Departments of Chemical Pathology & Immunology and Paediatric Endocrinology, Leeds General Infirmary, Leeds, UK.
Clin Endocrinol (Oxf). 2000 Jun;52(6):727-733. doi: 10.1046/j.1365-2265.2000.00996.x.
The combined pituitary function test is routinely used in the endocrine investigation of short children. The TRH and luteinising hormone-releasing hormone (LHRH) response tests have been shown to be of minimal value in adults. We have evaluated the clinical utility of these tests in the context of combined pituitary function testing in children.
A retrospective analysis of basal hormone measurements and pituitary stimulation tests in relation to clinical assessment of pituitary function.
One hundred and twenty-six children, 82 boys and 44 girls, aged 2-17 years, who had undergone pituitary function testing were studied.
The TSH response to TRH stimulation correlated directly with basal plasma TSH but not basal plasma total T4. In patients with an impaired response to stimulation, basal TSH concentrations were <2.0 mIU/l and significantly lower than in patients with a normal response (P < 0.0001). An impaired response to TRH stimulation had a positive predictive value of 0.43 and a negative predictive value of 0.90 for the diagnosis of hypopituitarism. A basal TSH concentration of <2.0 mIU/l had a positive predictive value of 0.22 and a negative predictive value of 0.92. A low basal T4 (normal range 60-140 nmol/l) in combination with an inappropriately low or normal basal TSH was always associated with a diagnosis of hypopituitarism. The responses of plasma LH and FSH to LHRH stimulation correlated directly with basal plasma LH and FSH concentrations. Basal gonadotrophin concentrations, basal sex hormone concentrations or response to LHRH stimulation could not distinguish patients with constitutional delay of growth and puberty from those with hypopituitarism. There was no apparent relationship between either basal gonadotrophin concentrations or response to LHRH stimulation and clinical assessment of pituitary function. In patients ≥13 years with constitutional delay of growth and puberty the median and interquartile ranges of basal LH and FSH were 1.4 IU/l (0.7-3.6) and 2.6 IU/l (2.2-5.2) respectively. The three hypopituitary patients in this study with chronological age ≥13 years had undetectable concentrations of both gonadotrophins. The response of LH and FSH to LHRH stimulation was significantly lower in patients ≥13 years with clinical hypopituitarism than in those with intact pituitary function (P <0.02).
TRH and LHRH tests in children with short stature appear to have little value over and above the baseline hormone measurements. An abnormal response to hormone stimulation is not diagnostic of hypothalamic-pituitary disease. We have demonstrated that neither TRH nor LHRH stimulation tests should be routinely used in the investigation of children with short stature.
联合垂体功能试验常用于矮小儿童的内分泌检查。促甲状腺激素释放激素（TRH）和促黄体生成素释放激素（LHRH）反应试验在成人中已被证明价值不大。我们在儿童联合垂体功能检查的背景下评估了这些试验的临床实用性。
对基础激素测量和垂体刺激试验与垂体功能临床评估的相关性进行回顾性分析。
研究了126名年龄在2至17岁之间接受过垂体功能检查的儿童，其中82名男孩和44名女孩。
TRH刺激后促甲状腺激素（TSH）反应与基础血浆TSH直接相关，但与基础血浆总甲状腺素（T4）无关。在刺激反应受损的患者中，基础TSH浓度<2.0 mIU/l，明显低于反应正常的患者（P<0.0001）。TRH刺激反应受损对垂体功能减退诊断的阳性预测值为0.43，阴性预测值为0.90。基础TSH浓度<2.0 mIU/l的阳性预测值为0.22，阴性预测值为0.92。低基础T4（正常范围60 - 140 nmol/l）与基础TSH不适当降低或正常相结合，总是与垂体功能减退的诊断相关。血浆促黄体生成素（LH）和促卵泡生成素（FSH）对LHRH刺激的反应与基础血浆LH和FSH浓度直接相关。基础促性腺激素浓度、基础性激素浓度或对LHRH刺激的反应无法区分体质性生长和青春期延迟患者与垂体功能减退患者。基础促性腺激素浓度或对LHRH刺激的反应与垂体功能的临床评估之间没有明显关系。在年龄≥13岁的体质性生长和青春期延迟患者中，基础LH和FSH的中位数及四分位数间距分别为1.4 IU/l（0.7 - 3.6）和2.6 IU/l（2.2 - 5.2）。本研究中3名年龄≥13岁的垂体功能减退患者两种促性腺激素浓度均检测不到。年龄≥13岁的临床垂体功能减退患者中LH和FSH对LHRH刺激的反应明显低于垂体功能正常的患者（P<0.02）。
身材矮小儿童的TRH和LHRH试验似乎在基线激素测量之外价值不大。激素刺激反应异常不能诊断下丘脑 - 垂体疾病。我们已证明TRH和LHRH刺激试验均不应常规用于身材矮小儿童的检查。
