Critical analytical evaluation of promising markers for sarcopenia

Publication date: Available online 8 December 2015 Source:European Geriatric Medicine Author(s): E. Cavalier, C. Beaudart, F. Buckinx, O. Bruyère, J.-Y. Reginster We tested and validated irisin (IRI), myostatin (MYO), PIIINP, osteoglycin (OGN), TMEM119 (TMEM) and activin A (AA) and established the analytical performance, reference range and stability (considered unstable if more than 20% increase/decrease in the levels was observed in more than 10% of the samples). We were unable to obtain a valuable calibration curve with the Cusabio kits (TMEME and OGN). Coefficient of variation (CV) was too high for IRI (CV 17–30%), but were≤10% for the 3 other analytes. AA and MYO were stable up to 3months at –20°C and –80°C in serum or EDTA plasma and up to 6months at –80°C. PIIINP was stable only 1month in EDTA plasma (but not in serum) at –20°C or –80°C. After 3months of storage, PIIINP was not stable anymore, in serum or EDTA plasma, at –20°C or –80°C. Surprisingly, after 6months at –80°C, results returned in the±20% for both serum and EDTA plasma. PIIINP levels did not differ between men and women and the RR was (median, 90% CI) 1.2 (0.8–1.6)–6.0 (5.6–6.4)μg/L. The RR for MYO was 845 (437–1312)–6067 (5524–6552)pg/mL for men and 600 (268–1027)–4438 (4026–4837)pg/mL for women and the RR for AA was 177 (132–210)–622 (580–661)pg/mL for men and 98 (49–147)–480 (430–525)pg/mL for women. PIIINP and AA but not MYO acc...

Source: European Geriatric Medicine - December 15, 2015 Category: Geriatrics Source Type: research