Colao Annamaria, Pivonello Rosario, Cavallo Luigi M, Gaccione Maria, Auriemma Renata S, Esposito Felice, Cappabianca Paolo, Lombardi Gaetano
Department of Molecular and Clinical Endocrinology and Oncology, Section of Endocrinology, University Federico II of Naples, Naples, Italy.
Clin Endocrinol (Oxf). 2006 Aug;65(2):250-6. doi: 10.1111/j.1365-2265.2006.02584.x.
This analytical, retrospective study was designed to select cut-off thresholds of mean GH levels during a diurnal profile and nadir GH levels after oral glucose tolerance test (OGTT) according to age to diagnose surgical remission of acromegaly.
One hundred forty-one patients (76 women, aged 44 +/- 15 years and 65 men, aged 43 +/- 13 years) were included in this study. For the purpose of this study, remission was based on insulin-like growth factor-I (IGF-I) levels in the normal range for age. Diagnostic accuracy was analysed by receiving-operator characteristics (ROC) curves in the entire series, and in young (20-40 years), middle-aged (41-60 years) and older patients (> 60 years), separately.
Sixty patients (42.6%) had normal IGF-I levels after surgery. In the entire series, in young and in middle-aged patients, the ROC analysis showed that optimum cut-off for mean GH levels was 2.3 microg/l (diagnostic accuracy range, 94-97%) whereas that for nadir GH after OGTT were, respectively, 0.85, 0.9 and 0.8 microg/l (diagnostic accuracy range, 90-95%). In the older patients, the optimum cut-off selected for mean GH levels was 1.4 microg/l and that for nadir GH after OGTT was 0.5 microg/l (diagnostic accuracy, 100% for both). The comparative analysis of the ROC curves did not show any significant difference between mean GH and nadir GH after OGTT (P = 0.21).
The criteria currently accepted for diagnosing post-surgical remission of acromegaly have high diagnostic accuracy only in the patients aged below 60 years. In older patients, lower cut-offs (i.e. = 1.4 microg/l for fasting GH and = 0.5 microg/l for nadir GH after OGTT) predict normal IGF-I levels. Mean GH levels during a diurnal profile have similar diagnostic accuracy of nadir GH levels after OGTT. This suggests that OGTT is not necessary to establish surgical cure.
本分析性回顾性研究旨在根据年龄选择昼夜生长激素（GH）水平曲线的平均GH水平及口服葡萄糖耐量试验（OGTT）后GH最低点水平的截断阈值，以诊断肢端肥大症手术缓解情况。
本研究纳入了141例患者（76例女性，年龄44±15岁；65例男性，年龄43±13岁）。本研究中，缓解基于年龄对应的胰岛素样生长因子-I（IGF-I）水平在正常范围内。通过受试者工作特征（ROC）曲线分析整个队列以及分别在年轻（20 - 40岁）、中年（41 - 60岁）和老年患者（>60岁）中的诊断准确性。
60例患者（42.6%）术后IGF-I水平正常。在整个队列、年轻和中年患者中，ROC分析显示，昼夜GH平均水平的最佳截断值为2.3μg/L（诊断准确性范围为94 - 97%），而OGTT后GH最低点水平分别为0.85、0.9和0.8μg/L（诊断准确性范围为90 - 95%）。在老年患者中，昼夜GH平均水平的最佳截断值为1.4μg/L，OGTT后GH最低点水平为0.5μg/L（两者诊断准确性均为100%）。ROC曲线的比较分析显示，OGTT后GH平均水平与最低点水平之间无显著差异（P = 0.21）。
目前用于诊断肢端肥大症术后缓解的标准仅在60岁以下患者中具有较高的诊断准确性。在老年患者中，较低的截断值（即空腹GH = 1.4μg/L，OGTT后GH最低点 = 0.5μg/L）可预测IGF-I水平正常。昼夜GH平均水平与OGTT后GH最低点水平具有相似的诊断准确性。这表明OGTT对于确定手术治愈并非必要。
