The association of initial and changes in serum A-FABP level with the development and improvement of pre-sarcopenia.

ABSTRACT

CONTEXT Several cross-sectional studies have reported the association between serum adipocyte fatty acid binding protein (A-FABP) level and pre-sarcopenia. However, data on the impacts of serum A-FABP level and its changes over time on the development and improvement of pre-sarcopenia are scarce. METHODS: This longitudinal cohort study included 1496 adults (41.2% men; median age, 58 [53-63] years) in 2013-2014 and was followed up to 2015-2016. Participants underwent serum A-FABP level measurements at baseline and follow-up visit. Visceral fat area (VFA) was measured using magnetic resonance imaging. Skeletal muscle mass (SMM) was estimated by bioelectrical impedance analysis and converted to skeletal muscle index (SMI). Pre-sarcopenia was defined as SMI < 1 standard deviation of the sex-specific mean for the young reference group. RESULTS: During an average follow-up period of 2.1 years, baseline serum A-FABP level was positively associated with the incidence of pre-sarcopenia (standardized by weight risk ratio [RR] 3.22, 95% confidence interval [CI] 1.96-5.38; standardized by VFA RR 2.11, 95%CI 1.29-3.51) and negatively associated with the improvement of pre-sarcopenia (standardized by weight RR 0.66, 95%CI 0.45-0.97; standardized by VFA RR 0.71, 95%CI 0.54-0.94), regardless of whether SMM was standardized by weight or VFA. Moreover, changes in serum A-FABP level provided additional information on the incidence and improvement of pre-sarcopenia, independent of baseline serum A-FABP level (all P < 0.05). CONCLUSIONS: Baseline serum A-FABP level and its changes were positively associated with the incidence, and negatively associated with the improvement of pre-sarcopenia.