A research group led by Professor Mayumi Yamamoto and Takao Miwa, a physician, of the Health Administration Center at Gifu University has demonstrated that body composition is associated with metabolic dysfunction-associated fatty liver disease (MAFLD) and nonalcoholic fatty liver disease (NAFLD) in young adult males. The research group examined factors related to MAFLD and NAFLD among 335 male graduate students who attended a health checkup. Obesity was found to be an important factor in fatty liver disease among these young men. These findings are expected to contribute to the development of preventive measures against fatty liver disease in the young generation. The study results were published in the international scientific journal Hepatology Research (Volume 53, Issue 8).
The study included 335 male graduate students who attended a health checkup upon entering Gifu University. Abdominal ultrasonography, bioelectrical impedance analysis for body composition estimation, and hand grip strength measurement were performed, and factors (including body composition) associated with the current NAFLD or MAFLD status were examined. MAFLD was defined as fatty liver disease with comorbid obesity, type 2 diabetes mellitus, or two or more metabolic abnormalities. The median age of the participants was 22 years, and their median body mass index (BMI) was 21 kg/m². In total, 9% of the students were diagnosed with obesity (BMI ≥ 25 kg/m²).
According to the abdominal ultrasonography findings, 17% of the participants had a fatty liver, 8% had MAFLD, and 16% had NAFLD. Moreover, 8% of the participants had both MAFLD and NAFLD. The multivariate analyses based on age, skeletal muscle mass, body fat mass, and hand grip strength, which were performed to evaluate the association of body composition with MAFLD and NAFLD, showed body fat mass to be an independent factor for both diseases.
The same multivariate analyses performed for the non-obese participants also demonstrated body fat mass as an independent factor for MAFLD and NAFLD. The results suggest that 'masked obesity' (defined as a state of fat accumulation despite a BMI value in the normal range) is an important factor for fatty liver disease in young adult males.
Next, decision tree analyses based on age, BMI, skeletal muscle mass, body fat mass, and hand grip strength were performed. For the total participants, BMI was extracted as a factor for MAFLD and NAFLD, whereas for the non-obese participants, BMI and skeletal muscle mass were extracted as the first and second factors, respectively. These results indicate that BMI can be a simple index for MAFLD and NAFLD. Furthermore, besides fat accumulation, skeletal muscle mass contributes to the pathology of fatty liver disease.
Additionally, the researchers performed a random forest analysis based on blood test markers representing endocrine metabolic abnormalities and body composition measures. As a result, the highest contributing factor to MAFLD and NAFLD development was the BMI for the total participants and the serum triglyceride level for the non-obese participants.
Miwa stated, "By focusing on body composition, our study demonstrated that some young adult males with a BMI value in the normal range manifest so-called masked obesity, which has a great impact on the fatty liver disease pathology. Moreover, a decrease in skeletal muscle mass and an increase in the triglyceride level greatly contribute to the pathology. Our findings suggest that early detection of fatty liver disease through opportunities such as health checkups as well as tailored nutrition and exercise educational activities for the young generation are important for extending their healthy life expectancy."
Journal Information
Publication: Hepatology Research
Title: Impact of body fat accumulation on metabolic dysfunction-associated fatty liver disease and nonalcoholic fatty liver disease in Japanese male young adults
DOI: 10.1111/hepr.13906
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