Systemic effects of platelet-rich plasma local injection on serum and urinary anabolic metabolites: A prospective randomized study.

Platelet-rich plasma (PRP) is widely utilized in the treatment of sports injuries. However, potential systemic effects after localized PRP injection are unclear at present. In this prospective randomized study, 24 Taiwanese male athletes with tendinopathy were randomized into a PRP group (n = 13) or a saline group (n = 11). The concentrations of serum and urine biomarkers were quantified by enzyme-linked immunosorbent assay assessment as well as gas chromatographic and mass spectrometric analysis, respectively. The results showed no significant differences in serum levels of growth hormone, insulin-like growth factor-1, insulin-like growth factor-binding protein 3, vascular endothelial growth factor, platelet-derived growth factor-BB, or serum substance P(SP) between the two groups before intervention, nor at 1, 2, or 7 days after intervention. However, a significant decrease in the serum SP level 1 and 7 days after PRP injection was observed. Regarding urinary concentrations of metabolites of anabolic androgenic steroids (AAS), no between-group differences before intervention, nor at 1, 2, or 7 days after intervention, were observed. Our study failed to observe significant surge of serum anabolic molecules and urinary excretion of anabolic AAS metabolites after PRP injection.