Chicago—People with type 2 diabetes who nap longer than 30 minutes every day, regardless of their sleep patterns at night, increase their risk of developing metabolic dysfunction-associated steatotic liver disease (MASLD), according to a study being presented Monday at ENDO 2026, the Endocrine Society's annual meeting in Chicago, Ill.
MASLD, formerly known as nonalcoholic fatty liver disease (NAFLD), occurs when too much fat builds up in the liver. This chronic disorder may be caused by several conditions, including obesity and type 2 diabetes. The research team wanted to determine whether sleep behavior could be a better predictor of MASLD than standard medical tests. If so, physicians could use simple sleep questions to identify those at higher risk of developing MASLD.
"Our work suggests long naps independently increase the likelihood of MASLD in individuals with type 2 diabetes," said Xuejiang Gu, M.D., Ph.D., executive director of the Endocrinology Department at the First Affiliated Hospital of Wenzhou Medical University in Wenzhou, Zhejiang, China. "However, poor nocturnal sleep combined with long naps more than triples MASLD risk in this population."
For this study, Gu and colleagues collected sleep data by questionnaire from 1,900 adults with type 2 diabetes, aged 18-85 years old, between 2017 and 2024. The scientists divided the participants into four sleep modes: good nocturnal sleep with short nap, good nocturnal sleep with long nap, poor nocturnal sleep with short nap, and poor nocturnal sleep with long nap. Team members used Multivariate Cox regression analysis to examine the association between sleep characteristics and MASLD.
During the average follow-up time of a little more than three years, 379 new MASLD cases arose. Compared with people in the good nocturnal sleep with short nap group, participants in the other three categories were associated with a higher risk of MASLD.
Gu maintains that sleep habits are daily, modifiable behaviors that offer people with type 2 diabetes a practical way to prevent MASLD.
"Our public health message to them is to nap wisely," Gu said.
