People with type 2 diabetes who nap for at least 30 minutes each day, regardless of their nightly sleep patterns, have an increased risk of developing metabolic dysfunction-associated fatty liver disease (MASLD), according to research presented Monday at the Endocrine Society’s annual meeting, ENDO 2026, in Chicago, Illinois.
MASLD, formerly known as non-alcoholic fatty liver disease (NAFLD), occurs when excess fat accumulates in the liver. This chronic disease can be caused by several diseases such as 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, doctors may be able to use simple sleep questions to identify people who are at higher risk of developing MASLD.
Our study suggests that long naps independently increase the likelihood of MASLD in patients with type 2 diabetes. However, poor nighttime sleep and long naps more than triple the risk of MASLD in this population. ”
Xuejiang Gu, MD, Ph.D., Executive Director, Department of Endocrinology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang Province, China
For the study, Gu and colleagues collected sleep data via questionnaires from 1,900 adults with type 2 diabetes between 18 and 85 years old from 2017 to 2024. The scientists divided participants into four sleep modes: short naps and good nighttime sleep, long naps and good nighttime sleep, short naps and poor nighttime sleep, and long naps and bad nighttime sleep. Team members used multivariate Cox regression analysis to examine associations between sleep characteristics and MASLD.
During an average follow-up period of just over 3 years, 379 new MASLD cases occurred. Compared to people in the group with better night sleep and shorter naps, participants in the other three categories were associated with a higher risk of MASLD.
Gu argues that sleep habits are daily modifiable behaviors that provide type 2 diabetes patients with a practical way to prevent MASLD.
“Our public health message to them is to nap smartly,” Gu said.
