Endocrine Abstracts

Introduction: Hypothalamic obesity is defined as a syndrome of intractable weight gain as a result of hypothalamic lesions. Craniopharyngioma is responsible for more than half of the cases of hypothalamic obesity, but other pathologies can be implied. The syndrome can occur due to the tumour itself or its treatment (surgery or radiotherapy). Metformin is an antidiabetic drug that has also been used to treat nondiabetic obese patients, as it has been demonstrated to promote weight loss. Metformin alone has not been previously tested in patients with hypothalamic obesity.

Case presentation: We present the case of two patients with hypothalamic obesity, which were efficiently treated with metformin. The first case is a 44-year-old woman who has gained 45 kg following surgery for cranyopharyngioma, despite caloric restriction and treatment with sibutramine and then orlistat. When she reached 150 kg, treatment with Metformin was initiated. During treatment she lost 34 kg in 30 months and her insulin resistance decreased significantly. The second case is a patient who was diagnosed at 6.4 years with a suprasellar mixed germ cell tumour (immature teratoma and germinoma). She underwent surgery, radiotherapy and chemotherapy. Following surgery, she developed severe hypothalamic obesity with insatiable bulimia, gaining dramatically 32 kg in 2.5 years. As complication of this major weight gain she had severe insulin resistance, dyslipidaemia, and steatohepatitis. As nutritional intervention and treatment with sibutramine and orlistat failed, treatment with metformin was initiated. After 1 year she lost 21 kg, her lipid profile and insulinaemia improved considerably and her liver enzymes normalised.

Conclusion: Metformin proved to be an efficient and well tolerated treatment in these two patients with hypothalamic obesity, showing that it can be an option in these dramatic cases.