Neuro-endocrine responses to excersice in fibromyalgia

Abstract EN

Objectives: Evaluation of the neuro-endocrine mechanisms namely hypothalamic-pituitary adrenal (HPA) axis as reflected by cortisol, and growth hormone-insulin like growth factor-1 axis (GH/IGF-1).

Also finding out the parameters of muscle function as reflected by creatine kinase and potassium to clarify their role in the pathogenesis of fibromyalgia (FM).

Lastly, investigating the effect of exercise on these neuro-endocrine mechanisms as well as on parameters of muscle function.

Subjects and Methods: Twenty female patients suffering of FM were enrolled in this study in addition to ten healthy age matched females.

All subjects including the controls performed a treadmill exercise for thirty minutes (acute exercise).

Laboratory parameters were performed for all subjects before and after exercise.

They included serum cortisol, serum GH, serum IGF-1, serum insulin like growth factor binding protein-1 (IGF-BP-1), creatine kinase (CK) and serum potassium (K).

Results: Highly significant differences were found as regards concentrations of cortisol, GH, IGF-1 and IGF-BP-1 between patients and controls before and after exercise p<0.001.

Furthermore, patients were classified according to the presence of clinical data (morning stiffness, vertigo, depression, anxiety, sleep disturbances, hearing loss and number of tender points).

Patients with positive clinical data showed highly significant differences as regards the various tested laboratory markers when compared to patients with negative clinical data.

Significant correlations were found between the tested laboratory markers in the patients’ group before and after exercise.

Stepwise multiple regression analysis was performed to choose the best parameters for diagnosis of FM in the basal condition (before exercise).

This revealed that IGF-1, IGF-BP-1 and CK enzyme were the best (F ratio=178.0, p<0.001).

Conclusion: FM syndrome involves multiple sites of dysregulation including the HPA axis and shows hyposecretion of GH, IGF-1 and IGF-BP-1.

The end organ (the muscle) in FM syndrome is also affected, as CK enzyme is abnormally low in response to exercise.

These results might help to understand the enigma of FM.

Moreover, in the light of our study we recommend further study using low doses of GH therapy together with regular exercise programs to help in the treatment of FM patients.