# Blood flow restriction training before platelet‐rich plasma preparation induces a significant reduction in its interleukin‐6 levels: A pilot randomised controlled trial

## TL;DR

This study shows that blood flow restriction training before preparing platelet-rich plasma significantly lowers interleukin-6 levels, which could improve treatments for musculoskeletal injuries.

## Contribution

The study demonstrates that BFR training reduces IL-6 in PRP, offering a novel approach to optimize PRP for injury treatment.

## Key findings

- BFR training increased platelet concentration and dose at T2 and T3.
- Leucocyte concentrations and dose decreased significantly at T2 in the BFR group.
- IL-6 concentrations were significantly lower in the BFR group at all time points.

## Abstract

To assess platelet‐rich plasma (PRP) changes in platelet and leucocyte count, insulin‐like growth factor (IGF‐1) and interleukin 6 (IL‐6) concentration after bilateral low‐load knee extensions with blood flow restriction (BFR).

A randomised controlled trial involving two groups was conducted. The intervention group underwent low‐load bilateral knee extensions with BFR, while the control group without BFR. Inclusion criteria were (1) male individuals, (2) between 18 and 40 years, (3) with Tegner activity level ≥5 and (4) no musculoskeletal conditions that would interfere with exercise. The participant performed a standard protocol of 30–15–15–15 repetitions of consecutive sets with 30‐s rest intervals at 80% of limb occlusive pressure and a 15‐lb load. PRP platelet and leucocyte count, IGF‐1 and IL‐6 concentration measurements (via flow cytometry, chemiluminescence testing and immunochromatography, respectively) were conducted before exercise and 10, 20 and 30 min after the intervention (T1, T2, T3 and T4, respectively).

A total of 24 participants were enrolled and allocated into two groups. The exercise bout in the BFR group resulted in higher platelet concentration and dose at T2 and T3, reaching a mean 9.9% maximum concentration increase and a mean 15.6% maximum dose increase at T2 (p = 0.07). Similarly, leucocyte concentrations and dose presented a steep decrease at T2, representing a 17.8% and 16.8% decrease, respectively. Moreover, a peak increase in IGF‐1 concentration of 4.1% above baseline was observed at T3. IL‐6 concentrations were significantly lower at all time points in the BFR group (˂1 pg/mL, p = 0.01).

Low‐load bilateral knee extensions with BFR induced a significant reduction of IL‐6 concentration in PRP, which holds potential to tailor treatment for specific musculoskeletal injuries.

Level I.