Circulating Levels of Apelin, GDF-15 and Sarcopenia: Lack of Association in the MAPT Study.

ABSTRACT

OBJECTIVES: Apelin and GDF-15 have been proposed as biomarkers of age-related sarcopenia but evidence in human models is scarce. This study aimed to explore the associations between blood apelin and GDF-15 with sarcopenia incidence and the evolution of sarcopenia components over two years in older adults >70 years. DESIGN: Secondary longitudinal analysis of the Multidomain Alzheimer Preventive Trial. PARTICIPANTS: Older adults (>70 years) attending primary care centers in France and Monaco. SETTING: Community. MEASUREMENTS Serum Apelin (pg/mL) and plasma GDF-15 (pg/mL) were measured. Outcomes included sarcopenia defined by the European Working Group on Sarcopenia in Older People (EWGSOP) and its determinants (appendicular lean mass [ALM] evaluated through a Dual-energy X-ray Absorptiometry (DXA) scan, handgrip strength (HGS) and the 4-meter gait speed) measured over 2 years. Linear mixed models and logistic regression were used to explore the longitudinal associations. RESULTS: We included 168 subjects from MAPT (median age=76y, IQR=73-79; 78% women). Serum apelin was not significantly associated with sarcopenia incidence (OR=1.001;95%CI=1.000,1.001;p-value>0.05 in full-adjusted models) nor with ALM (ß=-5.8E-05;95%CI=-1.0E-04,2.12E-04;p>0.05), HGS (ß=-1.1E-04;95%CI=-5.0E-04,2.8E-04;p>0.05), and GS (ß=-5.1E-06;95%CI=-1.0E-05,2.0E-05;p>0.05) in fully adjusted models. Similarly, plasma GDF-15 was not associated with both the incidence of sarcopenia (OR=1.001,95%CI=1.000,1.002,p>0.05) and the evolution of its determinants ([ALM, ß=2.1E-05;95%CI=-2.6E-04,3.03E-04;p>0.05], HGS [ß=-5.9E-04;95%CI=-1.26E-03,8.1E-05; p>0.05] nor GS [ß=-2.6E-06;95%CI=-3.0E-05, 2.3E-05;p>0.05]) in fully adjusted models. CONCLUSIONS: Blood apelin and GDF-15 were not associated with sarcopenia incidence or with the evolution of sarcopenia components over a 2-year follow-up in community-dwelling older adults. Well-powered longitudinal studies are needed to confirm or refute our findings.