Endocrine Abstracts

Introduction: Alterations in glucose homeostasis and diabetes mellitus (DM) are the most common metabolic comorbidities in acromegaly. DM has been reported in 16–56% of patients with acromegaly. It is estimated that 20% of patients with acromegaly have developed DM before the formal diagnosis of acromegaly. We report a case of a patient with acromegaly secondary to a pituitary macroadenoma who presented with diabetes.

Case report: A 47- year-old female patient was admitted to our internal medicine clinic for control and assessment of diabetes before tooth extraction due to dental caries. She had suffered from type 2 diabetes for ten years. She had been unable to control the blood glucose level adequately, 1- year history of amenorrhea, generalized fatigue and weight loss for the last one year. She had been on oral antidiabetic therapy (metformin, dapagliflozin, gliclazide, and sitagliptin) for one year with bad glucose values. On examination, her vital signs were within normal. Physical examination revealed acromegalic coarsened facial features but she had no clear-cut cushingoid features and acral enlargement. Anthropometry and laboratory tests were as follows: Height, 150 cm; body weight 55 kg; body mass index (BMI), 24.44 kg/m² basal and postprandial glycemia 202, and 280 mg/dL respectively, A1c level of 11.8%. Investigations revealed high IGF-1 levels of 735 mg/l (101–267 mg/l) and growth hormone nadir (1 hour after a 75-g oral glucose load) was 30 ng/mL (<1 ng/mL). Complete pituitary hormonal profile revealed prolactin 28.29 ng/mL (4–25 ng/mL), thyroid-stimulating hormone 1.02 uIU/mL (0.35–4.94 uIU/mL), FT3 2.81 pg/mL (2.3–4.2 pg/mL), FT4 1.25 ng/dL (0.89–1.76 ng/dL), follicle-stimulating hormone 57.78 mIU/mL (3.35-21.63 mIU/mL), luteinizing hormone 15.94 mIU/mL (2.39-6.6 mIU/mL), adrenocorticotropic hormone 26.7 pg/mL (7.2-63.3 pg/mL) and cortisol 22.71 mg/dl (5.27-22.45 mg/dl). Magnetic resonance imaging of the sella demonstrated a 17x14 mm pituitary adenoma. The patient was diagnosed with acromegaly, and acromegaly-associated exacerbation of diabetes mellitus. Trans-sphenoidal resection was performed and histopathologic and immunohistochemical findings indicated GH and PRL -producing pituitary adenoma.

Discussion: Acromegaly is often develop insidiously and diagnosis may be delayed as a consequence. The present report outlines a case of missed diagnosis of acromegaly associated with severe hyperglycemia. Clinical suspicion of acromegaly is generally difficult during anamnesis of patients with DM, particularly in the absence of disease-related symptomatology. When treating patients diagnosed with diabetes, secondary causes should not be neglected.