Book recommended: Medical Physiology by Jaypee

1. Growth Hormone
(Applied Physiology)
DANISH HASSAN
LECTURER, UNIVERSITY OF SARGODHA

2. Growth Hormone
Hyper-secretion
1. Gigantism
2. Acromegaly
3. Acromegalic-
gigantism
Hypo-secretion
1. Dwarfism
2. Acromicria
3. Simmond Disease

3. Gigantism
 Pituitary disorder characterized by excess growth
of the body.
 The subjects look like the giants with average
height of about 7 to 8 feet

5.  Causes:
 Due to hyper-secretion of GH in childhood or in pre-
adult life before the fusion of epiphysis of bone with
shaft.
 Hyper-secretion of GH is because of tumor of
acidophil cells in the anterior pituitary

6.  Signs and symptoms
 General overgrowth of the person leads to the
development of a huge stature, with a height of
more than 7 or 8 feet.
 The limbs are disproportionately long
 Giants are hyperglycemic and they develop
glycosuria and pituitary diabetes.

7.  Hyperglycemia causes constant stimulation of β-
cells of islets of Langerhans in the pancreas and
release of insulin which leads to degeneration of
these cells and deficiency of insulin and ultimately,
diabetes mellitus is developed
 Tumor of the pituitary gland itself causes constant
headache
 Pituitary tumor also causes visual disturbances. It
compresses the lateral fibers of optic chiasma,
leading to bitemporal hemianopia

8. Acromegaly
 Disorder characterized by the enlargement,
thickening and broadening of bones, particularly
in the extremities of the body.

9.  Causes:
 Hypersecretion of GH in adults after the fusion of
epiphysis with shaft of the bone.
 It is because of tumor of acidophil cells in the
anterior pituitary

10.  Signs and symptoms
1. Acromegalic/gorilla face
 Face with rough features
 Protrusion of supraorbital ridges
 Broadening of nose
 Thickening of lips
 Thickening and wrinkles formation on forehead
 Prognathism (protrusion of lower jaw)

11. 2. Enlargement of hands and feet
3. Kyphosis
4. Thickening of scalp (bulldog scalp)
5. Overgrowth of body hair
6. Enlargement of visceral organs such as lungs,
thymus, heart, liver and spleen (Organomegaly)
7. Hyperactivity of thyroid, parathyroid and adrenal
glands

12. 8. Hyperglycemia and glucosuria, resulting in
diabetes mellitus
9. Hypertension
10. Headache
11. Visual disturbance (bitemporal hemianopia).

16. Acromegalic Gigantism
 Rare disorder with symptoms of both gigantism
and acromegaly.
 Causes:
 Hypersecretion of GH in children, before the fusion
of epiphysis with shaft of the bones causes
gigantism and if hypersecretion of GH is continued
even after the fusion of epiphysis, the symptoms of
acromegaly also appear.

17. Treatment
1. Treatment consists of administration of long-
acting somatostatin analogues.
2. Surgical removal of the tumor in cases that do
not respond to medical treatment.
3. There are also GH receptor antagonists
currently available that can be used to treat
the symptoms of GH excess.

18. Dwarfism
 Pituitary disorder in children, characterized by the
stunted growth.

20.  Causes:
 Reduction in GH secretion in infancy or early childhood
causes dwarfism.
 It occurs because of the following reasons:
1. Tumor of chromophobes, which compresses and
destroys the normal cells secreting GH
2. Deficiency of GH-releasing hormone secreted by
hypothalamus
3. Deficiency of somatomedin C
4. Atrophy or degeneration of acidophilic cells in the
anterior pituitary

21.  Pan-hypopituitarism
 Reduction in the secretion of all the hormones of
anterior pituitary gland.
 This type of dwarfism is associated with other
symptoms due to the deficiency of other anterior
pituitary hormones

22.  Signs and symptoms:
 Primary symptom of hypopituitarism in children is the
stunted skeletal growth.
 Max height of anterior pituitary dwarf at the adult
age is only about 3 feet
 Proportions of different parts of the body are almost
normal. Only the head becomes slightly larger in
relation to the body
 Pituitary dwarfs do not show any deformity and their
mental activity is normal with no mental retardation

23.  Reproductive function is not affected, if there is only
GH deficiency.
 However, during panhypopituitarism, the dwarfs do
not obtain puberty due to the deficiency of
gonadotropic hormone.

24.  Laron dwarfism:
 Genetic disorder, also called GH insensitivity.
 It occurs due to the presence of abnormal growth
hormone secretagogue (GHS) receptors in liver.
 GHS receptors become abnormal because of the
mutation of genes for the receptors.
 GH secretion is normal or high.
 But the hormone cannot stimulate growth because
of the abnormal GHS receptors

25.  Psychogenic Dwarfism
 Dwarfism occurs if the child is exposed to extreme
emotional deprivation or stress.
 The short stature is because of deficiency of GH.
 This type of dwarfism is called psychogenic
dwarfism, psychosocial dwarfism or stress dwarfism

26.  Dwarfism in dystrophia adiposogenitalis
 Also called Fröhlich syndrome
 It is a condition which may be caused by
decreased levels in GnRH in the blood
 It is characterized by:
 Growth retardation
 Retarded sexual development
 Atrophy or hypoplasia of the gonads
 Altered secondary sex characteristics

27.  Dwarfism in Panhypopituitarism
 Panhypopituitarism is the pituitary disorder due to
reduction in secretion of all anterior pituitary
hormones.
 These dwarfs do not attain puberty due to reduced
production of sex hormones from the anterior
pitutary.

28. Acromicria
 Acromicria is a rare disease in adults
characterized by the atrophy of the extremities of
the body.

29.  Causes
 Deficiency of GH in adults causes acromicria
 Secretion of GH decreases in the following conditions:
 Deficiency of GH-releasing hormone from hypothalamus
 Atrophy or degeneration of acidophilic cells in the
anterior pituitary
 Tumor of chromophobes
 Panhypopituitarism

30.  Signs and symptoms
 Atrophy and thinning of extremities of the body,
(hands and feet) are the major symptoms in
acromicria
 Mostly associated with hypothyroidism
 Hyposecretion of adrenocortical hormones also is
common in acromicria
 The person becomes lethargic and obese
 There is loss of sexual functions

31. Simmond Disease
 A disease ascribed by destruction or physiological
exhaustation of the cells of anterior pituitary.
 A rare pituitary disease.
 Also called pituitary cachexia.

32.  Causes
 It occurs mostly in panhypopituitarism, i.e.
hyposecretion of all the anterior pituitary hormones
due to the atrophy or degeneration of anterior
pituitary

33.  Symptoms
 A major feature of Simmond disease is the rapidly
developing senile decay, a 30-years-old person looks
like a 60-years-old person.
 The senile decay is mainly due to deficiency of
hormones from target glands of anterior pituitary, i.e.
the thyroid gland, adrenal cortex and the gonads
 Loss of hair over the body and loss of teeth
 Skin on face becomes dry and wrinkled.
 So, there is a shrunken appearance of facial features.

34. Sheehan Syndrome
 A condition that can occur in a woman who bleeds
severely during childbirth.
 Severe blood loss and decreased blood flow
(ischemia) of the pituitary can also lead to pituitary
insufficiency.
 It is manifested as:
 Hypothyroidism
 Adrenal insufficiency
 Hypogonadism (failure to resume normal menses)
 GH deficiency

35. Case Senario
 A middle-aged male patient consults his family
physician because he has noticed that his hat
and wedding ring are tight and his shoe size has
increased one size during the past couple of
years. He complains of joint aches and pains. He
also states that he has noticed his voice getting
deeper and his facial features being thicker and
coarser when compared to his pictures of 10
years ago.

36.  Laboratory values show increased growth
hormone and IGF-I levels and increased fasting
plasma glucose. An intravenous infusion of
glucose fails to decrease growth hormone levels.
 Brain MRI reveals a tumor localized to the
pituitary.

37.  Q: What is you most probable diagnosis?
 Q: Give 05 evidence to support your diagnosis?
 Q: What are the lab investigations that you might
order to confirm your diagnosis?