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1. ADRENAL FUNCTION TESTS
Adrenal glands
 Two small organs located above the
kidneys.
 Have two functionally distinct parts
◦ Outer cortex(with three zones)
◦ Inner medulla – Catecholamines

2. HORMONES
Adrenal cortex zone Adrenocorticosteroid
hormone
Zona Glomerulosa Mineralocorticoids
Zona Fasciculata Glucocorticoids
Zona reticularis Androgens

3.  Cyclopentanoperhydrophenanthrene
nucleus as their basic structure
 All steroid hormones are derived from
cholesterol(major source -
circulation)
 Most reactions catalyzed by enzymes
of Cyt P450 family.
 Liver is the major site for steroid
catabolism

4. Glucocorticoids
 21C steroids
 Secreted in response to ACTH (secreted by
pituitory), which is in turn controlled by CRH.
 Cortisol (also known as hydrocortisone) is
the predominant glucocorticoid
 Mainly involved in the regulation of
carbohydrate, lipid and protein metabolism.
 Powerful anti-inflammatory hormone.
 Cortisol exerts negative feedback on CRH
and
ACTH secretion
 Diurnal variation – highest in early morning,
lowest near midnight.

5. Mineralocorticoids
 21 C steroid
 Aldosterone is the most potent
naturally occurring mineralocorticoid.
 Have effects on water and electrolyte
balance.(sodium conservation,
potassium and H ion excretion )
 Regulated by renin –angiotensin
system

6. Sex steroid hormones
 Secreted by zona reticularis.
 Dehydroepiandrosterone,
dehydroepiandrosterone
sulfate(DHEA-S), Androstenedione-
Peripheral conversion to
testosterone.
 Estrogen production negligible in
adrenal cortex.
 Regulation not well understood yet

7. ADRENAL HYPERFUNCTION ADRENAL
HYPOFUNCTION
Cushing’s syndrome: Primary defect
in adrenal gland (Adrenal adenoma,
adrenal carcinoma etc)
Addison’s disease(primary
adrenal insufficiency)
Cushing’s disease/
Hyperpituitarism:Excess ACTH from
pituitary –pituitary adenoma
Secondary adrenal
insufficiency:hypothalamic/
pituitary disorder -
impaired secretion of
CRH/ACTH
Androgen-secreting tumors of
Ovaries, Testes, Ectopic ACTH by
other tumors
Administration of ACTH
Primary hyperaldosteronism/Conn’s
syndrome

8. Adrenal function tests
 Help in diagnosis and monitoring of
adrenal hypo/hyperfunction disorders.
 DHEA may be measured to determine
cause of hirsuitism, amenorrhoea,
infertility or precocious puberty in
females.

9. Adrenal function tests
 Plasma Cortisol level
 Plasma ACTH level
 ACTH stimulation test/ CoSyntropin
test
 Corticotropin-releasing hormone(CRH)
stimulation test
 Dexamethasone Suppression Test
 17-Hydrocortisol level
 Urinary free Cortisol
 Estimation of aldosterone in blood

10. Adrenal function tests
contd…
 Urinary excretion of steroids
 Serum electrolytes
 Estimation of plasma renin activity
 Insulin induced hypoglycemic
stimulation test.
 17 alpha- Hydroxyprogesterone levels
 DHEA estimation

11. Plasma Cortisol level
 Diurnal rhythm
◦ Secretion maximum in morning
◦ Minimum at midnight
 Normal range
◦ 5-25 microgm/dl in morning(8 am)
◦ 2-5 microgm/dl in night(10 pm)
 Determined by immunoassay
(ELISA/CLIA/RIA)
 Loss of diurnal rhythm may be an early
indication of lesion at any point in
hypothalamic –pituitary- adrenal axis

12. Plasma ACTH
ACTH CORTISOL PROBABLE
DISORDER
Low High Primary
hyperadrenalism
Low Low Secondary
adrenal
insufficiency
High Low Primary
adrenocortical
insufficiency
High High Pituitory
adenoma
(Cushings

13. Synacthen test/ACTH stimulation
tests
 Used to assess adrenal reserve
capacity
 Used to demonstrate the failure of
adrenal gland to produce cortisol in
response to ACTH
 Stimulation of adrenal cortex by
synthetic
ACTH(eg:synacthen/cosyntropin)inject

14.  Normal response shows a rise in
serum cortisol > 18microg/dl within
60mts of i.v administration of
synacthen
 A person with primary adrenal failure
doesnot respond.( rise <18microg/dl)
 Confirms the diagnosis of Addison’s
disease

15. CRH Stimulation tests
 Definitive to differentiate pituitary
causes from other causes
 Rise in ACTH secretion and cortisol
levels following injection
 If there is no ACTH response after
CRH stimulation tests, the disease is
of pituitary origin

16. Dexamethasone Suppression Tests
 Used in diagnosis of Cushing’s syndrome.
Low dose Dexamethasone Suppression Tests
 Dexamethasone is a potent suppressor of
pituitary ACTH secretion and thereby cortisol
level,causing 50% fall in serum cortisol with a
dose as low as 1mg
 Patient takes dexamethasone tab at night and
plasma cortisol is determined at 8 am the
following morning
 Morning cortisol <5microgm/dl rules out
adrenal tumors.

17. High dose dexamethasone
suppression test
 Done to confirm Cushings disease
 Administer 2mg dexamethasone every
6 hrs for 2 days & cortisol measured
next day morning.
 This dose suppresses plasma cortisol
in Cushings disease.(drop atleast
50%)
 If plasma cortisol level is not
suppressed, adrenal tumors producing
high levels of cortisol or ectopic ACTH
producing tumors are usually the

18. Urinary excretion of steroids
 Urinary steroids are 17 ketosteroids
and 17 hydroxy steroids
 17 ketosteroids are derived from both
adrenal steroids and androgen from
gonads, major contribution by cortisol
and cortisone
 17 hydroxy steroids are derived mainly
from adrenal steroids
 Diagnostic value to assess functional
status of adrenal cortex, particularly in
females

19. Estimation of aldesterone in
blood
 Increased levels are seen in primary
hyperaldosteronism /Conn’s syndrome
and bilateral adrenal hyperplasia
 Decreased aldosterone levels are
seen in Addison’s disease

20. Estimation of plasma renin
activity
 Helps to differentiate between primary
and secondary hyperaldosteronism
 Enzyme activity is high in secondary,
low in primary hyperaldosteronism

21. Urinary free Cortisol
 In plasma 70% cortisol is bound to
cortisol binding globulin/transcortin
 20% cortisol is bound to albumin
 Rest is free,which is the biologically
active form
 A definite fraction of unbound/free
cortisol is exreted in urine unchanged
 24 hr urine sample is collected
 Estimation of urinary free cortisol is a
sensitive index of adrenal activity:
Hyper/Hypofunction.

22. Lab findings in Adrenal
hyperfunction
Cause Plasma
cortisol
Urinary
cortisol
Plasma
ACTH
Dexamethasone
suppression
Adrenal
adenoma
Increased Increased decreased No suppression
Adrenal
carcinoma
Increased Increased decreased No suppression
Pituitory
adenoma
Increased Increased Increased Suppression with
high dose
Ectopic ACTH Increased Increased Increased No suppression

24. Lab findings in Adrenal
hypofunction
Cause for
adrenal
insufficienc
y
Plasma
cortisol
Urinary
cortisol
Plasma
ACTH
ACTH
stimulation
CRH
stimulation
Primary low low High No effect No effect
Secondary low low Low Normal/
exaggerate
d
No effect

26. Lab findings in Conn’s
syndrome
 Plasma Aldosterone levels are high
 Plasma renin activity is decreased due
to feedback
 Serum electrolytes-hypernatemia,
hypokalemia
 pH is elevated(hypokalemic alkalosis)
 Osmolality is elevated

27. Sex hormones & investigations
in Infertility

28. Commonly measured hormones for
evaluation of infertility are:
 FSH
 LH
 Testosterone
 Prolactin
 Estradiol
 Anti-Mullerian Hormone
 TSH
 Progesterone
 Inhibin-B

31. Assignment Questions( 5*4 =
20 marks)
1. List the adrenal function test with
significance of each.
2. List the lab findings in adrenal
hyperfunction.
3. List the lab findings in adrenal
hypofunction.
4. In tabular form, give the pattern of
hormone levels in various endocrine
abnormalities in males and females.

32. Thank you