Acute Changes In Inflammatory Cytokines In Plasma And Peripheral Blood Mononuclear Cells Following Maximal Exercise With Nasal Breathing

Incorporating nasal breathing (NB) into exercise routines has gained popularity to enhance exercise performance and overall health. However, its potential effects on intracellular and extracellular inflammatory cytokines, crucial to the immune response, remain unclear. PURPOSE: This study examined the acute responses of pro- and anti-inflammatory cytokines in peripheral blood mononuclear cells (PBMCs - representing intracellular cytokines) and plasma (representing extracellular cytokines) following maximal exercise with NB. METHODS: Eleven physically healthy, sedentary men (age = 20.63 ± 1.36, BMI = 26.03 ± 3.16 kg/m2, and VO2max = 32.60 ± 6.46 mL/kg/min) were randomly assigned to either the NB (N = 6) or the combined (control) breathing (CB, N = 5) group. Both groups performed maximal exercise on a recumbent bike. Blood samples were collected in EDTA-containing vacutainer tubes before and immediately after maximal exercise to assess changes in pro- (IL-6 and IL-1β) and anti-inflammatory cytokines (IL-10) in plasma and PBMCs. PBMCs were isolated using density gradient centrifugation over Lymphoprep. RESULTS: The overall cytokine concentration was significantly lower in PBMCs than in plasma. For instance, the cytokine concentrations in PBMCs vs. plasma were as follows: IL-6 (1.92 ± 1.55 vs. 10.10 ± 9.3 pg/mL, p = 0.001), IL-10 (2.55 ± 1.41 vs. 18.18 ± 17.66 pg/mL, p = 0.008) and IL-1β (0.80 ± 0.82 vs. 17.73 ± 16.77 pg/mL, p = 0.004). No significant differences were observed in IL-10 and IL-1β between plasma and PBMC samples or between the NB and CB groups following maximal exercise. However, PBMC IL-6 was significantly lower (p = 0.029) in the NB (1.24 ± 1.27 pg/mL) than in the CB (2.79 ± 1.5 pg/mL) group. CONCLUSIONS: This study demonstrated that intracellular cytokine concentrations in PBMCs were lower than extracellular cytokine levels in plasma. This difference likely reflects the accumulation of secreted cytokines in plasma from multiple cellular and tissue sources, systemic pooling, and the transient nature of cytokines within PBMCs. Furthermore, the reduced levels of PBMC IL-1β following exercise with nasal breathing (NB) suggest potential immune health benefits. Further research is needed to confirm and expand upon these findings across different exercise modalities and diverse subject populations.