Bancos Irina, Algeciras-Schimnich Alicia, Grebe Stefan K, Donato Leslie J, Nippoldt Todd B, Erickson Dana
Division of Endocrinology, Metabolism and Nutrition, Department of Medicine, Mayo Clinic, Rochester, Minnesota.
Division of Clinical Biochemistry and Immunology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota.
Endocr Pract. 2014 May;20(5):421-6. doi: 10.4158/EP13359.OR.
Our aim was to identify the frequency and possible clinical and analytical factors leading to "falsely" elevated insulin-like growth factor-1 (IGF-1).
We performed a retrospective review of patients with IGF-1 concentrations above the reference interval. They were selected from a database of patients who had consecutive IGF-1 measurements between the years 2007-2010.
Out of 2,747 unique patients, 117 (4%) were found to have IGF-1 concentrations above the reference interval that were considered false-positives following a review of the clinical data. There was no relationship between the percentage of increase in IGF-1 and age, sex, body mass index (BMI), comorbidities, medication use, gonadal status, baseline growth hormone (GH), or insulin-like growth factor binding protein-3 (IGFBP-3) concentrations. An abnormal IGF-1 concentration led to performance of an oral glucose tolerance test (OGTT) for GH suppression in 21 of 117 patients (18%) and repeat IGF-1 measurements in 52 patients (44%). In 34 of 52 patients (65%) with a median follow-up of 36 months, the subsequent IGF-1 concentration was within the reference interval.
Discovery of "falsely" elevated IGF-1 concentrations may lead to unnecessary testing and physician visits. Although the cause of the "falsely" elevated IGF-1 concentrations during the study period remains to be elucidated, it appears they are caused by a combination of high biological variability and method-specific assay performance issues. Clinicians should consider retesting patients with potentially spurious IGF-1 elevations after some time interval before embarking on more extensive investigations.
我们的目的是确定导致胰岛素样生长因子-1（IGF-1）“假性”升高的频率以及可能的临床和分析因素。
我们对IGF-1浓度高于参考区间的患者进行了回顾性研究。他们是从2007年至2010年期间连续进行IGF-1测量的患者数据库中挑选出来的。
在2747名不同患者中，经临床数据审查后发现117名（4%）患者的IGF-1浓度高于参考区间，被认为是假阳性。IGF-1升高百分比与年龄、性别、体重指数（BMI）、合并症、药物使用、性腺状态、基线生长激素（GH）或胰岛素样生长因子结合蛋白-3（IGFBP-3）浓度之间没有关系。IGF-1浓度异常导致117名患者中的21名（18%）进行了口服葡萄糖耐量试验（OGTT）以抑制GH，并导致52名患者（44%）重复进行IGF-1测量。在52名患者中的34名（65%），中位随访36个月后，随后的IGF-1浓度在参考区间内。
发现IGF-1浓度“假性”升高可能导致不必要的检查和就医。尽管研究期间IGF-1浓度“假性”升高的原因仍有待阐明，但似乎是高生物变异性和方法特异性检测性能问题共同导致的。临床医生在进行更广泛的检查之前，应考虑在一段时间后对IGF-1可能假性升高的患者进行重新检测。
