A Controlled Study on Serum Insulin - Like Growith Factor 1 (Somatomedin C) Levels in Fibromyalgia

Yoo, Byung Hoon; Kang, Jeong Kweon; Oh, Wan Soo; Yon, Jun Heum; Kim, Jeong Won; Hong, Kee hyek; Song, Chan Woo

Abstract

BACKGROUND: Fibromyalgia is a common syndrome of musculoskeletal pain and fatigue. Lacking distinctive histological or laboratory abnormality in diagnosis, it has often been considered a form of "psychogenic rheumatism. Fibromyalgia causes much distress to the affected patients and often frustrates physicians, who are unable to start rational therapy on any logical disease pathology.
METHODS
Growth hormone is essential for muscular homeostasis. In the present study, the notion that the stage-4 sleep anomaly typically seen in the fibromyalgia syndrome may disrupt growth hormone secretion was tested. Because growth hormone has a very short half-life, serum levels of somatomedin C were measured; somatomedin C is the major mediator of growth hormones anabolic actions and is a prerequisite for normal muscle homeostasis. Serum levels of somatomedin C using acid-extraction procedure and two-site immunoradiome-tric assay (IRMA) and number of tender points were measured in 27 female patients with fibromyalgia from 40 to 60 years old and 27 healthy controls.
RESULTS
There were no differences in the concentration of somatomedin C between fibromyalgia patients and controls (mean+/-SD: 178.3+/-75.5 ng/ml versus 166.3+/-76.6 ng/ml; p=0.55). And there were no correlations between number of tender point and serum somatomedin C level by linear regression analysis.
CONCLUSIONS
These findings did not support that there is a distinctive disruption of the growth hormone-somatomedin C neuroendocrine axis in a fibromyalgia syndrome. But we can not discard the hypothesis that disturbed sleep predispose to muscle pain.