European Journal of Psychotraumatology (Sep 2012)
The hypothalamus–pituitary–adrenal axis in patients with CRPS type 1: molar cortisol to DHEA ratio increases with disease duration
Abstract
Background : The main complaint symptom of complex regional pain syndrome type 1 (CRPS-1) is neuropathic pain. There is significant co-morbidity between neuropathic pain and neuropsychiatric disorders, including anxiety and depression. A decrease in dehydroepiandrosterone (DHEA) or increase in the molar cortisol to DHEA ratio (molar F/D ratio) is commonly found in patients with psychiatric disorders, such as major depression and posttraumatic stress disorder. However, no information about DHEA secretion is available for patients with CRPS-1. The present study determined the molar F/D ratio within the first hour after awakening in patients with CRPS-1 undergoing combined antidepressant treatment with analgesics and non-steroidal anti-inflammatory drugs. Method : To do this, cortisol and DHEA concentrations were determined from saliva samples, which were collected immediately upon awakening, 30 and 60 min after awakening and at nighttime from patients with CRPS-1 (n=26) and age-matched healthy subjects (n=25). The beck depression inventory (BDI) was used to quantify depression levels in the medicated patients. The net increase in cortisol levels within the first hour after awakening (CARi) and the area under the cortisol curve with respect to ground within the first hour after awakening (CARauc) were calculated and used as an index of cortisol secretion. The area under the DHEA curve with respect to ground within the first hour after awakening (DHEAauc) was used as an index of DHEA secretion. Results : The mean BDI scores of patients were 19.0±9.0 (range, 5–41). The BDI scores were not associated with any parameters for cortisol, DHEA secretion or other disease-related parameters such as disease duration, frequency of spontaneous pain, or extension of disease spread. We did not observe a difference in indices for cortisol and DHEA secretion between patients who had a value higher than the cut-off for chronic pain (BDI score 21, n=10) or patients who had lower than cut off BDI scores (n=16). Among indices for cortisol and DHEA secretion, the molar CARauc to DHEAauc (molar F/Dauc) ratio was associated with disease duration. Patients who suffered from disease for relatively longer time (subgroup 4 month ≤ ) had a higher molar F/Dauc ratio than both controls and patients who suffered for a relatively shorter time (subgroup 4 month ≥ ). There was no difference in BDI scores between subgroups. Conclusion : We used combined analgesic treatment with tricyclic antidepressants, anticonvulsants and non-steroidal anti-inflammatory drugs to relieve pain and pain-related symptoms, such as depression, in patients with CRPS-1, but these results indicate that DHEA secretion after the awakening period decreases in the combined treatment condition.
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