Can cortisol levels predict the severity of acute whiplash-associated disorders?

BACKGROUND: The exact underlying mechanism of whiplash-associated disorders still remains obscure. Central sensitization of the brain to painful stimulus and disturbances in the hypothalamic-pituitary-adrenal axis has been suggested to contribute to the development of whiplash-associated disorders. Although cortisol is a well-known factor in the acute stress response and its effects on chronic pain sensation were studied, information is lacking regarding the relation between acute phase cortisol concentrations and the intensity of whiplash-associated disorders. The aim of this prospective observational study was to investigate the relationship between acute serum cortisol concentrations and the severity of whiplash-associated disorders.

METHODS: 55 patients enrolled in the study and they answered a pertinent questionnaire. A blood sample was drawn to determine serum cortisol concentration.

RESULTS: The mean cortisol concentration of the whiplash-associated disorder score 2-3 patients was significantly lower compared to the whiplash-associated disorder score 1 patients, 9.5 ± 6.9 vs. 13.22 ± 8.3 µg% (p = 0.02). The mean cortisol concentrations increased significantly from mild through moderate to serious grade of severity of accident as perceived by the patient, 9.64 ± 4.82, 11.59 ± 6.85, 17.39 ± 12.1 µg% (p = 0.02).

CONCLUSIONS: The study supports the possibility that cortisol plays a role in the development of whiplash-associated disorders. Low or relatively low cortisol concentrations might be associated with more severe forms of the disorder.