PITUITARY RELEASE OF GROWTH-HORMONE AND PROLACTIN IN THE PRIMARY FIBROMYALGIA SYNDROME

Objective. Previously, we demonstrated hyperreactive adrenocorticotrop ic hormone (ACTH) release in patients with primary fibromyalgia syndro me (primary FMS). We investigated the pituitary release of growth horm one (GH) and prolactin (PRL) in search of further disturbances in neur oendocrine reactivity possibly associated with the pathophysiology of primary FMS. Methods. Ten female patients with primary FMS fulfilling the 1981 Yunus criteria and 10 matched, healthy and sedentary controls were subjected to an insulin induced hypoglycemia test; samples for m easurement of glucose, GH and PRL were taken at intervals. Results. Co mpared to the controls, the patients with primary FMS displayed signif icantly lower basal GH levels, whereas their basal PRL levels were sli ghtly, though significantly, higher (respectively p = 0.021 and p = 0. 041). Following hypoglycemia, there was a marked, statistically highly significant (p = 0.001), hyperreactivity of the GH response in patien ts with primary FMS. The PRL response showed wide interindividual Vari ation and did not differ between patients and controls. Conclusion. Ou r findings indicate that fibromyalgia, along with ACTH hyperreactivity , also exhibits a distinct disturbance in the GH-somatomedin C axis. W ith regard to PRL, the variation in individual responses limits conclu sions. The hyperreactive response patterns of GH and ACTH previously s uggest a common origin, which might be related to a subtle glucocortic oid deficiency.