Chronic Stress and Cold

Data from two viral-challenge studies proposed that prolonged stress results in glucocorticoid receptor resistance (GCR) which is characterised by a decrease in the sensitivity of immune cells to glucocorticoid hormones that normally terminate the inflammatory responses.

In study 1, it was shown that in 276 volunteers stress effects were associated with GCR, with lymphocyte and neutrophil counts showing less sensitivity to circulation levels of cortisol. In turn, increased GCR resulted in a greater risk of developing a cold following exposure to rhinovirus.

Study 2 demonstrated that GCR can be predictive of the magnitude of inflammation in response to infection. Increased GCR interfered with the down-regulation of pro-inflammatory cytokine response subsequently increasing illness expression in individuals exposed to a cold virus.

The proposed model of the impact of chronic stress on the hypothalamic - pituitary - adrenal (HPA) regulation of the inflammatory cascade would have implications in a broader context as uncontrolled inflammation is a key factor in the  development and progression of many diseases.

References:
Cohen S, Janicki-Deverts D, Doyle WJ, et al. Chronic stress, glucocorticoid receptor resistance, inflammation, and disease risk. Proceedings of the National Academy of Sciences. 2012 Epub ahead of print.

Further details at: http://www.ncbi.nlm.nih.gov/pubmed/22474371