Growth hormone deficiency overview

Revision as of 14:08, 27 September 2017 by Medhat (talk | contribs)
Jump to navigation Jump to search

Growth hormone deficiency Microchapters

Home

Patient Information

Overview

Historical Perspective

Classification

Pathophysiology

Causes

Differentiating Growth hormone deficiency from other Diseases

Epidemiology and Demographics

Risk Factors

Screening

Natural History, Complications and Prognosis

Diagnosis

Diagnostic Criteria

History and Symptoms

Physical Examination

Laboratory Findings

X Ray

CT

MRI

Echocardiography or Ultrasound

Other Imaging Findings

Other Diagnostic Studies

Treatment

Medical Therapy

Surgery

Primary Prevention

Secondary Prevention

Cost-Effectiveness of Therapy

Future or Investigational Therapies

Case Studies

Case #1

Growth hormone deficiency overview On the Web

Most recent articles

Most cited articles

Review articles

CME Programs

Powerpoint slides

Images

American Roentgen Ray Society Images of Growth hormone deficiency overview

All Images
X-rays
Echo & Ultrasound
CT Images
MRI

Ongoing Trials at Clinical Trials.gov

US National Guidelines Clearinghouse

NICE Guidance

FDA on Growth hormone deficiency overview

CDC on Growth hormone deficiency overview

Growth hormone deficiency overview in the news

Blogs on Growth hormone deficiency overview

Directions to Hospitals Treating Growth hormone deficiency

Risk calculators and risk factors for Growth hormone deficiency overview

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Mohammed Abdelwahed M.D[2]

Overview

Historical Perspective

In the mid-1940s, bovine GH has been purified for the first time then, growth hormone was isolated from the human pituitary gland in 1956. 7700 children in the United States and 27,000 children worldwide were given GH extracted from human pituitary glands. In 1981, Genentech developed the first recombinant human GH.

Classification

Growth hormone deficiency can be classified by nature into congenital type in which infants show symptoms such as hypoglycemia, neonatal growth failure, neonatal jaundice, and asphyxia or acquired type presents with severe growth failure, delayed bone age, delayed puberty.

Pathophysiology

The somatotroph cells of the anterior pituitary gland produce growth hormone. GH best-known effect is increasing body mass. GH causes epiphyseal plate widening and cartilage growth. GH deficiency results in alterations in the physiology of different systems of the body, manifesting as altered lipid metabolism, increased subcutaneous visceral fat, decreased muscle mass. Genetic basis of congenital growth hormone deficiency depends on many genes, for example, POU1F1 gene mutations are the most common known genetic cause of the combined pituitary hormone deficiency. Gene deletions, frameshift mutations, and nonsense mutations of GH1 gene have been described as causes of familial GHD.

Causes

Causes of growth hormone deficiency could be congenital or acquired. Congenital causes include genetic mutations in POU1F1PROP-1, and GH-1 genes. Structural causes can cause growth hormone deficiency such as optic nerve hypoplasiaagenesis of corpus callosumsepto-optic dysplasiaempty sella syndrome, and holoprosencephaly. Acquired causes can cause growth hormone deficiency such as GHD following brain surgery and radiation therapy for brain tumors, central nervous system infection, craniopharyngiomapituitary adenoma.

Differentiating growth hormone deficiency from Other Diseases

Growth hormone deficiency in children must be differentiated from other diseases that cause short stature in children such as achondroplasia, constitutional growth delay, familial short stature, growth hormone resistance, Noonan Syndrome, panhypopituitarism, pediatric hypothyroidism, psychosocial short stature, short stature accompanying systemic disease, short stature from abuse and neglect, Silver-Russell Syndrome, and Turner Syndrome.

Epidemiology and Demographics

If left untreated, patients with growth hormone deficiency may progress to develop delayed postnatal growthdelayed bone agedelayed puberty, infantile fat distribution, and infantile voice. Common complications of growth hormone deficiency include osteopeniadyslipidemiadelayed puberty, and higher mortality rates than normal subjects. Prognosis is generally good with treatment. GH treatment can improve GH-deficient adults symptoms. Since recombinant DNA–derived growth hormone became available, most children with growth hormone deficiency reach normal adult stature.

Risk Factors

There are no established risk factors for growth hormone deficiency.

Screening

Genetic screening of growth hormone deficiency is indicated for patients with early and severe symptoms. GHD patients have been screened for mutations in the GH1 and GHRH gene. Understanding of genetic contributions to GHD opens the possibility for a more rational approach to the diagnosis and management of GHD.

Natural History, Complications, and Prognosis

If left untreated, patients with growth hormone deficiency may progress to develop delayed postnatal growthdelayed bone agedelayed puberty, infantile fat distribution, and infantile voice. Common complications of growth hormone deficiency include osteopeniadyslipidemiadelayed puberty, and higher mortality rates than normal subjects. Prognosis is generally good with treatment. GH treatment can improve GH-deficient adults symptoms. Since recombinant DNA–derived growth hormone became available, most children with growth hormone deficiency reach normal adult stature.

Diagnosis

History and Symptoms

The hallmark of growth hormone deficiency is growth failure. The most common symptoms of GHD in infants are delayed Bone age, perinatal asphyxiahypoglycemia, and jaundice. Adults symptoms include increased lean body mass, fractures of the lumbar spine, and osteopenia.

Physical Examination

Patients with growth hormone deficiency usually look tired and less energetic than normal subjects. Extremities show Clubbing, muscle atrophy, neonatal jaundice, neonatal cyanosis. Head may show infantile facies, delayed dentition, and brittle hair. Children may show hyporeflexia and delayed puberty.

Laboratory Findings

An immediate investigation should be started in severe short stature defined as a short child more than 3 sd below the mean of children at the same age. Measurement of a random serum GH level alone is not helpful. Measurement of Insulin-like growth factor I (IGF-I) and Insulin-like growth factor binding protein-3 (IGFBP-3) is more helpful than GH level alone.

GH stimulation tests is indicated for most patients suspected to have GHD. If the clinical and other laboratory criteria are sufficient to make the diagnosis of GHD, there is no need to perform the test. Pharmacologic stimuli include clonidineglucagonarginine, and insulin-induced hypoglycemia. Administration of sex steroids for a few days prior to the provocative GHtesting reduces the chance of a false-positive result.

Electrocardiogram

X-ray

An x-ray may be helpful in the diagnosis of delayed bone age associated with growth hormone deficiency.

CT scan

Pituitary CT scan may be helpful in the diagnosis of growth hormone deficiency if an MRI is not available.

MRI

Brain MRI may be helpful in the diagnosis of growth hormone deficiency. On T1-weighted imaging, a clear demarcation can be made between the adenohypophysis and the neurohypophysis, which appears as hyperintense. Other pituitary abnormalities such as anterior pituitary hypoplasiapituitary stalk agenesis, and posterior pituitary ectopia can be diagnosed using MRI.

Ultrasound

There are no ultrasound findings associated with growth hormone deficiency.

Other Imaging Findings

There are no other imaging findings associated with growth hormone deficiency.

Other Diagnostic Studies

There are no other diagnostic studies associated with growth hormone deficiency.

Treatment

Medical Therapy

Growth hormone (GH) is indicated for children with GH deficiency whose epiphyses are open. The dose for children is between 0.16 and 0.24 mg/kg/week, divided into once daily injections. Serum levels of insulin-like growth factor I (IGF-I) should be measured several weeks after beginning GH treatment or making a dose adjustment. GH side effects include headachesIdiopathic intracranial hypertensionSlipped capital femoral epiphysis, worsening of existing scoliosisPancreatitis, and Gynecomastia. There is a possible role for GH in cancer risk.

Surgery

Surgical intervention is not recommended for the management of growth hormone deficiency.

Primary Prevention

There are no established measures for the primary prevention of growth hormone deficiency.

Secondary Prevention

References


Template:WikiDoc Sources