August 05, 2022
3 min read
Adults who go to sleep later, snore and nap for more than 30 minutes during the day are more likely to develop metabolic dysfunction-associated fatty liver disease, according to study findings.
In a study published in The Journal of Clinical Endocrinology & Metabolism, researchers analyzed liver ultrasounds and self-reported sleeping behaviors in a cohort of adults from China. Those who reported having a poor sleep quality were more likely to develop metabolic dysfunction-associated fatty liver disease (MAFLD), and each 1-point improvement in sleep quality score reduced the risk for MAFLD by 16%.
“An easy-to-use healthy sleep score algorithm is proposed to assess the overall sleep quality in clinical setting and is of value in identifying individuals at high risk for fatty liver disease,” Yan Liu, PhD, associate professor in the department of nutrition, School of Public Health at Sun Yat-sen University in Guangzhou, China, and in nutrition and health at the Gunagdong Provincial Key Laboratory of Food; Min Xia, PhD, dean of the School of Public Health at Sun Yat-sen University and director of nutrition and health at the Guangdong Provincial Key Laboratory of Food; and Wei Zhu, PhD, of the department of toxicology at the Guangzhou Center for Disease Control and Prevention, told Healio. “Considering the large proportion of individuals suffering from poor sleep quality in modern society, sleep quality should be integrated into the comprehensive lifestyle management for the prevention of metabolic disorders, including fatty liver disease.”
Researchers conducted a cross-sectional study of 5,011 adults aged 30 to 79 years living in southern China who participated in the South China Cohort study’s baseline survey. All participants underwent a liver ultrasound at baseline. Adults were diagnosed with MAFLD if hepatic steatosis was present on the ultrasound and the participants also had overweight or obesity, diabetes or evidence of metabolic dysregulation. Sleep behaviors were self-reported. Low-risk sleep factors were defined as going to bed before 11 p.m., sleeping 7 to 8 hours each night, having rare or no instances of insomnia or snoring, having no frequent daytime sleepiness, and napping less than 30 minutes per day. Participants received a score of 1 for each low-risk sleep factor they reported. All six components were added together for a healthy sleep score ranging from 0 to 6, with a higher score indicating better sleep quality.
Snoring, napping increase MAFLD odds
Of the study cohort, 28.4% were diagnosed with MAFLD. Adults who had a late bedtime (adjusted OR = 1.37; 95% CI, 1.1-1.7) snored (aOR = 1.59; 95% CI, 1.33-1.91) and napped during the day for longer than 30 minutes (aOR = 1.17; 95% CI, 1.02-1.35) had an increased likelihood for developing MAFLD. Snoring had the strongest effect, with occasional snorers having 48% higher odds for MAFLD compared with those who did not snore (OR = 1.48; 95% CI, 1.16-1.87). Adults who had poor nocturnal sleep and napped more than 30 minutes during the day had higher odds for MAFLD compared with those with healthy nocturnal sleep who napped less than 30 minutes during the day (aOR = 2.38; 95% CI, 1.73-3.27).
Healthy sleep reduces MAFLD risk
Each 1-point increase in healthy sleep score was associated with a 16% reduction in odds for developing MAFLD (aOR = 0.84; 95% CI, 0.8-0.89). Adults with an intermediate sleep quality score of 3 or 4 (aOR = 0.71; 95% CI, 0.55-0.91) and those with a good sleep quality score of 5 or 6 (aOR = 0.55; 95% CI, 0.42-0.71) were less likely to develop MAFLD than those with a poor sleep quality score of 2 or less (P for trend < . 001). A 1-point improvement in sleep quality lowered the odds for MAFLD in adults with low physical activity levels (aOR = 0.8; 95% CI, 0.72-0.89) and central obesity (aOR = 0.82; 95% CI, 0.76-0.87).
BMI mediated 20.77% of the effect of sleep quality on MAFLD risk. Among individual sleep behaviors, snoring was the only one to have a direct effect on MAFLD risk.
“More research in longitudinal cohorts and randomized clinical trials should be conducted to examine the associations observed in our study,” Liu, Xia and Zhu said. “Additionally, experiments in preclinical models should also be carried out to explore the molecular mechanisms through which poor sleep quality, either alone or in combination, contributes to the development of fatty liver.”
For more information:
Yan Liu, PhD, can be reached at email@example.com.
Min Xia, PhD, can be reached at firstname.lastname@example.org.
Wei Zhu, PhD, can be reached at email@example.com.