关键词: 垂体瘤, 肝硬化, 葡萄糖生长激素抑制试验

Abstract:

The oral glucose growth hormone suppression test is commonly used in the clinical diagnosis of acromegaly, but its results can be influenced by a variety of factors. This case report discusses a patient with a pituitary tumor and concurrent liver cirrhosis, highlighting the complexities in interpreting test results under such conditions. The patient, a 54-year-old male, presented with blurred vision as his primary complaint. Notably, the physical examination revealed no changes in facial features, no enlargement of hands or feet, and no other symptoms typically associated with acromegaly, which might otherwise suggest excessive growth hormone activity. Magnetic Resonance Imaging (MRI) of the pituitary gland indicated that the gland was within normal size parameters, but a small low-intensity lesion mea-suring approximately 3 mm×2 mm identified. This finding was consistent with a pituitary microadenoma. The patient's fasting growth hormone levels were significantly elevated at 8.470 μg/L, compared with the normal range of less than 2.47 μg/L. Conversely, fasting insulin-like growth factor-1 (IGF-1) levels were notably low, recorded at 41 and 52 μg/L, whereas the normal range for a person of his age was between 87 and 234 μg/L. Other pituitary hormones, including those regulating the thyroid, adrenal cortex, and sex hormones, were found to be within normal ranges. Despite this, during the glucose growth hormone suppression test, an abnormal elevation of growth hormone was observed. To investigate further, the patient was administered branched-chain amino acids, and the suppression test was repeated. However, the abnormal elevation of growth hormone persisted, indicating a failure to normalize the response. Given the patient's lack of clinical signs typically associated with elevated growth hormone secretion, the history of liver cirrhosis became a significant consideration. The disparity between elevated growth hormone levels and reduced IGF-1 levels suggested that the pituitary lesion was a non-functional adenoma rather than a source of excess hormone production. Consequently, it was concluded that the abnormal response of growth hormone to the glucose suppression test was likely related to the patient's liver cirrhosis. In addition to chronic liver disease, various other conditions could influence the results of the oral glucose tolerance growth hormone suppression test. According to the literature, factors such as puberty, diabetes, anorexia nervosa, and protein malnutrition could also affect test outcomes. These conditions could cause similar abnormalities in growth hormone dynamics, complicating the diagnosis. Therefore, clinicians must be vigilant and consider these potential influences when interpreting test results.For an accurate diagnosis of acromegaly, it is essential to combine clinical symptoms, detailed medical history, and imaging studies. The presence of conditions like liver cirrhosis should prompt careful interpretation of the test results, ensuring that other contributing factors are not overlooked. This comprehensive approach is crucial to avoid misdiagnosis and to ensure that appropriate treatment strategies are implemented based on a thorough understanding of the patient's overall health status.

Key words: Pituitary neoplasms, Liver cirrhosis, Glucose tolerance test