Growth and Stature Flashcards
What are the three phases of postnatal growth
The infantile phase
The childhood phase
The pubertal phase
What are the characteristic features of infantile phase
Rapid but decelerating growth during he first 2 years of life
What is the overall growth in the infantile phase
30-35cm
What are the characteristic features of the childhood phase
Growth at a relatively constant velocity of 5-7cm per year
What is the most significant endocrine factor for growth in the childhood phase
Growth hormone
What is characteristic of the pubertal phase
a groth spurt of 8-14cm per year due to synergistic effects of increasing gonadal steroid and GH secretion
What ceases first, spinal growth or limb growth
Limb growth
What can be used to estimate a child’s adult height
The mid-parental height
What is mid-parental height useful for
assessing genetic influences on height
What is bone age a measure of
skeletal maturity
How is bone age obtained
by assessing the appearance and shape of the bones of the hand and wrist from a radiograph
What is short stature
defined as a height 2 standard deviation or more below the mean height for children of that gender and chronological age
What are some causes of short stature
Low birth weight and illnesses in infancy
familial
constitutional delay of growth and puberty
endocrine abnormalities (thyroid disease, Cushing’s, vitamin D deficiency or resistance)
Dysmorphic syndromes associated with abnormal skeletal growth (Turner’s syndrome, Down’s syndrome, achondroplasia)
Chronic ilness, malnutrition
Psychosocial problems
Idiopathic
What do children with familial short stature have
short parent(s) with a history of normal puberty
Why does the height of the child begin to drift from the growth curve
The onset of pubertal growth spurt is delayed
Describe the physical examination and biochemical investigations for constitutional delay of growth and puberty (CDGP)
Both are normal
What happens to the growth velocity for children with abnormalities in the endocrine control
Reduced growth velocity and they are usually overweight for their height
What is the most common endocrine cause of short stature
GH deficiency
What might GH deficiency be associated with
other pituitary hormone deficiencies
What does GH stimulate in children
Epiphyseal prechondrocyte differentiation and linear bone growth in children
Gh also stimulates skeletal growth through stimulation of the hepatic synthesis and secretion of insulin-like growth factor-1
What is linked to Cushing’s syndrome in children
Glucocorticoid therapy for asthma, IBD or immunological renal disease
During a clinical examination, what should be looked for
Reduced growth velocity Underweight/ overweight pubertal development Dysmorphic features Features of chronic illness Features of endocrine abnormalities
If a child is found to be hypothyroid, what should be postponed until thyroxine has been adequately replaced
testing of GH
How is GH administered
daily subcut injections
What are some adverse effects of GH injections
benign intracranial hypertension
carpal tunnel syndrome
pancreatitis
increase in growth and pigmentation of naevi
What is the goal of GH deficiency
To achieve IGF-1 levels of about 1 standard deviation above the mean for age/ Tanner stage of pubertal development
Describe the treatment in Turner’s syndrome
slightly higher doses of GH because they have a degree of GH resistance
Describe the relationship between obesity and overall GH production
Obesity may be accompanied by an early onset of puberty and modest overgrowth
Obese children often have diminished overall GH production but high normal serum IGF-1 and GH binding proteins, resulting in tall stature for age prior to puberty
If an oral glucose tolernce test is carried out, what will it show in children with GH secreting adenomas
failure of GH suppression in these children
When is treatment encouraged for tall stature
extreme cases
