Endocrine Abstracts

Introduction: Acromegaly with normal IGF-1level is rarely diagnosed and is difficult to recognize. In acromegalic pa-tients with poorly controlled diabetes, malnutrition, hepatic injury, hepatic congestion due to heart fail-ure, inflammatory diseases, renal dysfunction, and malignant neoplasm, IGF-1 synthesis is inhibited and thus in such cases normal IGF-1 levels may be observed. The aim of the study is to present a rare case of a patient with acromegaly and normal IGF-1 level, and to emphasize that low or normal concentrations of IGF-1 do not rule out the diagnosis of acromegaly.

Case report: A 75-year-old woman with pituitary macroadenoma was admitted to hospital with suspected acromegaly. The pituitary tumor was visualized 24 years earlier during CT performed because of headaches. 1 year later, without hormonal evaluation, the patient was disqualified from the neurosurgical treatment. For 23 years she had performed only periodic imaging controls. In 2012 CT revealed a focal lesion 17×15 mm within the Turkish saddle, suggesting the presence of craniopharyngioma. 28 years ago the patient had undergone partial thyreoidectomy due to nodular goiter. She also suffered from long-term arterial hypertension resistant to treatment, chronic heart failure, atrial fibrillation with ventricular extrasystolia and severe osteoarticular disorders. She had thickened facial features, enlarged tongue, hands and feet, and increased sweating. Basal GH level was 10.37 ng/ml (n:0.03–2.47) without GH suppression during OGTT (3.79 ng/ml, n:<0.4), IGF-1=157.3 ng/ml (n: 29–204). The remaining pituitary functions were normal. On the basis of OGTT [96 mg%–150 mg%] an impaired glucose tolerance was diagnosed. In MRI pituitary tumor 17×19×14 mm was detected. Renal insufficiency, malnutrition [BMI=34.2 kg/m²] or malignant neoplasms were excluded. Acromegaly was diagnosed and Lanreotyd Autogel 120 mg every 28 days was introduced. Because the patient refused neurosurgery, she remains on long-acting somatostatin analogue therapy.

Conclusion: Probably the low concentration of IGF-1 in the presented case was caused by liver damage secondary to long-term severe congestive heart failure, most likely caused by long-term untreated acromegaly and hyperglycemia.