Plasma Leukocyte Cell-Derived Chemotaxin-2 as a Risk Factor of Sarcopenia: Korean Frailty and Aging Cohort Study

<b>Background/Objective:</b> Leukocyte cell-derived chemotaxin-2 (LECT2), a hepatokine, is implicated in non-alcoholic fatty liver disease (NAFLD). Although NAFLD and sarcopenia are closely linked, the relationship between plasma LECT2 levels and sarcopenia remains unclear. <b>Methods:</b> We analyzed plasma LECT2 levels in 400 older adults aged 70-84 years old living in the community enrolled in the Korean Frailty and Aging Cohort Study. The appendicular skeletal muscle mass (ASM) and handgrip strength (HGS), both adjusted for the BMI, were used to evaluate the muscle mass and strength. A low muscle mass (LMM) was defined using the sex-specific lowest quintile of ASM/BMI as the cutoff value, while a low muscle strength (LMS) was determined based on the lowest quintile of the HGS/BMI. Sarcopenia was defined by the coexistence of an LMM and LMS. <b>Results:</b> NAFLD was identified using a fatty liver index > 30. The participants with NAFLD had significantly higher plasma LECT2 levels compared to their non-NAFLD counterparts (34.4 [29.3-41.1] vs. 29.0 [24.7-36.7] ng/mL, <i>p</i> < 0.001). Circulating LECT2 levels were inversely correlated with ASM/BMI (<i>r</i> = -0.506, <i>p</i> < 0.001) and HGS/BMI (<i>r</i> = -0.474, <i>p</i> < 0.001), as determined by Spearman correlation analysis. Among the study participants, 79 (19.8%) were categorized as having either an LMM or LMS, and 31 (7.8%) were identified as having sarcopenia. In multivariate logistic regression, the highest LECT2 quartile had markedly greater odds of an LMM (OR 3.31, 95% CI 1.41-7.75), LMS (OR 2.85, 95% CI 1.29-6.26), and sarcopenia (OR 5.48, 95% CI 1.57-19.05) relative to the lowest quartile. <b>Conclusions:</b> Our results indicate that elevated plasma LECT2, a hepatokine increased in NAFLD, contributes to an increased risk of sarcopenia in older adults.