Low muscle mass is linked with presence of non-alcoholic fatty liver disease irrespective to central obesity: highlights from a prospective epidemiological study in Greece

Abstract

Abstract Background/Introduction The association between sarcopenia and nonalcoholic fatty liver (NAFL) is highlighted in recent epidemiological studies, although results remain inconsistent. Purpose This study aimed to examine the association of low skeletal muscle mass with NAFL as well as the potential mediating effect of waist circumference on the examined association. Methods At baseline, 3,042 participants from the Attica region of Greece were recruited. NAFL was assessed through hepatic steatosis index (HSI). Skeletal muscle mass index (SMI) was indirectly calculated using a standard validated procedure. Results Ranking from 1st to 3rd SMI tertiles NAFL rate was 45%, 33% and 22%, respectively (p<0.001). Multi-adjusted logistic regression analysis revealed that participants assigned in the 2nd (Odds Ratio (OR): 0.50, 95% Confidence Interval (95% CI): 0.41–0.61)) and 3rd SMI tertile had 50% and 76% (OR: 0.24, 95% CI: 0.19–0.29) lower likelihood to have NAFL compared with their 1st tertile counterparts. This association remained robust after multiple adjustments; however, significance was marginally lost, when waist circumference was added to the model. Subsequently, a multi-adjusted dose-response analysis between SMI and NAFL was performed in the total sample, as well as in the subcategories of normal and abnormal waist circumference. In the total sample, a significant inverse association between SMI and NAFL was observed [OR (per 2 points increase in SMI) = 0.94 (95% CI: 0.92–0.95); p=0.001]. When categorized by waist circumference, participants with moderate/high SMI and normal waist circumference had the lowest NAFL rates (24.3%). Those with low SMI and normal waist circumference and those with moderate/high SMI and abnormal waist circumference had similar rates of NAFL (47.4% and 50.3%, respectively; p=0.25). Participants with both low SMI and abnormal waist circumference presented the highest NAFL rate (60.5%), which was significantly higher compared with the rest subgroups (p<0.001). These findings were confirmed in multi-adjusted analysis to assess NAFL odds per case: participants with adnormal waist, [OR (per 2 points increase in SMI) = 0.97 (95% CI: 0.94–1.00)] vs. participants with normal waist [OR (per 2 points increase in SMI) = 0.89 (95% CI: 0.84–0.95)]. Conclusions Increasing SMI was associated with lower rates of NAFL independently to abdominal obesity, whereas the two interact as key determinants of NAFL. Funding Acknowledgement Type of funding sources: Other. Main funding source(s): Hellenic Society of Cardiology