title: Growth hormone and cortisol secretion in the elderly evaluated using the glucagon stimulation test.
abstract: OBJECTIVE
  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.
  
  
  METHODS
  Forty-two subjects (67-88 years) from the geriatric ambulatory unit were submitted and 41 subjects completed the glucagon stimulation test.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Division of Endocrinology - Department of Internal Medicine, Hospital Universitário Clementino Fraga Filho, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil. anabeatrizwinter@yahoo.com.br.
authors.forename: Ana Beatriz Winter
authors.initials: ABW
authors.lastname: Tavares
authors.affiliation: Division of Endocrinology - Department of Internal Medicine, Hospital Universitário Clementino Fraga Filho, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
authors.forename: Ignácio Antônio
authors.initials: IA
authors.lastname: Seixas-da-Silva
authors.affiliation: Division of Endocrinology - Department of Internal Medicine, Hospital Universitário Clementino Fraga Filho, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
authors.forename: Diego H S
authors.initials: DHS
authors.lastname: Silvestre
authors.affiliation: Sergio Franco Medicina Diagnóstica Laboratory, Rio de Janeiro, Brazil.
authors.forename: Maria Fernanda Castelar
authors.initials: MFC
authors.lastname: Pinheiro
authors.affiliation: Division of Endocrinology - Department of Internal Medicine, Hospital Universitário Clementino Fraga Filho, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
authors.forename: Mario
authors.initials: M
authors.lastname: Vaisman
authors.affiliation: Division of Endocrinology - Department of Internal Medicine, Hospital Universitário Clementino Fraga Filho, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
authors.forename: Flávia Lucia
authors.initials: FL
authors.lastname: Conceição
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology; D005260:Female; D005934:Glucagon; D019382:Human Growth Hormone / Q000097:blood*; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D007030:Hypothalamo-Hypophyseal System / Q000502:physiology*; D008297:Male; D010913:Pituitary-Adrenal System / Q000502:physiology*
chemical_list: D019382:Human Growth Hormone; D005934:Glucagon; D006854:Hydrocortisone
keywords: Anterior pituitary; Growth hormone; HPA axis (hypothalamus-pituitary-adrenal); Neuroendocrinology