Wijayaratne Dilushi Rowena, Arambewela M H, Dalugama Chamara, Wijesundera Dishni, Somasundaram Noel, Katulanda Prasad
University Medical Unit, National Hospital of Sri Lanka, Colombo, Sri Lanka.
Diabetes and Endocrine Unit, National Hospital Sri Lanka, Colombo, Sri Lanka.
J Med Case Rep. 2015 Oct 30;9:241. doi: 10.1186/s13256-015-0736-z.
Acromegaly is an endocrine disorder arising from excessive serum growth hormone levels in adulthood and is characterized by progressive somatic enlargement. Biochemical confirmation is achieved by demonstration of elevated baseline serum growth hormone levels which are not suppressed during an oral glucose tolerance test, and by increased levels of serum insulin-like growth factor-1. The serum insulin-like growth factor-1 level provides an assessment of integrated growth hormone secretion and is recommended for diagnosis, monitoring, and screening of acromegaly. We report a case of a patient with acromegaly secondary to a pituitary microadenoma who presented with low insulin-like growth factor-1.
An 83-year-old Sinhalese woman presented to our hospital with an enlarging multinodular goiter. She was observed to have macroglossia, thickened coarse skin, acral enlargement, and newly detected, uncontrolled diabetes. A diagnosis of acromegaly was suspected. She did not complain of recent headaches, vomiting, visual difficulties, or galactorrhea and was clinically euthyroid. Her pulse rate was 84 beats/min, and her blood pressure was 150/90 mmHg. A visual field assessment did not reveal a defect. Her random growth hormone levels were 149 mU/L (<10 mU/L), and her oral glucose tolerance test was supportive of acromegaly with a paradoxical rise of growth hormone. Her serum age-specific insulin-like growth factor-1 level was below normal at 124.7 ng/ml (normal range 150-350 ng/ml). Her serum insulin-like growth factor-1 level, measured after glycemic control was achieved with metformin and insulin, was elevated, which is characteristic of acromegaly. Magnetic resonance imaging of her pituitary revealed a pituitary microadenoma. Acromegaly secondary to a growth hormone-secreting pituitary microadenoma was confirmed.
Systemic illnesses, including catabolic states, hepatic or renal failure, malnutrition, and diabetes mellitus, are known to decrease insulin-like growth factor-1 levels and may result in false-negative values in patients with acromegaly A low insulin-like growth factor-1 level does not exclude acromegaly in a patient with supportive clinical features and poorly controlled diabetes.
肢端肥大症是一种成年期因血清生长激素水平过高引起的内分泌疾病，其特征为身体进行性增大。生化确诊需证明基础血清生长激素水平升高且在口服葡萄糖耐量试验中未被抑制，以及血清胰岛素样生长因子-1水平升高。血清胰岛素样生长因子-1水平可评估生长激素的综合分泌情况，推荐用于肢端肥大症的诊断、监测和筛查。我们报告一例因垂体微腺瘤继发肢端肥大症且胰岛素样生长因子-1水平较低的患者。
一名83岁的僧伽罗族女性因多结节性甲状腺肿增大前来我院就诊。观察发现她有巨舌、皮肤粗糙增厚、肢端肥大，且新诊断出未控制的糖尿病。怀疑为肢端肥大症。她未诉近期头痛、呕吐、视力障碍或溢乳，临床甲状腺功能正常。她的脉搏率为84次/分钟，血压为150/90 mmHg。视野评估未发现缺损。她的随机生长激素水平为149 mU/L（<10 mU/L），口服葡萄糖耐量试验支持肢端肥大症诊断，生长激素呈反常升高。她的血清年龄特异性胰岛素样生长因子-1水平低于正常，为124.7 ng/ml（正常范围150 - 350 ng/ml）。在用二甲双胍和胰岛素控制血糖后测得的血清胰岛素样生长因子-1水平升高，这是肢端肥大症的特征。垂体磁共振成像显示垂体微腺瘤。确诊为生长激素分泌型垂体微腺瘤继发肢端肥大症。
已知包括分解代谢状态、肝或肾衰竭、营养不良和糖尿病在内的全身性疾病会降低胰岛素样生长因子-1水平，可能导致肢端肥大症患者出现假阴性值。对于具有支持性临床特征且糖尿病控制不佳的患者，低胰岛素样生长因子-1水平不能排除肢端肥大症。
