Endocrinolgy Flashcards
what are the two time periods that it is normal for children to cross percentiles?
- during the first 2-3 years of life
2. during puberty
when should children not cross percentiles
during the time from 3yrs until puberty well children do not cross 2 major percentile lines
what is sequential loss of pituitary hormones due to mass effect?
Go Look For The Adenoma Please! G- Growth hormone L- LH F- FSH T- TSH A- ACTH P- Prolactin
what are some causes of delayed bone age? (4)
chronic disease
hypothyroidism
constitutional delay
growth hormone deficiency
what are some causes of low IGF1? (4)
GH deficiency
renal disease
hypothyroidism
malnutrition
What is the normal age for males to enter puberty
9-14
what is the first sign of puberty in most males
Increase in testicular size
at what tanner stage do we see peak growth velocity for males?
tanner stage 4 or 5
what is the testicular size prepuberty? puberty?
prepuberty <2.5cm (4mL)
puberty >2.5cm (4mL)
A 4mL testis corresponds to what in cm?
2.5cm in length
What is the normal age for females to enter puberty
8-13 years
what is the first sign of puberty for most girls
breast development
at what tanner stage do we see peak growth velocity for females?
tanner stage 3
Females attain a peak height velocity of 8-9cm/yr at SMR 2-3
What Tanner stages are associated with menarche
Tanner stage 3-4
what is considered delayed puberty in girls? boys?
absence of secondary sexual characteristics after 13 years of age in girls and 14 years of age in boys
what lab results would you see with primary gonadal failure?
elevated LH/FSH
low testosterone/estrogen
what lab results would you see with permanent or functional pituitary or hypothalamic dysregulation?
low LH/FSH
low testosterone/estrogen
What are key findings with Klinefelter syndrome
47XXY
1 in 600 males
Puberty begins at an appropriate age, penile enlargement and pubic hair
key finding is disproportionately small, firm testes, gynecomastia, infertility
increased learning and behaviour difficulties
treatment= testosterone
List one important cause of primary gonadal failure in males? in females?
Males= Klinefelter syndrome Females= Turner syndrome
Why do we treat girls with Turner syndrome with growth hormone?
not because they are growth hormone deficient but to improve their final adult height
Any female whose height is less than the 3rd %ile what should you consider and what test should you order?
Turner syndrome
karyotype
is precocious puberty more common in girls or boys?
10 times more common in girls
what is the definition of precocious puberty
Pubertal signs before age 8 in girls and before age 9 in boys
Most precocious puberty in girls is idiopathic or pathologic? boys?
central and idiopathic in girls
pathologic in boys
what are the red flags for precocious puberty?
rapid progression
bone age >2 years beyond chronological age
predicted adult height <150cm or >2SD below mid parental height
CNS signs or symptoms
what are 2 common benign conditions in girls often confused with precocious puberty?
- premature thelarche
2. premature adrenarche
what is premature thelarche?
isolated breast development, 6-24 mo of age
breast development does not exceed tanner stage 3
no change in growth %ile
what is premature adrenarche?
pubic hair +/- axillary hair, body odor, acne but no therlarche
early secretion of adrenal androgens (DHEA)
no changes in growth %ile
bone age= height age
associated with PCOS later in life
what are the two broad categories of precocious puberty
central= GnRH dependent (hypogonadotropic hypogonadism) peripheral= GnRH independent (hypergonadotropic hypogonadism)
what is a key feature of precocious puberty
differs from the normal sequence (ie menarche before thelarche)
in girls estrogen dependent effects usually predominate
in boys testes are inappropriately small in size or asymmetric
what is the criteria for diagnosis of diabetes?
FBG >7
RBG ≥ 11.1
2hr OGT ≥11.1
if an infant less than 6 months of age develops diabetes what type is it?
neonatal diabetes
genetic diabetes
tx: sulfonylurea or insulin
what percentage of youth with Type 2DM present with DKA
5-20%
what is the treatment for monogenic diabetes
Tx: sulfonylurea
monogenic diabetes is autosomal dominant
what type of glucose is measure with continuous glucose monitoring?
measuring interstitial glucose
what is the starting dose of insulin for someone with newly diagnosed diabetes
~0.4-0.6 units/kg/day
what are 3 broad causes of DKA
- new diabetic
- deliberate or inadvertent insulin omission
- poor sick day management
what percentage of cases of DKA are complicated by cerebral edema?
0.5-1%
how much insulin do you give for management of hyperglycaemia for a diabetic patient
10-20% of total daily dose by subcutaneous injection or insulin bolus
what is the insulin sensitivity factor
the amount that blood glucose will drop for every unit of rapid insulin given
estimated as 100/TDD
who is considered high risk for type 2 DM and should get screening with FBG?
BMI >85%ile
family history of type 2 DM
high risk populations- Asian, African, indigenous
what is the definition of hypoglycemia
a plasma glucose concentration low enough to cause symptoms and/or signs of impaired brain function
most sources define it as less than 2.8mmol/L (to activate true counter-regulatory response)
consider the context within which blood glucose was measured
what is our body’s response to hypoglycemia
regular ingestion of food with storage of excess as glycogen and fat
gluconeogenesis
glycogenolysis
decreased utilization of glucose by substitution of ketones as primary energy source
what is the main glucose regulator and first defence against hypoglycaemia?
insulin
With hypoglycemia what happens with insulin glucagon, epinephrine and cortisol
decrease insulin increase glucagon increase epinephrine increase cortisol increase growth hormone
what is the main counter-regulatory factor for hypoglycemia
glucagon
what is the glycemic threshold that should prompt behavioural defence (food ingestion)
2.8-3.1
what is included in a critical sample for hypoglycemia?
plasma glucose insulin c-peptide (not on synthetic insulin) BHB (serum ketones) FFA growth hormone cortisol lactate glucagon first urine void for ketones extra plasma can be held for specific tests (total and free carnitine and acylcarnitine, plasma AA, ammonia, urea and lytes, liver function tests)
what is diabetes insipidus
due to loss of vasopressin production
can be central or peripheral
central= loss of ADH production
peripheral= impairment of action (nephrogenic)
low urine osmolality (<300mosmol) increased serum osmolality (>300mosmol) increasing serum sodium signs of dehydration decreased body weight
what is SIADH
inappropriate release of excess activity of vasopressin (ADH)
increased urine osmolality, increased urine Na
oliguria
hyponatremia
serum hypoosmolality
euvolemia or mild hypervolemia
what is the definition of micropenis?
stretched penile length <2.5cm in a term infant
mean penile length= 3.5cm
what is the definition of cliteromegaly
length of clitoris >9mm in a term infant
what is posterior labial fusion?
anogenital ratio >0.5
distance from anus to posterior forchette, divided by distance from anus to base of phallus
what is the workup for someone expected to have 46XX disorder of sexual development?
17 hydroxyprogesterone serum electrolytes glucose ACTH renin testosterone LH FSH
what is the differential for 46XX DSD (6)
congenital adrenal hyperplasia maternal androgen use virtualizing maternal disease ovotesticular DSD XX testicular DSD gonadal dysgenesis
what is the differential for 46XY DSD
leydig cell failure testosterone biosynthetic defect 5 alpha reductase deficiency androgen receptor disorder gonadal dysgenesis rare forms of CAH
what is the workup for someone expected to have 46XY disorder of sexual development?
testosterone dihydrotestosterone LH FSH mullerian inhibiting substance electrolytes glucose
what is the androgen that is most important for virtualizing the external genitalia?
dihydrotestosterone
how do we screen for congenital hypothyroidism
heel prick TSH
what patients with congenital hypothyroidism are missed with newborn screening
those with central congenital hypothyroidism
what are the causes of congenital hypothyroidism?
permanent: thyroid dysgenesis (80%)
dyshormonogenesis (10%)
hypothaamic/pituitary (5%)
transient: intrauterine antithyroid meds
maternal blocking antibody
iodine deficiency
what is the most common malignancy of thyroid nodule?
papillary carcinoma
what is the most common cause of acquired hypothyroidism
Hashimoto thyroiditis (acquired)
what are the two/3 thyroid antibodies
thyroid peroxidase
antithyroglobulin
TSH receptor blocking antibody
what are the findings for Hashimoto thyroiditis
diffuse enlargement of thyroid gland, may be asymmetric
elevated TSH (tx if >10)
positive thyroid peroxidase
antithyroglobulin
what is the cause of Graves disease
thyrotropin receptor stimulating antibody (TRAB)
what is the third most common solid tumor in children and adolescents
thyroid cancer
what is the first line treatment of graves disease?what are other treatment options?
methimazole** (agranulocytosis- labs before starting is CBC, LFTs)
2nd line- PTU (leading cause of fulminant hepatic failure)
radioactive iodine (2nd line- fail to go into remission after 1-2 years after tx or significant side effects with the antithyroid medications)
surgery (3rd line tx- kids with significant eye disease as radioactive iodine can make that worse, bulky thyroid gland or age <5 years)
what is the most common preventable cause of significant cognitive impairment?
congenital hypothyroidism
what is the stress dose of hydrocortisone if age <3, age 3-12, age >12?
age <3: 25mg
age 3-12: 50mg
age >12: 100mg
what is the treatment for adrenal crisis? minor stress versus major stress
minor stress: 2-3x replacement dose of hydrocortisone, or 40mg/m2/day
major stress: hydrocortisone 100mg/m2 IV/IM stat and continued as divided dose q6-8 hours
what is the most common mutation associated with congenital adrenal hyperplasia
21- hydroxylase deficiency
classic- 75% classic salt wasting CAH, the rest are simple virulizing
non-classic- late onset
early morning cortisol <83 nmol/l is highly suggestive of what?
adrenal insufficiency
what is the expected cortisol response to ACTH stimulation test?
≥500 nmol/L
what is the triad for APS1? what is the mutation?
MHA
AIRE gene mutation
1. mucucutaneous candidiasis (1st sign)
2. hypoparathyroidism (usually before puberty)
3. Addisons disease (usually in adolescents)
also has hypothyroidism
what is the triad for APS2?
TAT polygenic 1. autoimmune thyroid disease 2. Addison disease 3. type 1 diabetes
what is the best screening test for Cushings?
24 hour urinary free cortisol- to establish if cortisol excess is present
(not a morning cortisol- use that for adrenal insufficiency)
what is cushing disease
excess pituitary ACTH production
what is the active form of vitamin D
1,25 vitamin D
what is the cause of cushing syndrome <5, >5?
<5: adrenal pathology (ex: McCune Albright Disease)
>5: pituitary disease most common
what are the main hormones that will affect your serum calcium?
- 1, 25- vit D
2. PTH
if checking total calcium what other investigation must you order?
albumin
a change in albumin by 10g/l will change your total calcium by 0.2mmol/l
what effect does pH have on ionized calcium?
alkaLOWsis
alkalosis will lower your ionized calcium
what is the metabolism of vitamin D
Vitamin D is metabolized in the LIVER to 25-OH vit D
25-OH vit D is metabolized in the KIDNEY to 1, 25(OH)2 vit D
what is the storage form of vitamin D?
25-OH vit D
who should you screen for vitamin D deficiency?
known bone disease (rickets, osteoporosis) chronic kidney disease liver disease malabsorption conditions medications (anticonvulsants)
what is the appropriate response to an elevated serum calcium
suppression of PTH
decreased bone resorption
decrease in 1,25- vit D
increase in urinary excretion
what is the appropriate response to a decreased serum calcium
increase of PTH
increased bone resorption
increased 1, 25- vit D
decreased urinary excretion
list 3 clinically significant fractures *impt
- 2 or more long bone fractures by 10 years
- 3 or more long bone fractures by 19 years
- 1 or more vertebral compression fractures (loss of >20% of vertebral body height at any age)
what are the stages of female pubertal development?
breast
hair
growth
menarche
what are the stages of male pubertal development
testicular volume
penile length
hair
growth
what happens with calcium and phosphate as PTH increases? decreases?
PTH increases= Ca increases= Phosphate decreases
PTH decreases= Ca decreases= Phosphate increases
List some causes of hypoparathyroidism (6)
aplasia or hypoplasia (DiGeorge)
autoimmune parathyroiditis (isolated of with type 1 APS)
infiltrative lesions (hemosiderosis and Wilsons disease)
post surgical hypoparathyroidism
post radioactive iodine to thyroid gland
PTH receptor defects
List some causes of vitamin D deficiency
reduced intake or production (poor dietary intake/supplementation, lack of sunlight, malabsorption (fat soluble vitamin), maternal vitamin D deficiency)
severe liver disease
anti seizure medications
renal failure
what is the recommended daily intake of vit d for 0-12 months, 1-3 years, 4-18 years
0-12 months: 400IU
1-3 years: 600IU
4-18 years: 600-1000IU
what is the recommended daily intake of calcium for 0-12 months, 1-3 years, 4-18 years
0-12 months: 250mg
1-3 years: 700mg
4-18 years: 1000-1300mg
what is the treatment of hypocalcemia?
significant symptoms: IV calcium gluconate
oral: calcium carbonate (50-100mg/kg/day in divided doses)
what is the treatment for hypercalcemia?
hyperhydration *
low calcium diet
calcitonin (only works for a short time and repeated doses will lead to decreased effect)
bisphosphonates (take 48-72h to see effect)
steroids- useful for subcutaneous fat necrosis
list 3 key things that might suggest Williams syndrome
elfin facies
supravalvular aortic stenosis
hypercalcemia
what are the clinical features of Rickets
1. widening of growth plates (epiphyses) swelling of wrists and knees rachitic rosary craniotabes (softening of skull bones) 2. softening of the bones genu valgum, varum, wind-swept deformities fractures 3. painful bones - delayed motor milestones
what are the two forms of rickets
calcipenic rickets
phosphopenic rickets
what is the laboratory marker of rickets
ALP
what is the best test for nutritional vitamin D deficiency
25-OH vit D
what screening should be done at diagnosis for Type 2 DM?
peripheral neuropathy- yearly
retinopathy- yearly
nephropathy- yearly (first morning or random ACR)
dyslipidemia- yearly (Fasting TC, HDL, LDL, TG
hypertension- at every clinical encounter, at least biannually)
NAFLD- yearly (ALT and/or fatty liver on ultrasound)
PCOS- yearly
OSA- yearly
depression, binge eating- biannually
what is the target for A1C for most children with type 2 DM
≤ 7.0 %
what children with type 2 DM should get insulin and metformin at diagnosis
A1C ≥ 9
signs of metabolic decompensation (DKA)
insulin should be weaned once glycemic targets are achieved
screening for type 2 DM should be considered every 2 years using a combination of an A1C and a FPG or random plasma glucose in children and adolescents with any of the following conditions
- ≥3 risk factors in non pubertal children beginning at 8 years of age or ≥ 2 risk factors in pubertal children
- obesity
- member of high risk ethnic group (African, arab, asian, hispanic, indigenous or south asian)
- first degree relative with type 2 DM and/or exposure to hyperglycaemia in utero
- signs or symptoms of insulin resistance (acanthosis nigricans, hypertension, dyslipidemia, NAFLD (AST >3x upper limit of normal or fatty liver on ultrasound) - PCOS
- IFG and/or IGT
- use of atypical antipsychotic medications
Children and adolescents <18 years of age with Type 1 DM should aim for an A1C target of what?
A1C ≤ 7.5%
in children <6 particular care to minimize hypoglycemia because of the potential association with layer cognitive impairemnt
when should routine screening for dyslipidemia occur in Type 1 DM
routine screening for dyslipidemia should begin at 12 years of age, repeat screening after 5 years (age 17)
all children with Type 1 DM should be screened for hypertension how often?
biannually
How often should children with Type 1 DM be screened for thyroid problems
at diagnosis and every 2 years with TSH and thyroid peroxidase antibodies
more frequent screening if antibody positive, thyroid symptoms or goiter
when should children with Type 1 DM be screened for celiac?
if they have symptoms of classic or atypical celiac disease
How is hypoglycemia for type 1DM treated at home
mini doses of glucagon if inability or refusal to take oral carbohydrate
(10mcg per year of age)
min 20mcg max 150mcg
an unconscious child >5 at home with hypoglycemia should be treated with what? <5?
1mg glucagon SC or IM
<5 0.5mg glucagon
what screening is required for type 1 DM
neuropathy- children >15 with poor metabolic control should be screened yearly after 5 years of type 1 DM
nephropathy- yearly starting at age 12 in those with type 1 DM >5 years
dyslipidemia- >12 (<12 if BMI >97%ile)
retinopathy- yearly screening starting at age 15 in those with type 1 DM >5 years
hypertension- all children twice annually
what is the average age for menarche?
13
what are some features on physical exam for Turner syndrome?
short stature webbed neck low hairline melanocytic nevi coarctation of the aorta/bicuspid aortic valve cubitus valgus peripheral lymphedema at birth streak ovaries
who needs an MRI for precocious puberty?
all boys
girls <6
a girl with premature adrenarche is at risk for what later in life?
PCOS
6 year old female with premature adrenarche. What is the mostly likely source of androgens?
adrenals
what are the BMI cutoffs for normal, overweight and obese
normal <85th %ile
overweight 85-97th %ile
obese >97 %ile
severely obese >99.9% ile
what are some causes of hypoglycemia with no ketone production (3)
hyperinsulinism (infant of diabetic both, insulin tumor, beck with wiedeman)
fatty acid oxidation disorder
GSD type I
what is the definition of primary amenorrhea
no menses by age 14 in absence of secondary sexual characteristics
or
by age 16 with secondary sexual characteristics
what is secondary amenorrhea
no menses for 3 months or more in a woman who was previously menstruating
what is the normal growth velocity in prepubertal children
5cm/year
What is Chvostek’s sign
Chvostek’s sign is the twitching of the facial muscles in response to tapping over the area of the facial nerve.
what is Trousseau sign
place a blood pressure cuff on the patient’s arm and inflating to 20 mm Hg above systolic blood pressure for 3-5 minutes.
see flexion of the wrist and metacarpal phalangeal joints can be observed with extension of the interphalangeal joints and adduction of the thumb
what are two physical exam findings of hypopituitarism
chvostek’s sign
trousseau sign
what is the equation for BMI
weight in kg/ height in m2
what is the treatment for central precocious puberty
GnRH agonist- Lupron
you take away the GnRH pulses
what are 3 causes of dysmenorrhea and what is the treatment
1. primary dysmenorrhea- absence of other diseases endometriosis 2. PID 3. tumor 4. polyp 5. fibroid 6. miscarriage, ectopic pregnancy 7. imperforate hymen TX: NSAIDS, OCP
what is McCune Albright? what is the triad?
a syndrome of endocrine dysfunction
Triad: precocious puberty, cafe au lait macules, polyostotic fibrous dysplasia
Endocrine manifestations:
gonads- peripheral precocious puberty
thyroid-associated with hyperthyroidism*
kidney- renal phosphate wasting
pituitary- growth hormone excess*
adrenal- rare, cushing syndrome
autonomous hyperfunction of 1 or more glands (thyroid adrenal, pituitary)
what is the average age for girls to have breast bud, pubic hair, PHV, menarche, adult breast
breast bud- 10.5 pubic hair- 11 PHV- 11.6 menarche- 13 adult breast- 14.6
Addisons disease is associated with what lab abnormalities
increased ACTH
increased renin
what is the starting dose for insulin for DKA
0.1 units/kg/hour of short acting insulin
after 1 hour of IV fluids
what is the equation for correcting sodium in dka
measured sodium + 2x [(glucose-5.5)/ 5.5]
fall in corrected sodium is a warning sign for cerebral edema
fall in what two things are associated with cerebral edema
fall in corrected sodium
fall in serum osmolality (2Na +glucose)
what are some risk factors for cerebral edema
age <5
new onset diabetes
IV bolus of insulin
rapid administration of hypotonic fluids
early IV insulin infusion (within the first hour of fluids)
failure of serum sodium to rise during treatment
use of bicarbonate
high initial serum urea
low initial partial pressure or arterial carbon dioxide
what are some symptoms of cerebral edema
headache drowsiness, irritability, confusion voiding decreased HR increased BP coma respiratory arrest with brain herniation
how do you treat cerebral edema?
raise head of bed decrease IV fluids 3%NS or mannitol 5mL/kg over 20 minutes intubation with hyperventilation once stable- imaging
T1D insulin regime
TDD
2/3 TDD in AM- 2/3 intermediate acting; 1/3 rapid acting
1/3 TDD in PM- 2/3 intermediate acting; 1/3 rapid acting
if a patient with type 1 diabetes has recurrent hypoglycemia what should you consider?
celiac disease
addisons
what is the typical insulin regime for insulin pump
Basal insulin- 40-50% TDD
Bolus insulin- 50-60%
combination of carbohydrate ration
correction boluses: sensitivity factor (1 unit of insulin brings down the blood glucose by x mmol/L to target blood glucose)
what should you tell a patient with type 1 DM to do if they have an intercurrent illness and the following blood glucose values: <6 6-14 above 14 (negative or + urine ketones) above 14 (+++ urine ketones)
<6: decrease normal insulin dose at least 10-20%
6-14: give the usual dose of insulin at the normal time. Do not give extra. Recheck in 4 hours.
above 14: give more H/Rp insulin (up to 10% of TDD) NOW. Recheck in 4 hours
above 14, +++ ketones: give for H/Rp insulin (at least 10-20% of TDD) NOW. Recheck in 4 hours.
what is the criteria for DKA
- Hyperglycemia (blood glucose >11 mmol/L
- Venous pH <7.3 or serum bicarbonate <15 mmol/L
- Ketonemia (blood ß-hydroxybuyrate ≥3 mmol/L) or moderate or large ketonuria.
what 3 things do the adrenal glands produce
corticosteroids
mineralocorticoids
androgens
what is the typical daily treatment for adrenal insufficiency
Hydrocortisone 6-8 mg/m2/day DIV TID
what would you see with morning cortisol, corticotropin stimulating test for adrenal insufficiency
morning cortisol <140
ACTH stimulation: peak >500 at 60 minutes excludes adrenal insufficiency
How do you assess mineralocorticoid deficiency for AI
renin and aldosterone
High renin and low aldosterone
what is the treatment for mineralocorticoid deficiency with AI
fludrocortisone (florinef)
what is Cholecalciferol? Calcitriol?
Cholecalciferol = 25(OH)D
Calcitriol / Alfacalcidol = 1, 25(OH)D
what two genetic conditions are predisposed to the development of autoimmune thyroiditis?
Trisomy 21 and Turner syndrome are predisposed to the development of autoimmune thyroiditis.
List some physical exam findings for congenital hypothyroidism
hypothermia acrocyanosis respiratory distress large fontanels abdominal distention lethargy and poor feeding prolonged jaundice edema umbilical hernia constipation large tongue dry skin hoarse cry sinus bradycardia
what is the treatment for hypothyroidism
levothyroxine
what are the electrolyte findings with CAH
hyponatremia
hyperkalemia
acidosis
what are the clinical manifestations of Cushing syndrome
progressive central or generalized obesity marked failure of longitudinal growth hirsutism weakness a nuchal fat pad acne striae hypertension and often hyperpigmentation when ACTH is elevated.
what is the inheritance pattern of nephrogenic diabetes inspidius
x-linked recessive
predominantly in males
how do you screen for primary hypothyroidism?
TSH
what is the optimal time frame for treatment of congenital hypothyroidism?
within the first 7-14 days of life
What is considered an elevated screen for congenital hypothyroidism and what do you do?
elevated: TSH >=15
TSH 15-(30)40- repeat TSH with free T4
TSH >40, repeat labs first to confirm diagnosis, start thyroxine immediately and imaging(nuclear scan/ultrasound) for diagnosis
what causes neonatal hyperthyroidism
Transplacental passage of thyroid stimulating antibodies
identify at risk mother by TRAb titre (fetus should be monitored carefully)
what are some symptoms of hypothyroidism
growth failure weight gain dry skin and hair constipation slow heart rate normal brain development if hypothyroidism starts after first 3 years of life
what are some symptoms of hyperthyroidism
fidgety hyperactive weight loss despite large appetite tremor sweaty hot poor concentration anxiety increased frequency of bowel movements palpitations fatigue
what is the normal growth velocity from 0-12 months
24cm/year
what is the normal growth velocity from 12-24 months
12-18cm/year
what is the normal growth velocity from 24-36 months
8-12cm/year
what is the normal growth velocity in adolescence
8-12cm/year
what is the differential for peripheral precocious puberty in girls? boys? both?
girls: ovarian tumor, ovarian cyst
boys: leydig cell tumor, hCG secreting tumor
both:
exogenous sex steroids
untreated CAH
adrenal tumor
McCune Albright
primary hypothyroidism
what are causes of central precocious puberty?
hypothalamic hamartomas (galactic seizures)
other tumprs
cerebral malformations
idiopathic (majority of girls)
what is the most common cause of delayed puberty in both boys and girls?
constitutional delayed puberty
what are the goals of treatment for precocious puberty?
to preserve adult height
psychosocial concerns associated with precocious pubertal onset
What is the equation for mid parental height
moms height + dads height +/- 13/ 2
what are features of ketotic hypoglycemia
Common form of childhood hypoglycemia 18M-5Y Typically during periods of intercurrent illness, limited food intake Associated with ketonuria and ketonemia diagnosis of exclusion
what are the stages of female pubertal development?
thelarche, adrenarche, growth, menarche
what are the stages of male pubertal development
testicular size, penile length, hair, growth
what is a clue to peripheral precocious puberty in girls
estrogen depends effects predominate
what is a clue to peripheral precocious puberty in boys
testes are inappropriately small
what is most likely for a child with ambiguous genitalia with bilateral masses in the folds
almost always testes, therefore a undervirilized male
what percentage of thyroid nodules are malignant?
20%
much greater than in adults (most thyroid nodules in adults are benign)
what is the pathogenesis of type 1 DM
destruction of the beta cells of the pancreas
80% must be destroyed to affect glycemic control
what is the initial ketone formed in DKA
Acetoacetic acid
what are possible complications of DKA
cerebral edema
DVT
aspiration
cardiac arrhythmias (from electrolyte derangement)
increased amylase and lipase (mild elevation in approx 40%)
acute kidney injury
cognitive impairment
what is required for differentiation of sex organs?
sex determining region on Y chromosome
gonads are biopotential until 6-8 weeks
what are adverse effects of steroids
growth suppression myopathy AVN osetopenia immunosuppression peptic ulceration HTN hyperlipidemia cataracts pseudotumor cerebri
what are the causes of hypercalcemia?
High 5-Is hyperparathyroidism Idiopathic: williams Infantile: subQ fat necrosis Infection: TB Infiltration: Malignancy, sarcoid Ingestion skeletal disorders
what are the main causes of hypocalcemia
vit D deficiency renal insufficiency nephrotic syndrome hypoparathyroidism pseudohypoparathyroidism
what are the possible side effects of growth hormone (4)
SCFE**
pseudotumor cerebri**
worsening scoliosis
hyperglycaemia
who can be treated with GH even if they are not GH defieicnt
Turner syndrome noonan symdrome ISS chronic renal failure PWS SGA
what hormones are secreted by the anterior pituitary gland?
FATPIG F- FSH/LH A- ACTH T- TSH PI-Prolactin G- GH
What are the two hormones secreted by the posterior pituitary gland?
oxytocin
ADH
how do you distinguish between primary and secondary adrenal insufficiency on clinical features and lab work?
Primary adrenal insufficiency: adrenal gland dysfunction
- elevated ACTH
- low cortisol or low mineralcorticoid (hyponatremia/hyperkalemia)
- will see hyperpigmentation (due to pituitary gland trying to stimulate the adrenals and also secreting MSH)
Secondary adrenal insufficiency:
hypothalamic or pituitary dysfunction
-low ACTH
-low cortisol, normal mineralocorticoid (controlled by RAAS system, not hypothalamus or pituitary; thus no hyponatremia/hyperkalemia)
what are the clinical features of hypoparathyroidism? (5)
hypocalcemia delayed teeth eruption/strength scaly skin mucucuntaneous candidiasis cataracts ***all from hypocalcemia
what are the exam findings of hypocalcemia? (6)
muscle spasms
chovtek’s sign: facial nerve spasm on tapping
trousseaus: hand spasm with blood pressure cuff inflated
seizures
tetany
hyperreflexia
which is the only pituitary hormone that is suppressed by a hypothalamic factor?
prolactin- inhibited by hypothalamic release of dopamine
thus in hypothalamic deficiency, you get a decrease in most pituitary hormone secretions but can have increase in prolactin secretion
what is the screening test for growth hormone deficiency?
IGF-1
if this is abnormal then do GH stimulations test
what is a complication of Lupron
sterile abscesses at site of injection
what tests should be included in a critical sample for hypocalcemia? (10)
***MOST IMPORTANT PO4 *** PTH *** Calcium *** 25-OH vIt V 1,24 OH vit D ALP Mg *** consider liver function/enzymes consider renal function urine calcium: creatinine ration *** **2 lavender + 2 green tubes
how do you calculate glucose infusion rate
(%glucose in solution)(TFI)/144
what are the diagnostic criteria for hyperglycemic hyperosmolar syndrome?
severe hyperglycaemia (BG >33)
serum osmolality >330 mol/L
absence of significant ketosis: HCO3>15, urine ketones negative or trace
what is the management of hyperglycemic hyperosmolary syndrome
Bolus NS 20mL/kg
- assume 12-15% fluid deficit
calculate this and correct deficit over 24-48 hours
don’t be afraid to bolus
begin insulin when glucose concentration no longer declining with fluid alone
- 0.025-0.05 units/kg/h
aim to decrease BG by 3-4 mmol/L/h
tend to have higher fluid requirements than DKA
consider lower dose and later initiation of insulin infusion
what are possible causes of central diabetes insipidus?
post head trauma (ie basal skull fracture) post neurosurgery post radiation CNS tumor of the pituitary gland septo-optic dysplasia
You have diagnosed a child with diabetes insipidus and would like to figure out if it’s central vs. nephrogenic (ie. is the posterior pituitary gland not making any ADH or is the kidney unable to respond to ADH?). What is your next best test?
Trial dose of DDAVP (desmopressin), then measure lytes, serum osmolality, urine lytes and urine osmolality.
- if there is a response to the DDAVP and the kidneys are able to concentrate the urine, then this means the post pit is not making ADH! Next step would then be MRI head to r/o tumor
- if there is NO response to the DDAVP, then you’ve made the diagnosis of nephrogenic DI
What is the classic triad of pheochromocytoma?
- Headache - ? from htn
- Palpitations/tachycardia
- Diaphoresis
* ***will have sustained hypertension so if you see palpitations/diaphoresis but you don’t see hypertension, it’s most likely not a pheo
- **spot urinary catecholamines are highly sensitive but NOT specific! Ie. lots of false positives
- best test: 24 hr urinary catecholamines
What is the differential diagnosis for hyperthyroidism? (4)
- Graves disease = most common = thyroid gland stimulated by anti thyroid receptor antibodies
- Subacute thyroiditis
- Suppurative thyroiditis
- Toxic uninodular goitre
During what age group is the following most likely to present:
- complete androgen insensitivity
- partial androgen insensitivity
- complete androgen insensitivity: presents in adolescence since the patient is phenotypically female so no one will suspect the diagnosis until she presents with primary amenorrhea
- partial androgen insensitivity: presents at birth since the patient will have some virilization of external genitalia but not enough
Why do you see hypocalcemia in patients with DiGeorge syndrome?
Hypoplasia or agenesis of parathyroid glands = thus no PTH to regulate serum calcium levels
What is an ACTH stim test used to diagnose?
-how is it done?
Adrenal insufficiency = used to determine whether glucocorticoid insufficiency is due to primary or secondary cause
- steps:
1. measure cortisol level
2. give ACTH
3. re-measure cortisol level to see if it has risen! If it has, then this means that the adrenal gland is working fine and there is a central cause of adrenal insufficiency (hypothalamic or pituitary gland dysfunction). If there is no change, then it is a primary adrenal gland problem (most likely autoimmune)
What are the types of adrenal androgens?
DHEAS = weak androgen Androstenedione = weak androgen Testosterone = strong androgen DHT = strong androgen
- **In adult males: adrenals produce 5% of androgens
- **In adult females: adrenals produce 50% of androgens
What is secreted by medullary carcinoma of the thyroid?
Calcitonin!
-but usually see normal calcium and phosphorus levels
What hormones influence growth? (6)
- Growth hormone
- Insulin
- Insulin Growth Factor -1
- Cortisol
- TSH
- Androgens/estrogen
What is the most accurate way of predicting adult height? What is the least accurate way?
Most accurate - bone age
Least accurate - mid parental height
At what Tanner/SMR stage does axillary hair production occur for:
- boys
- girls
Boys: stage 4
Girls: stage 3
**Remember that girls mature more quickly than boys!
What does the adrenal medulla secrete?
What does the adrenal cortex secrete?
- glomerulosa
- fasciculata
- reticularis
Adrenal medulla:
-catecholamines
Adrenal cortex:
- zona glomerulosa: mineralocorticoids aka aldosterone (think glomerulus in kidney)
- zona fasciculata: glucocorticoids
- zona reticularis: sex hormones + small amt glucocorticoids (“I had sex with reticularis”)
What are the 3 urine catecholamines you test for in cases of possible adrenal medulla tumors?
- VMA
- Metanephrine
- Normetanephrine
What are the steps of sex differentiation in utero?
- If there is a Y chromosome, then the bipotential gonads can differentiate into testes between 6-8 wks.
- The testes produce testosterone (Leydig cells) and anti-Mullerian hormone (Sertoli cells) –> testerone directs formation of the internal male reproductive organs from Wolffian ducts and AMH suppresses development of the Mullerian ducts (ie. preventing female internal reproductive organ formation)
- At 8-12 wks, the testosterone made by testes is changed to DHT (by 5 alpha reductase). DHT causes formation of male external genitalia. If there is no DHT, then female external genitalia develops.
**In infants with CAH, there is an excess of DHT due to build up of intermediate metabolites and thus female babies can have virilization (formation of male external genitalia) while still having normal female internal reproductive organs
What is the classic triad of septo-optic dysplasia?
-diagnostic criteria?
Triad:
- Optic nerve hypoplasia (manifests as nystagmus)
- Pituitary hormone abnormalities: growth failure, hypothyroidism, adrenal insufficiency, diabetes insipidus (varying degrees)
- Midline brain defects: agenesis of septum pellucidum and/or corpus callosum
- need 2/3 of features for diagnosis (this is up for debate)
what is MEN2
MPP
medullary thyroid cancer, pheochromocytoma, parathyroid adenoma
Medullary thyroid cancer: 98% to 100% with MEN2A are affected
Pheochromocytoma, a typically benign (noncancerous) tumor of the adrenal glands: 50% with MEN2A affected
Parathyroid adenoma (a benign tumor) or hyperplasia, meaning increased size of the parathyroid gland: 5% to 10% with MEN2A affected
Diff Dx of secondary amenorrhea:
Central · Systemic illness · Malnutrition · Excessive exercise · Stress · Hypo/hyperthyroidism · Cushing’s syndrome · Prolactinoma · Tumor · Surgery · Radiation Gonadal · PCOS · Knocked up · Ovarian failure
What are 2 tests that can help in the investigation of secondary amenorrhea?
beta-hCG FSH / LH (elevated in ovarian failure, low if central cause) TSH/Free T4 Protactin CBC, ESR, RFT, LFT, lytes Cortisol
Ddx of pubertal gynecomastia
Physiologic gynecomastia Decreased androgen production Congenital abnormalities of testosterone production Drugs that decrease androgen production Estrogen-producing tumors Adrenal disease Liver disease/cirrhosis Starvation
Parents fearful of Listeria and thus have become vegan (no meats, eggs, milk). What dietary deficiency are they at risk for?
Iron ** Vit B12 ** Vit D Calcium Zinc EPA/DHA
what is the most common fatty acid oxidation disorder
MCAD
what is the treatment for hyperinsulinism
IV glucose
diazoxide
somatostatin analogs (octreotide)
what is physiologic gynecomastia? how many boys get this? is it tender? when does it usually resolve?
presence of true breast tissue (not adipose tissue) in males
Up to two thirds of boys develop physiologic gynecomastia during puberty
Boys who have physiologic gynecomastia exhibit palpable, sometimes tender, subareolar breast tissue. Breast enlargement is often asymmetric; tissue may appear only unilaterally or may appear bilaterally, but at different times.
Breast enlargement typically regresses spontaneously after several months, but it may persist for as long as 2 years. Gynecomastia that persists beyond 2 years is unlikely to resolve on its own.
what are the counter regulatory hormones
Insulin Glucagon- opposite of insulin Growth hormone- helps with gluconeogenesis and glycogenolysis Cortisol- helps with gluconeogenesis Epinephrine- helps with gluconeogenesis
what is the best test for precocious puberty?
GnRH stimulation test
if LH increased >5 after stimulation= central
what is the classic tumor associated with central precocious puberty?
hypothalamic hamartoma (gelastic seizures)- secretes GnRH
tanner staging penis
tanner 1 preadolescent tanner 2 minimal change/enlargement tanner 3 lengthens tanner 4 larger; gland and breadth increase in size tanner 5 adult size
tanner staging scrotum
tanner 1 preadolescent tanner 2 enlarged scrotum, pink, altered texture tanner 3 larger tanner 4 larger, SCROTUM DARK tanner 5 adult size
tanner staging breast development
tanner 1 preadolescent
tanner 2 breast budding
tanner 3 breast and areola enlarged, no contour separation
tanner 4 areola and papilla form SECONDARY MOUND
tanner 5 mature, nipple projects, areola part of general breast contour
tanner staging public hair
tanner 1 none
tanner 2 sparse, long downy hairs, lightly pigmented
tanner 3 darker, beginning to CURL, increase amount
tanner 4 coarse, curly, abundant but less than adult
tanner 5 adult distribution, spread to MEDIAL SURFACE OF THE THIGHS
what is the pattern on growth charts for systemic illness versus endocrinopathies
Chronic illnesses cause poor weight gain/weight loss, followed by poor growth. Therefore, if both weight AND height are low it’s likely due to a systemic illness -> “thin and short”
Endocrinopathies tend to cause increased weight and short stature -> “short and fat”
what is the first test to order if you suspect precocious puberty?
The first step in work-up up precocious puberty is to determine whether it is central or peripheral.
LH/FSH
most common germ cell tumor in prepubertal children
yolk sac tumor
high AFP
Give the most common reason for false positive newborn screen for congenital hypothyroidism
Screening too early (before 48hrs)
What is best test to determine initial dose of thyroid replacement in Hashimoto’s
TSH
how do you determine anticipated adult height
MPH +/- 8.5cm
what are two recommendations to ensure maximal absorption of levothyroxine?
take on an empty stomach
do not take it with soy/milk
after being diagnosed with congenital hypothyroidism and starting treatment when should you repeat TSH?
in 2 weeks and every 4-6 weeks after a dose change, every 3 months once stable
At what age are most children sure of their gender identity?
4
Most common sign on exam for hypocalcelmia
Most common sign on exam: hyperreflexia!
Chvostek sign – tapping on the facial nerve makes the side of their mouth twitch
Trousseau sign – sustained BP cuff ~20mmHg above systolic BP for 3 minutes produces a carpopedal spasm (more specific)
what is one cause of congenital growth hormone deficiency? acquired growth hormone deficiency?
congenital- septo-optic dysplasia
acquired- craniopharyngioma
what is the main difference between SIADH and CSW
SIADH- low urine output
CSW- high urine out and hypovolemia
SIADH hydration status: euvolemia urine output: low Serum Na: low serum osmolality: low urine Na: high urine osmolality: high
CSW: hydration status: HYPOVOLEMIA urine output: HIGH Serum Na: low serum osmolality: low urine Na: high ++ urine osmolality: high
DI versus SIADH
SIADH hydration status: euvolemia urine output: low Serum Na: low serum osmolality: low urine Na: high urine osmolality: high
DI: hydration status: hypovolemia urine output: high Serum Na: high serum osmolality: high urine Na: low urine osmolality: low
TSH <40 on newborn screen for congenital hypothyroidism what would you do?
repeat TSH and free T4 and followup in 1-2 weeks
what are the two main causes of primary adrenal insufficiency? secondary?
Addisons
CAH
secondary or central: withdrawal of glucocorticoid administation
how might a patient with Addisons disease present?
non-specific symptoms weight loss fatigue hypotension hyperpigmentation hyponatremia * hyperkalemia * hypoglycemia *
what is the screening test for adrenal insufficiency
early morning cortisol
stress doses for illness or surgery for someone who has been on chronic glucocorticoids should continue for how long?
continue stress dosing for 6-12 months after discontinuation of glucocorticoids
how much vitamin D should be given to pregnant and lactating mothers especially during the winter months?
consider 2000IU
how much vitamin D during the first year of life for someone living north of the 55th parallel (Edmonton)
800IU vit D
what is osteoporosis
skeletal disorder characterized by decreased bone strength
usually caused by an underlying medical disorder or medication
look for clinically significant fractures
1. 2 or more long bone fractures by 10 years
2. 3 or more long bone fractures by 19 years
3. 1 or more vertebral compression fractures (loss of >20% of vertebral body height at any age)
what are 2 causes of primary osteoporosis? 5 causes of secondary osteoporosis?
- osteogenesis imperfecta
- Ehlers Danlos
other connective tissue problems
secondary:
1. GH
2. Hyperthyroidism
3. vit D deficiency
4. chronic illness
5. physical inactivity
what test should be done if you have an infant <6 mo of age with diabetes
GENETIC TESTING
infants less than 6 months of age do not get type 1 DM
would be neonatal diabetes
what is the diagnostic criteria for PCOS
- evidence of hyperandrogenism
2. abnormal uterine bleeding pattern
who should have lipid screening
Positive family history of dyslipidemia or premature cardiovascular disease (1st or 2nd degree relative)
< 55 years of age for males
< 65 years of age for females
If family history unknown or in presence of other cardiovascular disease factors
Overweight (BMI > 85th%) or Obese (BMI > 95th%)
Hypertension (BP > 95th %)
Cigarette smoking
Diabetes Mellitus
Start between the ages of 2-10 years
Retest q 3-5 years- if initial screen normal
screen with a fasting lipid profile
Pharmacotherapy (statin) should be considered in children > 8 years if:
LDL-C >???
Pharmacotherapy (statin) should be considered in children > 8 years if:
LDL-C > 4.9 mmol/L
LDL-C > 4.1 mmol/L + family history of early heart disease or > 2 risk factors present
LDL-C > 3.4 mmol/L + Diabetes Mellitus
what is the target for LDL while on statin?
LDL-C < 3.0 mmol/L
