Type 2 diabetes mellitus: An unusual association with Down's syndrome
A 28-year-old male patient with a body mass index (BMI) of 25.1 kg/m2 and positive family history of DM reported to the out-patient clinic of the department of Endocrinology, Medwin hospital with the clinical features of polyuria and polydipsia for last 1 year. There was no history of weight loss or any significant past medical history. Physical examination revealed typical mongolian facies and other features of DS such as short stature (145 cm), brachycephaly, short neck and pot belly, small mouth with protruding tongue, wide occipital region and characteristic small eyes of DS. Thyroid was not palpable. Laboratory data revealed diabetes with fasting plasma glucose of 256 mg/dl, postprandial plasma glucose of 375 mg/dl and glycated hemoglobin (HbA1C) level of 9.9%. Urine was negative for ketone bodies. C-peptide assay showed fairly well-preserved pancreatic β cell function: Fasting values of 1.3 pmol and stimulated values of 2.4 pmol/ml (normal values in non-diabetic subjects, fasting >1.5 pmol/ml and stimulated >4.0 pmol/ml). Glutamic acid decarboxylase (GAD) antibody testing (3.2 IU/ml) was negative. These values were suggestive of type 2 DM. He also had primary hypothyroidism with a thyroid stimulating hormone level of 54 mIU/l and T4 value of 3.5 μg/dl. Other investigations (hemogram, renal and liver function parameters, serum electrolytes and lipid profile) were within the normal limits. He was initiated on basal glargine insulin at a dose of 15 units subcutaneously at night along with oral hypoglycemic agent (glimepiride 2 mg/metformin 1000 mg) once daily and L-thyroxine 100 μg daily. Later, the doses of insulin were reduced and subsequently withdrawn completely and he is maintained well on oral hypoglycemic agents alone.