1. Clinical Investigation Unit Testing Endocrinology Rounds July 28, 2010 Selina Liu PGY5 Endocrinology

2. Outline  Background - Dynamic Endocrine Testing  Clinical Investigation Unit - Available Tests  Examples  Growth Hormone Deficiency  Adrenal Insufficiency  Other

3. Background  What can we measure?  basal hormone levels  stimulated or suppressed hormone levels  Why do we do dynamic endocrine testing?  test of secretory reserve

4. Background  INSUFFICIENCY/DEFICIENCY  OVERPRODUCTION Stimulate! Suppress!

5. Available Tests  Which glands/axes can we stimulate or suppress?  Pituitary  Other

6. Pituitary Hormones http://cal.man.ac.uk/student_projects/2002/MNBY9APB/Project_Images/pithormones1.gif

7. Pituitary Hormone Disorders Hormone Underproduction Overproduction GH LH/FSH TSH ACTH Prolactin GH DeficiencyAcromegaly Hypogonadotropic Hypogonadism Central Hypothyroidism Central Adrenal InsufficiencyCushing’s Hyperprolactinemia Central Hyperthyroidism ADH Diabetes Insipidus

8. Central Hyperthyroidism Pituitary Hormone Disorders Hormone Underproduction Overproduction GH LH/FSH TSH ACTH Prolactin GH DeficiencyAcromegaly Hypogonadotropic Hypogonadism Central Hypothyroidism Central Adrenal InsufficiencyCushing’s Hyperprolactinemia ADH Diabetes Insipidus  /normal TSH,  fT3, fT4  /normal ACTH,  cortisol  GH  IGF-1  /normal LH, FSH,  estradiol, testosterone

9. Available CIU Tests GH Deficiency Hypogonadotropic Hypogonadism Central Hypothyroidism Adrenal Insufficiency Insulin Tolerance Test GnRH Stimulation Test TRH Stimulation Test ACTH Stimulation Test CRH Stimulation Test Insulin Tolerance Test Diabetes Insipidus Water Deprivation Test Acromegaly Glucose Tolerance Test Triple Bolus Test

10. Examples  Growth Hormone Deficiency

11. Growth Hormone Secretion GHRH = GH releasing hormone SRIF = somatotropin release inhibiting factor (aka somatostatin) IGFBP = IGF binding protein Kronenberg HM et al. Williams Textbook of Endocrinology. 11th edition. 2008 Saunders Elsevier.

12. Growth Hormone Secretion  pulsatile secretion  healthy adult ~10 pulses/day  longest ~1h after sleep onset  if suspect GH deficiency, random GH level not useful Kronenberg HM et al. Williams Textbook of Endocrinology. 11th edition. 2008 Saunders Elsevier.

13. GH Deficiency - Causes http://www.endo-society.org/guidelines/final/upload/042506_CG_HormoneBook.pdf

14. GH Deficiency – Clinical Presentation  CV Risk factors  abnormal lipid profile, atherosclerosis, insulin resistance  Body composition  increased body fat mass with altered distribution, increased waist:hip, decreased lean body mass  Exercise capacity  reduced muscle mass, impaired max oxygen uptake  QOL  decreased energy, poor concentration, low self-esteem

15. GH Deficiency - Diagnosis  screening test - IGF-1 level ?  IGF-1 – affected by age, obesity, nutrition, comorbidities etc.  Marzullo P et al. 2001 Usefulness of Different Biochemical Markers of the Insulin-Like Growth Factor (IGF) Family in Diagnosing Growth Hormone Excess and Deficiency in Adults J Clin Endocrinol Metab 26:3001-3008

16.  58 healthy, 83 acromegalic, 34 GH deficient subjects  GH deficient: 34 hypopituitarism  prev pituitary tumour/craniopharyngioma/meningioma resection, except for 2 with idiopathic GH deficiency  diagnosed based on arginine-GHRH stimulation test  19 female, 15 male  ages 18-60 2001 J Clin Endocrinol Metab 26:3001-3008

17.  GH deficient subjects had significantly lower mean IGF-1 levels vs healthy control subjects Marzullo P et al. 2001 J Clin Endocrinol Metab 26:3001- 3008

19. Sensitivity: IGF-1 41% Marzullo P et al. 2001 J Clin Endocrinol Metab 26:3001- 3008 therefore – not a good screening test!

20. 2006. J Clin Endocrinol Metab 91:1621-1634

21. Growth Hormone Deficiency Endocrine Society Clinical Practice Guidelines (2006) Recommendation: “Do it” or “Don’t do it” – indicating a judgement that most well-informed people would make Suggestion: “Probably do it” or “Probably don’t do it” – indicating a judgement that a majority of well-informed people would make but a substantial minority would not

22. Growth Hormone Deficiency Endocrine Society Clinical Practice Guidelines (2006) Suggestion: IGF-1  if normal – does not exclude GH deficiency  if in context of pituitary disease, provocative testing is mandatory (level of evidence – high)  if low, and no catabolic disorders, liver disease, indicates severe GH deficiency  may be useful in identifying patients who will benefit from treatment (level of evidence – moderate)

23. Growth Hormone Deficiency  Dynamic tests:  insulin tolerance test (ITT) – GOLD STANDARD  others arginine-GHRH arginine alone clonidine arginine + l-dopa (arginine – decreases SRIF from hypothalamus)

24. Growth Hormone Secretion GHRH = GH releasing hormone SRIF = somatotropin release inhibiting factor (aka somatostatin) IGFBP = IGF binding protein Kronenberg HM et al. Williams Textbook of Endocrinology. 11th edition. 2008 Saunders Elsevier. arginine -

25. Insulin Tolerance Test  first described in 1941

26. Insulin Tolerance Test  To diagnose GH deficiency  also to diagnose adrenal insufficiency, panhypopituitarism  Contraindications:  seizure disorder, cerebrovascular disease, coronary artery disease  can precipitate adrenal crisis  check baseline 08:00 am cortisol – do not do if <100 nmol/L  need close monitoring, physician supervision

28. Growth Hormone Deficiency  Insulin Tolerance Test (ITT)  symptomatic hypoglycemia and fall in BG < 2.2 mmol/L  will increase GH to a maximal level >10  g/L increment of 6  g/L = normal  plasma cortisol should peak at least 496-552 nmol/L Gardner DG & Shoback D (eds) 2007 Greenspan’s Basic & Clinical Endocrinology, Eighth Edition

29. http://ocw.tufts.edu/data/14/134087/134097_medium.jpg Normal ITT (5.6 mmol/L) (4.4 mmol/L) (3.3) (2.2) (1.1 mmol/L)  g/L (275.9 nmol/L) (827.7 nmol/L)

30. TestGH Value < μ g/LReferences Insulin Tolerance Test5.1Biller et al Arginine + GHRH4.1Biller et al Arginine + l-Dopa1.7Biller et al Hexarelin + GHRH3.0Gasperi et al GHRH + GHRP-615.0Popovic et al Kronenberg HM et al. Williams Textbook of Endocrinology. 11th edition. 2008 Saunders Elsevier. Recommended Test Sensitivity (95% CI) to diagnose adult GH deficiency

31. 2002. J Clin Endocrinol Metab 87:2067-2089  39 subjects - multiple pituitary hormone deficiency (MPHD)  13 female, 26 male, aged 26-70  adult onset hypothalamic-pituitary disease  34 matched controls (age, sex, BMI, estrogen status)  14 female, 20 male, age 24-68

32. Biller BMK et al. 2002. J Clin Endocrinol Metab 87:2067-2089

33. 100% sens 100% spec AUC 1.0  MPHD subjects vs. matched controls Biller BMK et al. 2002. J Clin Endocrinol Metab 87:2067-2089

34. To minimize misclassification:  ITT – peak serum GH 5.1  g/L (96% sens, 92% spec)  Arg-GHRH – peak serum GH 4.1  g/L (95% sens, 91% spec)

35. Biller BMK et al.  the ITT and the arginine-GHRH provided the greatest accuracy in discriminating between patients with MPHD and their matched controls  arginine- GHRH test – better preferred by patients  arginine-GHRH test – good alternative to ITT  arginine-L-dopa – reasonable 3 rd option  basal IGF-1 < 77  g/L was 95% specific for GH deficiency Biller BMK et al. 2002. J Clin Endocrinol Metab 87:2067-2089

36. 2006. J Clin Endocrinol Metab 91:1621-1634

37. Growth Hormone Deficiency Endocrine Society Clinical Practice Guidelines (2006) Recommendations:  adults with structural hypothalamic/pituitary disease, surgery or irradiation to these areas, or other pituitary hormone deficiencies should be considered for evaluation for acquired GH deficiency (level of evidence – high)

38. Growth Hormone Deficiency Endocrine Society Clinical Practice Guidelines (2006) Recommendations:  The ITT or arginine-GHRH test is the preferred test for establishing the diagnosis of GH deficiency  but – in those with clearly established recent hypothalamic causes of GH deficiency, i.e. irradiation, arginine-GHRH test may be misleading (level of evidence – high)  GHRH directly stimulates pituitary

39. Growth Hormone Deficiency Endocrine Society Clinical Practice Guidelines (2006) Suggestions:  the presence of deficiencies in > 3 pituitary axes strongly suggests GH deficiency, and in this context, provocative testing is optional (level of evidence – moderate)

40. 2007. Eur J Endocrinol 157:695-700

41. Growth Hormone Deficiency Growth Hormone Research Society Consensus Statement (2007)  ITT, arginine-GHRH, GHRH-GHRP, glucagon tests all well-validated in adults  glucagon useful if ITT contraindicated, if GHRH or GHRP not available  IGF-1 good screening test  normal IGF-1 does not exclude GH deficiency

42. Examples  Adrenal Insufficiency  Primary  low cortisol, high ACTH  Secondary/Tertiary (Central)  low cortisol, low or normal ACTH

43. ACTH and Cortisol Secretion Kronenberg HM et al. Williams Textbook of Endocrinology. 11th edition. 2008 Saunders Elsevier.

44. ACTH and Cortisol Secretion Kronenberg HM et al. Williams Textbook of Endocrinology. 11th edition. 2008 Saunders Elsevier.  pulsatile secretion  circadian rhythm  highest in a.m. 24:0012:0008:0020:00

45. Adrenal Insufficiency - Causes  Primary – adrenal  Secondary – pituitary  Tertiary – hypothalamus

46. Primary Adrenal Insufficiency - Causes www.uptodate.com

47. Secondary Adrenal Insufficiency - Causes www.uptodate.com  Panhypopituitarism  Isolated ACTH Deficiency - ?autoimmune  Familial Cortisol-Binding Globulin Deficiency  Megestrol acetate  Opiates  Traumatic brain injury

48. Tertiary Adrenal Insufficiency - Causes www.uptodate.com  Chronic high dose glucocortioid therapy  Post-cure Cushing’s syndrome  Other  tumours  cranial irradiation  infiltrative diseases i.e. sarcoidosis

49. Adrenal Insufficiency – Clinical Presentation www.uptodate.com

50. Adrenal Insufficiency – Clinical Presentation www.uptodate.com

51. Adrenal Insufficiency – Clinical Presentation www.uptodate.com Central Adrenal Insufficiency (Secondary or Tertiary)  differ from primary:  no hyperpigmentation (ACTH not increased)  no hyperkalemia  dehydration, hypotension less severe  hypoglycemia may occur  GI symptoms less common  local symptoms (headache etc.), other signs of hypopituitarism

52. Adrenal Insufficiency – Diagnosis Steps: 1. To rule out adrenal insufficiency - fasting 08:00 am cortisol  if 08:00 am cortisol >524 nmol/L, adrenal insufficiency excluded  if 08:00 am cortisol <83 nmol/L, adrenal insufficiency confirmed  if 08:00 am cortisol between these values, is borderline – need further testing reviewed in Oelkers W. N Engl J Med 1996; 335(16):1206-1212

53. Adrenal Insufficiency – Diagnosis Steps: 2.If suspect primary adrenal insufficiency, do both 08:00 am cortisol and ACTH  low cortisol and high ACTH - primary  if cortisol normal – rules out primary, but does not exclude mild secondary adrenal insufficiency  in primary adrenal insufficiency – ACTH usually >22pmol/L  low cortisol and low/normal ACTH – secondary/tertiary reviewed in Oelkers W. N Engl J Med 1996; 335(16):1206-1212

54. Oelkers W. N Engl J Med 1996; 335(16):1206-1212 (660 pmol/L ) (0.7 pmol/L ) (6.6 pmol/L) (1380 nmol/L) (8 nmol/L) (83 nmol/L)(276 nmol/L)

55. Adrenal Insufficiency – Diagnosis Dynamic Tests:  to confirm adrenal insufficiency:  high dose short ACTH stimulation test  250  g cosyntropin (Cortrosyn) IV  cortisol/ACTH at -15, 0, 30, 60 min  if peak cortisol >500 nmol/L (preferably >550 nmol/L), rules out primary adrenal insufficiency Oelkers W. N Engl J Med 1996; 335(16):1206-1212

56. Adrenal Insufficiency – Diagnosis ** if suspect recent/mild secondary – can have normal high dose ACTH stimulation test  because of high dose (only need 5  g to maximally stimulate adrenals), and if recent – adrenals will not have atrophied yet  low dose short ACTH stimulation test  1  g cosyntropin (Cortrosyn) IV  cortisol/ACTH at -15, 0, 30, 60 min  normal peak cortisol >500 nmol/L Oelkers W. N Engl J Med 1996; 335(16):1206-1212

57. Adrenal Insufficiency – Diagnosis  if abnormal low dose ACTH stimulation test, require further testing  insulin tolerance test  will confirm if secondary/tertiary adrenal insufficiency Oelkers W. N Engl J Med 1996; 335(16):1206-1212

58. Adrenal Insufficiency – Diagnosis  to distinguish secondary vs. tertiary adrenal insufficiency: CRH stimulation test (if you can get CRH!)  100  g CRH IV  ACTH, cortisol at -15, 0, 30, 60, 90 min  low ACTH = pituitary adrenal insufficiency (secondary)  high ACTH = hypothalamic adrenal insufficiency (tertiary) (values not as well standardized as for ITT) Oelkers W. N Engl J Med 1996; 335(16):1206-1212

60. Other Pituitary Testing  Acromegaly – Glucose Tolerance Test  Hypogonadism - GnRH Stimulation Test  Central Hypothyroidism – TRH Stimulation Test  Panhypopituitarism - Triple/Double Bolus Test  Diabetes Insipidus – Water Deprivation Test

61. Glucose Tolerance Test  to confirm diagnosis of acromegaly Kronenberg HM et al. Williams Textbook of Endocrinology. 11th edition. 2008 Saunders Elsevier.

62. 45y M – 2 months post-pituitary macroadenoma resection  inadequate suppression of GH  persistent acromegaly

63. GnRH Stimulation Test  to confirm diagnosis of hypogonadotropic hypogonadism Kronenberg HM et al. Williams Textbook of Endocrinology. 11th edition. 2008 Saunders Elsevier.

65. TRH Stimulation Test  to confirm diagnosis of central hypothyroidism (and hypoprolactinemia) Kronenberg HM et al. Williams Textbook of Endocrinology. 11th edition. 2008 Saunders Elsevier.

67. Triple Bolus Test  Components:  Insulin Tolerance Test  GH deficiency, adrenal insufficiency  GnRH stimulation test  hypogonadotropic hypogonadism  TRH stimulation test  central hypothyroidism, hypoprolactinemia  if suspect panhypopituitarism

70. 1984. J Neurosurg 61(3):586-590

71. 32 y F – 3 yrs post Rathke’s cleft resection

72. Water Deprivation Test  to confirm diagnosis of central diabetes insipidus http://www.colorado.edu/intphys/Class/IPHY3430-200/image/figure1806.jpg

74. Non-Pituitary Dynamic Tests  Medullary Thyroid Cancer – Calcium stimulation test,  Primary Hyperaldosteronism – Saline suppression test

76. Clinical Investigation Unit - CIU  Liz Froats, RN  Room B5-502 http://dom.lhsc.on.ca/dom/divisions/endo/ciu.htm

78. References  Marzullo P et al. 2001. J Clin Endocrinol Metab 26:3001-3008  Molitch ME et al. 2006. J Clin Endocrinol Metab 91:1621-1634  Biller BMK et al. 2002. J Clin Endocrinol Metab 87:2067-2089  Oelkers W. N Engl J Med 1996; 335(16):1206-1212  Bernstein M et al. 1984. J Neurosurg 61(3):586-590  Kronenberg HM et al. Williams Textbook of Endocrinology. 11 th edition. 2008 Saunders Elsevier.  Gardner DG & Shoback D (eds) Greenspan’s Basic & Clinical Endocrinology, Eighth Edition. 2007 McGraw-Hill.  http://cal.man.ac.uk/student_projects/2002/MNBY9APB/Project_Images/pithormones1.gif http://cal.man.ac.uk/student_projects/2002/MNBY9APB/Project_Images/pithormones1.gif  http://ocw.tufts.edu/data/14/134087/134097_medium.jpghttp://ocw.tufts.edu/data/14/134087/134097_medium.jpg  www.uptodate.comwww.uptodate.com  http://www.endo-society.orghttp://www.endo-society.org  http://www.colorado.edu/intphys/Class/IPHY3430-200/image/figure1806.jpghttp://www.colorado.edu/intphys/Class/IPHY3430-200/image/figure1806.jpg  http://dom.lhsc.on.ca/dom/divisions/endo/ciu.htmhttp://dom.lhsc.on.ca/dom/divisions/endo/ciu.htm