Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, Munich, Germany.
Department of Endocrinology, Aalborg University Hospital, Aalborg, Denmark.
Eur J Endocrinol. 2019 Jul;181(1):55-67. doi: 10.1530/EJE-19-0139.
Growth hormone (GH) nadir (GHnadir) during oral glucose tolerance test (OGTT) is an important tool in diagnosing acromegaly, but data evaluating the need to adjust cut-offs to biological variables utilizing today's assay methods are scarce. We therefore investigated large cohorts of healthy subjects of both sexes to define normal GHnadir concentrations for a modern, sensitive, 22 kD-GH-specific assay.
Multicenter study with prospective and retrospective cohorts (525 healthy adults: 405 females and 120 males).
GH concentrations were measured by the IDS-iSYS immunoassay after oral application of 75 g glucose.
GHnadir concentrations (µg/L) were significantly higher in lean and normal weight subjects (group A) compared to overweight and obese subjects (group B); (males (M): A vs B, mean: 0.124 vs 0.065, P = 0.0317; premenopausal females without estradiol-containing OC (OC-EE) (FPRE): A vs B, mean: 0.179 vs 0.092, P < 0.0001; postmenopausal women (FPOST): A vs B, mean: 0.173 vs 0.078, P < 0.0061). Age, glucose metabolism and menstrual cycle had no impact on GHnadir. However, premenopausal females on OC-EE (FPREOC) exhibited significantly higher GHnadir compared to all other groups (all P < 0.0001). BMI had no impact on GHnadir in FPREOC (A vs B, mean: 0.624 vs 0.274, P = 0.1228).
BMI, sex and OC-EE intake are the major determinants for the GHnadir during OGTT in healthy adults. Using a modern sensitive GH assay, GHnadir concentrations in healthy subjects are distinctly lower than cut-offs used in previous guidelines for diagnosis and monitoring of acromegaly.
口服葡萄糖耐量试验（OGTT）时的生长激素（GH）最低点（GHnadir）是诊断肢端肥大症的重要工具，但利用当今的检测方法评估调整截止值以适应生物学变量的需求的数据却很少。因此，我们调查了大量男女健康受试者，以确定现代、敏感、22kD-GH 特异性检测法的正常 GHnadir 浓度。
前瞻性和回顾性队列的多中心研究（525 名健康成年人：405 名女性和 120 名男性）。
OGTT 后，通过 IDS-iSYS 免疫测定法测量 GH 浓度。
与超重和肥胖受试者（组 B）相比，瘦和正常体重受试者（组 A）的 GHnadir 浓度（µg/L）明显更高；（男性（M）：A 比 B，平均值：0.124 比 0.065，P=0.0317；无雌激素含 OC（OC-EE）的绝经前女性（FPRE）：A 比 B，平均值：0.179 比 0.092，P<0.0001；绝经后女性（FPOST）：A 比 B，平均值：0.173 比 0.078，P<0.0061）。年龄、葡萄糖代谢和月经周期对 GHnadir 没有影响。然而，服用 OC-EE 的绝经前女性（FPREOC）的 GHnadir 明显高于所有其他组（均 P<0.0001）。BMI 对 FPREOC 中的 GHnadir 没有影响（A 比 B，平均值：0.624 比 0.274，P=0.1228）。
在健康成年人中，BMI、性别和 OC-EE 摄入是 OGTT 期间 GHnadir 的主要决定因素。使用现代敏感的 GH 检测法，健康受试者的 GHnadir 浓度明显低于以前肢端肥大症诊断和监测指南中的截止值。
