Longitudinal Biomarker Changes in Athletes

Whole blood was collected (1) prior to non-contact conditioning (baseline); (2) at weeks 8, 12, 17, 21, 26, and 33 (Figure 1B). Blood draws during the regular season [Weeks 12, 17, 21, and 26 (end of season)] were done on Tuesday or Wednesday following game day. Week 33 was 7 weeks after the end of treatment. Twelve-hour fasted blood samples (22 ml whole blood) were collected via venipuncture into three vacutainer tubes [1 × 4.5 ml tri-sodium citrate, 1 × 7.5 ml powdered glass clot activator, 1 × 10 ml ethylene diamine tetra-acetic acid (EDTA)]. The tri-sodium citrate tube was stored on ice, packaged, and sent for analysis. Samples in the EDTA tube were centrifuged within 2 min of collection (1,714 g for 15 min). Samples in the clot activator tube were centrifuged 30 min post-collect (1,714 g for 15 min). Aliquots of red blood cells and plasma (EDTA tube) and serum (clot activator tube) were stored at−80C until analyzed. Serum neurofilament light (NfL) was quantified at baseline, Week 17, and Week 26 from serum using the NF-Light Simoa Assay Advantage Kit (Quanterix Corp, Billerica, MA). Other blood-based biomarkers included plasma fatty acids, interleukin-6 and tumor necrosis factor-alpha, all of which are thoroughly described in Mulllins et al. (43 (link)). For treatment effects in the present analyses, DHA and EPA data are also reported here.