Weekend Catch-Up Sleep Linked to Less NAFLD

Getting good sleep or at least catching up on the weekend was associated with a lower risk for non-alcoholic fatty liver disease (NAFLD), a study from Korea found.

Among over 38,500 participants enrolled in a national Korean survey, multivariate logistic regression showed that averaging at least 7 hours of sleep a night had a significant negative association with NAFLD (OR 0.84, 95% CI 0.79-0.89) compared with less sleep.

The association was slightly stronger for women but significant for both genders (OR 0.86 and 0.91, respectively), reported Sangheun Lee, MD, PhD, of the Catholic Kwandong University College of Medicine in Gangneung, Korea, and colleagues in the Annals of Hepatology.

Compared with consistently not getting enough sleep, people who caught up on sleep on the weekends (less than 7 hours on weekdays but more than 7 hours on weekend days) and those who consistently slept for more than 7 hours each day had lower risks of developing NAFLD (OR 0.80, 95% CI 0.70-0.92; and OR 0.73, 95% CI 0.66-0.82; respectively).

Sleep duration has been associated with hypertension, diabetes mellitus, obesity, and cardiovascular disease. Insufficient sleep can lead to metabolic syndrome in those with chronic disease.

Not only is NAFLD associated with many of the same medical conditions, the group noted, but there are also plausible mechanisms linking NAFLD and poor sleep directly, such as dysregulation of cortisol, inflammatory cytokines, and norepinephrine as well as leptin and glucagon-like peptide-1.

“An inadequate sleep habit affects the hormone metabolism of the body, which can lead to obesity, metabolic syndrome, and NAFLD,” the researchers wrote.

While it’s not clear exactly how weekend catch-up sleep (WCUS) helps, “we have suggested that sleep supplementation during weekends may ease oxidative stress and inflammation in the liver,” they added.

For their study, Lee and colleagues examined Korea National Health and Nutrition Examination Survey (KNHANES) data on 38,702 patients enrolled in the ongoing survey from 2008 to 2019.

WCUS was defined as a sleep pattern occurring when participants did not get enough sleep during the week and compensated for it on the weekend by sleeping prolonged hours, which is a common sleep pattern and linked to obesity. Those who had cirrhosis, hepatitis B or C, liver cancer, irregular sleep, high alcohol consumption, or were under age 20 were excluded.

Mean weekday sleep duration was 6.8 to 6.9 hours, with 59% (n=22,851) averaging more than 7 hours daily. Mean weekend sleep duration was 7.7 hours.

About half of the survey respondents were men. The mean age was 48 to 49 and mean BMI was 24. Common comorbidities included obesity (32-35%), hypertension (27-29%), and hyperlipidemia (13-21%).

Mean aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels ranged from 21.8 to 23 IU/L and 21.4 to 23 IU/L, respectively. A lower total sleep duration was significantly linked to those who had ALT levels of 40 IU/L or greater.

NAFLD, determined by a hepatic steatosis index of 36 or greater, was present in approximately 23% of participants.

The authors acknowledged several limitations to the data, including its cross-sectional design. Biopsy or histological results were not available to validate a diagnosis of NAFLD.