study was observational. Therefore, its findings do not prove that a particular sleep duration or sleep structure directly prevents disease. The researchers identified statistical associations but could not establish a cause-and-effect relationship.
The authors note that further research is needed to understand how different stages of sleep may be associated with the development of diseases.
Follow NEWS.am Medicine on Facebook and Twitter