Stringent endocrinological testing reveals subnormal growth hormone secretion in some patients with fibromyalgia syndrome but rarely severe growth hormone deficiency

Objective. Several reports suggest that growth hormone (GH) deficiency may be a pathogenic factor in fibromyalgia syndrome (FM). This hypothesis has n ever been adequately examined. Methods. We measured serum GH concentration after insulin induced hypoglyce mia in subjects with FM. GH secretion in subjects with a maximal GH increas e < 10 ng/ml after hypoglycemia was assessed by additional arginine stimula tion. Results. In one of 56 subjects tested, GH remained below 3 ng/ml in both te sts, satisfying the criteria for adult GH deficiency. Thirty-two subjects ( 67%) had a maximal GH > 10 ng/ml. We retrospectively found an inverse corre lation between low density lipoprotein levels and maximal GH concentration in a subgroup of patients. Conclusion. Severe GH deficiency is not a significant pathogenic factor in most patients with FM. We observed an impaired reactivity of the somatotrop ic axis in one-third of patients with FM, in keeping with a functional alte ration of the hypothalamus.