患有垂体疾病的超重/肥胖成年人在胰高血糖素刺激试验中需要较低的生长激素峰值临界值，以避免生长激素缺乏的过度诊断。
Overweight/Obese adults with pituitary disorders require lower peak growth hormone cutoff values on glucagon stimulation testing to avoid overdiagnosis of growth hormone deficiency.
作者信息
Dichtel Laura E, Yuen Kevin C J, Bredella Miriam A, Gerweck Anu V, Russell Brian M, Riccio Ariana D, Gurel Michelle H, Sluss Patrick M, Biller Beverly M K, Miller Karen K
机构信息
Neuroendocrine Unit (L.E.D., B.M.K.B., K.K.M.) and Department of Radiology (M.A.B.), Massachusetts General Hospital/Harvard Medical School, Boston, Massachusetts 02114; Neuroendocrine Unit (A.V.G., B.M.R., A.D.R., M.H.G.) and Clinical Pathology Core Laboratory (P.M.S.), Massachusetts General Hospital, Boston, Massachusetts 02114; and Division of Endocrinology, Diabetes, and Clinical Nutrition (K.C.J.Y.), Department of Medicine, Oregon Health and Science University, Portland, Oregon 97239.
出版信息
J Clin Endocrinol Metab. 2014 Dec;99(12):4712-9. doi: 10.1210/jc.2014-2830.
CONTEXT
Obesity is associated with diminished GH secretion, which may result in the overdiagnosis of adult GH deficiency (GHD) in overweight/obese pituitary patients. However, there are no body mass index (BMI)-specific peak GH cutoffs for the glucagon stimulation test (GST), the favored dynamic test for assessing adult GHD in the United States.
OBJECTIVE
The objective of the study was to determine a peak GH cutoff level for the diagnosis of adult GHD in overweight/obese individuals using the GST.
DESIGN
This was a retrospective, cross-sectional study.
SETTING
The study was conducted at Massachusetts General Hospital and Oregon Health and Science University.
METHODS
A total of 108 subjects with a BMI ≥ 25 kg/m(2) were studied: healthy controls (n = 47), subjects with total pituitary deficiency (TPD) (n = 20, ≥ 3 non-GH pituitary hormone deficiencies), and subjects with partial pituitary deficiency (PPD) (n = 41, 1-2 non-GH pituitary hormone deficiencies).
INTERVENTION
The intervention consisted of a standard 4-hour GST.
MAIN OUTCOME MEASURES
The main outcome measure was peak GH level on GST.
RESULTS
Using the standard peak GH cutoff of 3 ng/mL, 95% of TPD cases (19 of 20), 80% of PPD (33 of 41), and 45% of controls (21 of 47) were classified as GHD. In receiver-operator characteristic curve analysis (controls vs TPD), a peak GH value of 0.94 ng/mL provided the greatest sensitivity (90%) and specificity (94%). Using a peak GH cutoff of 1 ng/mL, 6% of controls (3 of 47), 59% of PPDs (24 of 41), and 90% of TPDs (18 of 20) were classified as GHD. BMI (R = -0.35, P = .02) and visceral adipose tissue (R = -0.32, P = .03) negatively correlated with peak GH levels in controls.
CONCLUSION
A large proportion of healthy overweight/obese individuals (45%) failed the GST using the standard 3 ng/mL GH cutoff. Overweight/obese pituitary patients are at risk of being misclassified as GHD using this cutoff level. A 1-ng/mL GH cutoff may reduce the overdiagnosis of adult GHD in overweight/obese patients.
背景
肥胖与生长激素（GH）分泌减少有关，这可能导致超重/肥胖垂体疾病患者被过度诊断为成人生长激素缺乏症（GHD）。然而，对于胰高血糖素刺激试验（GST），即美国评估成人GHD时常用的动态试验，尚无针对体重指数（BMI）的特定GH峰值临界值。
目的
本研究的目的是使用GST确定超重/肥胖个体诊断成人GHD的GH峰值临界水平。
设计
这是一项回顾性横断面研究。
地点
该研究在马萨诸塞州总医院和俄勒冈健康与科学大学进行。
方法
共研究了108名BMI≥25kg/m²的受试者：健康对照者（n = 47）、全垂体功能减退（TPD）受试者（n = 20，≥3种非GH垂体激素缺乏）和部分垂体功能减退（PPD）受试者（n = 41，1 - 2种非GH垂体激素缺乏）。
干预
干预措施为标准的4小时GST。
主要观察指标
主要观察指标为GST时的GH峰值水平。
结果
使用标准的GH峰值临界值3ng/mL时，95%的TPD病例（20例中的19例）、80%的PPD病例（41例中的33例）和45%的对照者（47例中的21例）被归类为GHD。在受试者工作特征曲线分析（对照者与TPD）中，GH峰值为0.94ng/mL时具有最高的敏感性（90%）和特异性（94%）。使用GH峰值临界值1ng/mL时，6%的对照者（47例中的3例）、59%的PPD患者（41例中的24例）和90%的TPD患者（20例中的18例）被归类为GHD。在对照者中，BMI（R = -0.35，P = 0.02）和内脏脂肪组织（R = -0.32，P = 0.03）与GH峰值水平呈负相关。
结论
使用标准的3ng/mL GH临界值时，很大一部分健康的超重/肥胖个体（45%）GST结果异常。使用此临界水平，超重/肥胖垂体疾病患者有被误分类为GHD的风险。1ng/mL的GH临界值可能会减少超重/肥胖患者成人GHD的过度诊断。
Zotero 插件