Residual effects of short-term whole-body cold-water immersion on the cytokine profile, white blood cell count, and blood markers of stress.

Background: One of the most challenging environmental extremes is immersion in cold/icy water, and consequent common assumption is that even a brief exposure to cold can lead to cold-related illnesses. The increase in the concentrations of the stress hormones cortisol, epinephrine (Epi), and norepinephrine (NE) in response to acute cold stress are thought to suppress the release of proinflammatory cytokines. No previous study has explored the residual consequences of whole-body short-term cold-water immersion (CWI; 14 °C for 10 min) on the immune response in healthy non-acclimated young adult men (aged 20-30 years).Materials and methods: In the current study, we tested the hypothesis that short-term acute whole-body CWI would induce high blood levels of cortisol, NE, and Epi, which in turn would increase circulating leukocyte numbers and delay the production of proinflammatory cytokines (tumor necrosis factor α (TNF-α), interleukin 1ß (IL-1ß), and IL-6). Results: Short-term whole-body CWI produced a stressful physiological reaction, as manifested by hyperventilation and increased muscle shivering, metabolic heat production, and heart rate. CWI also induced the marked release of the stress hormones Epi, NE, and cortisol. The change in IL-6 concentration after CWI was delayed and TNF-α production was decreased, but IL-1ß was not affected within 48 h after CWI. A delayed increase in neutrophil percentage and decrease in lymphocyte percentage occurred after CWI.Conclusion: These findings suggest that, even though CWI caused changes in stress and immune markers, the participants showed no predisposition to symptoms of the common cold within 48 h after CWI.

Recovering body temperature from acute cold stress is associated with delayed proinflammatory cytokine production in vivo.

A poor outcome of whole-body hypothermia often results from a late complication, rather than from acute effects of hypothermia. A low body (cell) temperature or the increase in the concentrations of the stress hormones cortisol, epinephrine, and norepinephrine in response to acute cold stress have been proposed as potent proinflammatory cytokine suppressant. In the current study, we tested the hypothesis that the recovery of body temperature from a whole-body intermittent cold-water immersion (CWI, at 13-14 °C for a total 170 min) is associated with a delayed response of proinflammatory cytokines in young healthy men. Our results revealed a delay in the increase in the proinflammatory interleukin 6 and interleukin 1ß cytokines after the CWI, which paralleled the changes in cortisol, epinephrine, norepinephrine, and body temperature. CWI decreased tumor necrosis factor α (TNF-α) immediately and 1 h after the CWI. Although TNF-α had recovered to the pre-immersion level at 2 h after CWI, its natural circadian cycle kinetics was disrupted until 12 h after the CWI. Furthermore, we showed that CWI strongly modified the white blood cell counts, with changes reaching a peak between 1 and 2 h after the CWI.