Several reports suggest that growth hormone (GH) deficiency may be a pathogenic factor in fibromyalgia syndrome (FM). This hypothesis has never been adequately examined.
We measured serum GH concentration after insulin induced hypoglycemia in subjects with FM. GH secretion in subjects with a maximal GH increase < 10 ng/ml after hypoglycemia was assessed by additional arginine stimulation.
In one of 56 subjects tested, GH remained below 3 ng/ml in both tests, satisfying the criteria for adult GH deficiency. Thirty-two subjects (67%) had a maximal GH > 10 ng/ml. We retrospectively found an inverse correlation between low density lipoprotein levels and maximal GH concentration in a subgroup of patients.
Severe GH deficiency is not a significant pathogenic factor in most patients with FM. We observed an impaired reactivity of the somatotropic axis in one-third of patients with FM, in keeping with a functional alteration of the hypothalamus.