Effectiveness of Metformin Treatment in the Teenager with Maturity-Onset Diabetes of the Young Type 3 and Oligomenorrhoea: A Case Presentation

Abstract

Sulphonyloureas are a treatment of choice for Maturity-Onset Diabetes of the Young type 3 (MODY3) young patients with excellent results, although they should be used with a great caution. In adult MODY3 patients hypersensitive response to sulphonyloureas and a decreased response to metformin in compare to sulphonyloureas were reported. A case of teenager with MODY 3 and oligomenorhoea, successfully treated with metformin is presented. A fifteen and a half year-old girl was diagnosed with oligomenorrhoea. Due to detected glucosuria and blood glucose (BG) at 267 mg/dl she was referred to a pediatric endocrinologist. She did not present with typical diabetes mellitus (DM) symptoms, however she had a three generations family history positive for insulin-dependent DM. She presented with a good clinical condition. The underweight (Body mass index 18.7 kg/m2) and discrete hirsutism were observed. Glucosuria, ketonuria, BG above 200 mg/dl in 24‑h BG profile, and HbA1c 7.1% confirmed the diagnosis of DM, and insulinotherapy was initiated. Further diagnostics revealed high C-peptide levels and negative diabetes autoantibodies. Due to a low requirement of insulin and a presence of oligomenhorea, insulinotherapy was replaced with metformin. Three months after metformin introduction, HbA1c level normalized and menstruation cycles became regular. Genetic tests confirmed the diagnosis of MODY3 in the patient and her family. No pathology in the morphology and function of the kidneys was found. Due to the positive effect of metformin on regulation of menstrual cycles, and the continued high C-peptide level, the treatment with metformin has been continued. During the last three years follow-up, HbA1c levels fluctuated between 5.6-5.8% and menstrual cycles have been regular. Our case presents that metformin could be an adequate treatment for teenagers with MODY 3 and oligomenorhea/ PCOS with good results of diabetes control and benefits for ovarian function.