Demographic, anthropometric and intrasubject variations affect platelet-rich plasma formulation

Abstract

Purpose: The purpose of this study is to describe the inter- and intra-individual differences in the platelet concentration between blood and platelet-rich plasma (PRP) preparation, assess intersubject differences considering demographic and anthropometric variables, describe PRP code distribution and analyse intrasubject variability. Methods: A retrospective analysis was conducted using a single-centre patient database from November 2021 to November 2023. It included patients with musculoskeletal pathologies treated with PRP injections. Primary variables were demographic characteristics (sex, age, body mass index [BMI]) and platelet concentrations in blood and PRP during treatments. Secondary analysis focused on PRP code frequency distribution and intrasubject variability according to different coding systems. Results: Here, 686 patients met the inclusion criteria. PRP exhibited significantly higher platelet concentrations compared to blood (378.01 ± 136.25 × 103 platelets/µL vs. 221.97 ± 58.21 × 103 platelets/µL, p < 0.001). Younger patients had higher platelet concentrations in both blood (p = 0.004) and PRP (p = 0.003), whereas female patients showed higher platelet concentrations only in blood (p < 0.001). The platelet concentration ratio was higher in males (p < 0.001) and those with higher BMI (p = 0.023). Significant differences were found between the existing and modified PRP coding systems (p < 0.001). Intrasubject variability was higher in PRP than in blood (coefficient of variance: 21.32 ± 17.36 in blood vs. 27.85 ± 19.10 in PRP, p < 0.001). Conclusion: Age, gender, BMI and intrasubject variations significantly affect PRP formulation, emphasizing the importance of addressing these variables for a more predictable, personalized and effective therapeutic approach. Level of Evidence: This is a retrospective study. Level IV.