Successful Improvement of Metabolic Disorders, Including Osteopenia, by a Dopamine Agonist in a Male Patient with Macro-Prolactinoma
Ayumu Takeno, Masahiro Yamamoto, Kyoko Okazaki, Toru Yamaguchi, Sugimoto Toshitsugu
(Internal Medicine 1, Shimane University Faculty of Medicine, Izumo, Sihmane, Japan)
Am J Case Rep 2016; 17:160-164
Bone metabolic disorders in patients with prolactinoma have not been fully characterized. The case presented herein illustrates potential causal associations between prolactinoma and osteopenia, with a reversal of the disorder by treatment with a dopamine agonist.
CASE REPORT: A 43-year-old male with macro-prolactinoma [PRL 7770 ng/mL] was referred to our hospital. He suffered was overweight [body mass index (BMI) 29.4 kg/m2] and had impaired glucose tolerance, hypertriglyceridemia, and osteopenia. The patient was administered cabergoline, a dopamine D2 receptor agonist, and the dose was gradually increased up to 9 mg/week over the period of 1 year. One year later, the patient’s serum PRL levels decreased to within the normal range (19.1 ng/mL), and his pituitary tumor mass decreased to 1/4 of its initial size. His weight, dyslipidemia, and impaired glucose tolerance improved within 1 year. A marked increase in the bone mineral density (BMD) at the second to fourth lumbar spine (from 0.801 g/cm2 to 0.870 g/cm2, +8.6%) and at the femoral neck (from 0.785 g/cm2 to 0.864 g/cm2, +10.1%) were observed despite the presence of unresolved hypogonadism.
CONCLUSIONS: Treatments with dopamine agonists represent a beneficial strategy for patients with prolactinoma accompanied with bone loss, in addition to their established efficacy in shrinkage of the size of pituitary tumors, normalization of PRL levels, and improvement of metabolic disorders.
Keywords: Dopamine Agonists - therapeutic use, Bone Diseases, Metabolic - etiology, Adult, Ergolines - therapeutic use, Glucose Intolerance - etiology, Humans, Hypertriglyceridemia - etiology, Male, Overweight - etiology, Pituitary Neoplasms - drug therapy, Prolactinoma - drug therapy