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 never been adequately examined.
METHODS: 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.
RESULTS: 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.
CONCLUSION: 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.