Pro- and anti-inflammatory cytokine balance in strenuous exercise in humans.
Level 4 - case-series / case-control
Single-arm prospective before-and-after time-course study without a non-exercise control group.
PubMed 9925898 · doi:10.1111/j.1469-7793.1999.287ad.x
What was done
Ten male runners (median age 27.5 years, range 24-37; median marathon completion time 3 hours 26 minutes) provided blood samples before, immediately after, and every 30 minutes for a 4-hour recovery period after the 1997 Copenhagen Marathon. Plasma concentrations of TNF-alpha, IL-1beta, IL-6, IL-1ra, sTNF-r1, sTNF-r2, and IL-10 were measured by ELISA.
What was found
Plasma IL-6 peaked immediately post-race with a 128-fold increase over pre-exercise levels. Plasma IL-10 also peaked immediately post-exercise with a 27-fold increase. IL-1ra peaked at 1 hour post-exercise with a 39-fold increase. Plasma levels of IL-1beta, TNF-alpha, sTNF-r1, and sTNF-r2 peaked within the first hour of recovery, showing 2.1-fold, 2.3-fold, 2.7-fold, and 1.6-fold increases, respectively.
Why it matters
This study outlines the time course of cytokine responses to prolonged exhaustive exercise, demonstrating that large increases in inflammatory-responsive IL-6 are countered by rapid surges in anti-inflammatory IL-10 and cytokine inhibitors.
Limits
The sample size is very small (n=10) and entirely composed of young to early-middle-aged males, limiting generalizability to women, older adults, or clinical cohorts. There was no non-exercising control group, and observations ended after 4 hours of recovery.
Cited by
- supports Exercise stimulates the production of anti-inflammatory cytokines.