Cortisol awakening response and pain-related fear-avoidance versus endurance in patients six months after lumbar disc surgery.

Recent research indicates that stress-induced, prolonged deviations in basal adrenocortical activity might contribute to ongoing/recurrent pain following lumbar disc surgery. Further, fear-avoidance and endurance responses to pain (FAR and ER) are regarded as important risk factors for pain after surgery. In patients with non-specific low back pain, FAR appear to possibly increase pain-related arousal, whereas ER may have an arousal-lowering effect, indicated by adrenocortical activity. The current study explores the relationship between basal adrenocortical activity and FAR and ER. Thirty-six patients 6 months after lumbar disc surgery participated. Basal adrenocortical activity was assessed through the cortisol awakening response (CAR), using salivary samples collected on two consecutive days. FAR and ER were estimated using questionnaires. While the ER variables pain-persistence behavior and positive mood despite pain showed negative associations with the CAR, the FAR variables fear-avoidance beliefs and avoidance of social activity were positively correlated with it. Additionally, higher CAR levels were found in patients with high versus patients with low fear-avoidance beliefs and, conversely, in patients with low versus high positive mood and pain persistence. These results indicate that FAR may increase the individuals' level of pain-related stress among patients after disc surgery, while ER may lower it.