Sarcopenia is a pathological condition affecting the development and progression of
NAFLD. Urinary levels of
titin-N fragment, a
biomarker reflecting muscle damage, were measured in
NAFLD subjects, and analyzed in a retrospective manner for possible correlations with
NAFLD pathophysiology to assess their clinical relevance. This study enrolled 153
NAFLD subjects and 100 subjects without
NAFLD,
obesity or
diabetes mellitus (non-
NAFLD).
NAFLD subjects had more decreased knee extension strength.
NAFLD subjects had greater subcutaneous fat thickness and echo intensity (brightness) of the rectus femoris muscle on ultrasound images; higher levels of the intra- and extra-myocellular
lipids (IMCL, EMCL) using 1H-MRS. Urinary
titin-N fragment levels were increased with increasing age but not different between males and females.
NAFLD subjects had higher
titin-N fragment levels than non-
NAFLD subjects. The levels were negatively correlated with skeletal muscle mass and knee extension strength and positively correlated with muscle echo intensity, EMCL, and
liver fibrosis scores (
NAFLD fibrosis score, FIB-4 index). Multivariate analysis revealed that factors affecting the levels were skeletal mass index, leg skeletal muscle mass, liver stiffness, and
NAFLD fibrosis score. Urinary levels of
titin-N fragment reflected skeletal muscle deterioration and functional decline, and was closely associated with hepatic pathological conditions in
NAFLD subjects.