Tavares Ana Beatriz Winter, Seixas-da-Silva Ignácio Antônio, Silvestre Diego H S, Pinheiro Maria Fernanda Castelar, Vaisman Mario, Conceição Flávia Lucia
Division of Endocrinology - Department of Internal Medicine, Hospital Universitário Clementino Fraga Filho, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
Sergio Franco Medicina Diagnóstica Laboratory, Rio de Janeiro, Brazil.
Endocrine. 2017 May;56(2):317-324. doi: 10.1007/s12020-017-1275-8. Epub 2017 Mar 11.
The glucagon stimulation test is a reliable alternative test to assess growth hormone and cortisol secretion, but has not been widely used in the elderly population. The aim of this study was to evaluate growth hormone and cortisol secretion using the glucagon stimulation test in an elderly population without known hypothalamic-pituitary disease and to correlate growth hormone and cortisol peaks with age (less than or greater than 80 years) and body mass index.
Forty-two subjects (67-88 years) from the geriatric ambulatory unit were submitted and 41 subjects completed the glucagon stimulation test.
Median growth hormone peak was 5.99 μg/L and median cortisol peak was 21.6 μg/dL. Growth hormone peak was >3 µg/L in 73.2%, and cortisol peak was >18 µg/dL in 65.8% of patients. There was a statistically significant positive correlation between the growth hormone peak and the cortisol peak. The cortisol peak was significantly different between subjects stratified by growth hormone peak of < or >3 μg/L (15.7 and 21.8 μg/dL, respectively). There was a statistically significant difference in cortisol peak according to age < or > 80 years (22.4 and 18.5 µg/dL, respectively). Considering lower cut-offs recently proposed for growth hormone peak (1.0 μg/L for overweight subjects) and cortisol peak (9.1 μg/dL), only two patients had a growth hormone peak below this value, and all patients had preserved cortisol secretion.
We did find a positive correlation between growth hormone and cortisol peaks in the glucagon stimulation test in the elderly, confirming the capacity of the glucagon stimulation test to stimulate both axes. According to the new proposed cut-points for growth hormone and cortisol, we had 95% of normal growth hormone and 100% of normal cortisol responses.
胰高血糖素刺激试验是评估生长激素和皮质醇分泌的一种可靠替代试验，但在老年人群中尚未广泛应用。本研究的目的是在无已知下丘脑-垂体疾病的老年人群中，使用胰高血糖素刺激试验评估生长激素和皮质醇分泌，并将生长激素和皮质醇峰值与年龄（小于或大于80岁）和体重指数进行关联。
来自老年门诊的42名受试者（67 - 88岁）接受了检查，41名受试者完成了胰高血糖素刺激试验。
生长激素峰值中位数为5.99μg/L，皮质醇峰值中位数为21.6μg/dL。73.2%的患者生长激素峰值>3μg/L，65.8%的患者皮质醇峰值>18μg/dL。生长激素峰值与皮质醇峰值之间存在统计学显著正相关。根据生长激素峰值<或>3μg/L分层的受试者之间，皮质醇峰值有显著差异（分别为15.7和21.8μg/dL）。根据年龄<或>80岁，皮质醇峰值有统计学显著差异（分别为22.4和18.5μg/dL）。考虑到最近提出的生长激素峰值（超重受试者为1.0μg/L）和皮质醇峰值（9.1μg/dL）的较低临界值，只有两名患者的生长激素峰值低于该值，且所有患者的皮质醇分泌均正常。
我们确实发现老年患者胰高血糖素刺激试验中生长激素和皮质醇峰值之间存在正相关，证实了胰高血糖素刺激试验刺激两个轴的能力。根据新提出的生长激素和皮质醇切点，我们有95%的生长激素反应正常，100%的皮质醇反应正常。
