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Flashcards in Endocrinology q-bank Deck (79):

Which antibodies are most commonly seen in Hashimoto thyroiditis?

Thyroid antiperoxidase antibody (anti-TPO) and antithyroglobulin antibody seen in 90% of patients


What should you consider in a patient with hypoparathyroidism, Addison's, recurrent candidiasis and skin changes?

APCED Auto-immune polyendocrinopathy ectodermal dysplasia - autoimmune polyendocrinopathy, candidiasis, ectodermal dysplasia


With nephrogenic DI, what is the most common inheritance pattern? Name 4 acquired causes of nephrogenic DI.

X-linked, some forms can be AD or AR Acquired causes: hypercalcemia hypokalemia lithium rifampin methicillin kidney disease


In physiologic adrenarche, describe: - age at which acceptable - what blood / urine markers are seen - bone age findings - long-term prognosis - tests to perform if unsure if physiologic

Adrenarche (increase in adrenal steroids) resulting in hair, body odour and skin changes and maybe slight growth acceleration but no other signs of puberty - 6 years of age in boys and girls - rise in DHEAS, urine 17-ketosteroids (hydroxysteroids normal) - bone age on upper end of normal - more likely to develop PCOS or hyperandrogenism - ACTH stim test with 17-OHP (rule out atypical CAH)


What is Russel-Silver syndrome?

A growth disorder from before and after birth: LBW & FTT, normal head size Low appetites and at risk of hypoglycemia Small triangular face, prominent forehead, downturned corners of mouth Delayed development, learning disabilities


What type of growth are these curves showing?

Constitutional delay of growth and adolescence


What form of growth?

Familial or genetic short stature


What form of growth?

Primary nutritional or severe chronic illness


What form of growth?

Congenital GH deficiency :)


Name a possible syndrome associated with this type of growth



What is the calculation for expected height range in kids?

(based on parents)

(Mum's height + dad's height) +/- 13cm if boy/girl

divided by 2


Range calculated as +/- 10cm


What is the rate of growth in both sexes?

4-7 cm/year


When are kids 'allowed' to cross percentile lines on the growth chart?

1- within first three years of life while finding their fit (ie: small infants to large parents and vice versa)

2- at puberty (accounting to different start times of growth spurts)


What is IGF1?

Insulin like Growth Factor 1

factor produced by growth hormone's effect on the liver 


What is the significance of bone age? 

Where to measure?

Most conditions that cause poor linear growth also cause a delay in skeletal maturation and retarded bone age, it indicates that the short stature is to some extent reversible. 

A bone age that is NOT delayed is of greater concern and can be diagnostic ie: syndromes, achondroplasia, rickets


Measure at hand and wrist epiphyseal maturation centers


What investigations to consider in a well nourished child with a deceleration in linear growth?


bone age

karyotype if female


(if considering glucocorticoid excess: 24h urinary free cortisol & creatinine)


Approach to decelerating linear growth in a thin child?

Consider primary GI, nutritional, renal or other systemic chronic disease:





first morning void


What findings suggest growth hormone deficiency:

in the neonate? (try 4)

in the child? (try 3)

neonate: 1- hypoglycemia, 2- prolonged jaundice, 3- hepatitis, 4- microphallus, 5- traumatic delivery

child: 1- cranial irradiation, 2- head trauma or CNS infection, 3- cosanguinity or affected family member, 4- craniofacial midline abnormalities 


What growth findings would suggest GH deficiency?

severe short stature (< 3 SD below)

height < 2 SD and height velocity <1 SD



Indications for GH treatment approved by FDA

GH deficiency


Chronic Renal Failure

Idiopathic short stature

SGA with short stature

Prader Willi


Define central precocious puberty & tests to investigate

Onset of secondary sexual characteristics:

development on breasts before the age of 8 in girls

development of testicular volume >4mL before the age of  9 in boys


Order bone age, FSH/LH/estradiol/testosterone

If +ve, consider GnRH stim test and cranial imaging in boys or girls <6yo


Who do you worry more about with precocious puberty, girls or boys?


90% of girls have the idiopathic form

75% of boys will have a structural CNS abnormality


How do you treat central precocious puberty?

(assuming work-up negative)

GnRH agonist in order to disrupt pulsatility

ie: Leuprolide acetate (Lupron)

Actual adult height of patients followed is 1 SD less than mid-parental height


What is the most common form of congenital adrenal hyperplasia?

What lab findings?

'Salt-losing form' 70% of CAH

21-hydroxylase deficiency (90% of CAH cases) therefore accumulation of 17-OHP as it can't be converted to 11-deoxycorticosterone and 11-deoxycortisol (aldosterone and cortisol precursors)


Presents with hyponatremia, hyperkalemia, hypoglycemia, metabolic acidosis, vomiting, lethargy, shock at 10-14 days of age


When do virilized females with CAH get operated?

What to do with subsequent pregnancy in mum?

They get operated at 2-6 months.


Subsequent pregnancies can be treated with dexamethasone in order to suppress fetal androgen production and lessen external genitalia virilization. Once CVS can be done, continue treatment only if the fetus is a female. 


When do boys with 'simple virilizing' CAH generally present, and with what?

'Simple virilizing' form 30% of CAH

Often not diagnosed until 3-7 years of age when excess androgens have already caused accelerated linear growth +/- excessive muscular development, pubic and axillary hair, acne and deep voice, prepubertal testes (skeletal maturation up to 5 years in advance of chronological age, ends up with shorter adult height because of premature closure). 


Name the most common disorders of sexual differentiation

virilizing CAH (14%)

androgen insensitivity syndrome (10%)

mixed gonadal dysgenesis (8%)

clitoral / labial anomalies (7%)

hypogonadotropic hypogonadism (6%)

46 XY SGA with hypospadias (6%)


Suggested approach to abnormal sexual differentiation?

1) history and physical, ***palpable gonads

2) investigations:

a) karyotype

b) blood tests: 17OHP, androstenedione, gonadotropin levels, molecular testing for SRY

c) internal anatomy evaluation with US, endoscopic GU exam, VCUG, CT or MRI


Describe the pathophysiology, physical and lab findings of androgen insensitivity syndrome

mutation in androgen receptor gene, X-linked recessive, most common male DSD

phenotypic spectrum with complete AIS presenting as phenotypic females and normal appearing males with simply infertility

46X-Y, testes, normal or elevated LH and testosterone (&DHT) levels, vagina ends in blind pouch (no other female internal organs). At puberty breast development but no menstruation and no sexual hair. Adult height that of male XY. 

Replacement therapy with estrogens indicated at puberty. 


What are the features of Denys Drash syndrome?

WT1 gene mutation

Nephropathy, bilateral Wilms tumour, ambiguous genitalia in XY with undescended testes


What are parathyroid hormone's effects?

Symptoms of hypoparathyroidism?

In response to low serum calcium and high phosphate: PTH turns on and increases calcium, decreases phosphate. 


Symptoms related to hypocalcemia: MSK cramps and pain, numbness, Chvostek & Trousseau, convulsions, ICP/headache/papilledema, cataracts


When might you consider testosterone therapy in short boys?

Constitutional delay of growth and adolescence consider show term (4-8mo) low dose testosterone

- delayed onset of puberty, bone age >2 SD below mean

- weight and height decrease near the end of infancy, parallel the norm throughout childhood and accelerate towards the end of adolescence 

- parents height in normal and patient's expected adult height is normal


How can you distinguish between constitutional delay of growth and adolescence and familial short stature?

Bone age is normal in familial short stature whereas it is delayed in CDGA


95% of kids greater than two years of age have at least this growth velocity

4 cm/year


What features should be present before diagnosing benign premature thelarche in a toddler?

What findings on investigation?

1) Age <3y 2) Normal or slightly advanced bone age (with 2-3 years) 3) No other signs of precocious puberty (no estrogen changes in genitalia) 4) Persists for 3-5 years, not progressive


Detailed history reassuring, bone age with 2-3 yrs

LH/FSH/estradiol normal, no pelvic US necessary


What tests to order if you suspect peripheral precocious puberty?

LH, FSH levels

DHEAS, testosterone, 17-OHP, estradiol

Abdominal US, testicular US


What is premature pubarche?

Appearance of sexual hair before 8y in girls or 9y in boys without other evidence of sexual maturation



What random gluose threshold is used to diagnose diabetes?



When, how and how often should you test for type 2 diabetes?

Do a fasting plasma glucose every 2 years

1) if >3 in prepubertal or >2 in pubertal children: 

a) Overweight (BMI >95%)

b) High risk race (native, black, hispanic, asian, pacific islander)

c) Family history of DMII or hyperglycemia in utero

d) Signs or symptoms of insulin resistance (PCOS, HTN, acanthosis, dyslipidemia)

2) Use of an atypical antipsychotic

3) Impaired fasting glucose or impaired GTT 


How to differentiate between type 1 and type 2 DM?

1) Clinical presentation

2) History

3) Lab studies 

DM II are generally overweight, after puberty, signs of insulin resistance, family history, level of sugar in true DKA >50, ketoacids +++, 


What is the threshold for fasting blood glucose to diagnose diabetes?

>7 mmol/L


What A1C is considered a threshold for diagnosis diabetes?



What is first line treatment for DMII?


Side effects?

1) Metformin 

2) normal renal function (potentially fatal lactic adidosis reported) and normal hepatic function 

3) common side effects related to GI


What are typical insulin orders when a patient is NPO for surgery?

50% of usual NPH/Lente dose

no rapid

D5NS IVF at maintenance


What is the usual progression of puberty in girls and boys?

Girls: thelarche -> pubarche -> increased growth velocity -> menarche

Boys: testicular enlargement -> phallus enlargement -> adrenarche -> growth spurt


What tests should be ordered for a scrotal mass?


alpha-fetoprotein, B-HGC


What is considered delayed sexual development?

When is it considered primary amenorrhea?

Delayed sexual development: girls 13 or boys 14 years

Periods should come by 5 years since the beginning or puberty, or by 16 years. 


MALE Pubertal gynecomastia, describe the following:

- size?

- peak age or Tanner stage?

- tender?

- duration

- 0.5cm in diameter

- 14 yrs or Tanner 3-4 (testes 5-10mL)

- tenderness common

- spontaneous regression months-years (2 max)



Name 5 causes of pathological gynecomastia

1) Familial x-linked or AD gynecomastia

2) exogenous sources of estrogens ie meds like spironolactone

3) Klinefelter

4) Male undervirilization ie AIS

5) CAH

6) Leydig cell tumours

7) Prolactinoma

8) Hyperthyroidism



What are the diagnostic criteria of PCOS?

2 of the following:



Polycystic ovaries


In who is soy formula especially contraindicated?

Congenital hypothyroidism, the phytoestrogens can inhibit thyroid peroxidase so thyroxine levels should be monitored more closely


What are features of Klinefelters?

47 XXY

psychiatric (LDs, anxiety)

tall & slim with legs>>arms

failure of testicular growth, small phallus (hypergonadotropic hypogonadism)

delayed puberty


increased risk breast cancer, germ cell tumours, leukemia, lymphoma


Major etiologies of congenital hypothyroidism?

Thyroid dysgenesis (aplasia, hypoplasia, ectopic gland) 80-85%

Inborn error of thyroxine synthesis (dyshormonogenesis) 15%

Maternal thyrotropin-receptor blocking antibodies 2%

mostly sporadic cases, rarely familial but has been described



Clinical findings in congenital hypothyroidism


prolonged physiologic jaundice

feeding difficulties

large tongue

sluggish, poor appetite, increased sleep


umbilical hernia

cold and mottled

edema of genitals and extremities

pulse slow, cardiomegaly, pericardial effusion

macrocytic anemia

widely open anterior and posterior fontanelles

mental retardation

retardation of osseous development on x-rays


What are clinical manifestations of neonatal graves? Early and late

Early: restless, irritable, hyperactive, exophthalmos, tachycardia, tachypnea, temperature elevation

Later: weight loss, ravenous appetite, HSM, jaundice, HTN, cardiac decompensation

Late: advanced bone age, frontal bossing, craniosynostosis 


Treatment of neonatal Graves?





How to confirm diabetes insipidus on labs?

Serum osm >290 mOsm/kg

Urine osm <290 mOsm/kg


Unlikely if SOsm <270 or UOsm >600


What are the features of McCune Albright?

Cutaneous pigmentation (Coast of Maine cafe au lait)

Fibrous dysplasia



Name side effects anabolic steroids

boys: decreased sperm count, testicular atrophy

girls: menstrual irregularities, virilization

hepatic problems (transaminitis, cholestatic jaundice, hepatitis, HCC)

psychological effects (agression, anxiety, paranoia...)



What is the approach to congenital hypothyroidism?

See patient

Repeat labs

Treat while awaiting result


What is the beta-HCG stimulation test used for?

Differentiating 5 alpha reductase deficiency, CAH and ovotesticular DSD:

if no testes: no rise in testosterone or DHT

if partial androgen insensitivity: rise in both testosterone and DHT

if 5 alpha reductase deficiency: rise in testosterone but not DHT (T:DHT ratio high! >12)


What is the most common form of childhood hypoglycemia? 


ketotic hypoglycemia, usually related to substrate issue (with intercurrent illness and decreased food intake)

hypoglycemia + ketonemia + low plasma insulin concentrations

when sick screen for ketones, ensure high protein & high carbohydrate diet


What can cause a false positive neonatal thyroid screen?


non-thyroidal illness

TBG deficiency

test done too early (within 24-48h of birth)


What can cause false negative congenital hypothyroidism screen?

prematurity + low birth weight

critically ill



What is the management of a positive neonatal hypothyroidism screen?

Call the patient in

History and physical exam

Repeat labs (TSH T4 TBG TRAbs)

Start therapy


Radionuclide uptake scan

Urinary iodide


What type of rickets?

low 25-OHD, hyperPTH

Vitamin D deficiency 


What kind of rickets?

high PO4, hyperPTH, low1-25OH vitD

Chronic kidney disease


What regulates 1-alpha hydroxylase?


upregulated by PTH and hypophosphatemia

downregulated by hyperphosphatemia and 1-25D


What is the best method to screen for diabetic nephropathy?

What to do if it is positive?

Screen with spot urine albumin to creatinine ratio

Abnormal results should be confirmed at least 1 month later with FIRST morning albumin to creatinine ratio or timed, overnight urine collection for albumin excretion rate


When do you send diabetics for ophthalmology screening?

T1DM: if >/= 15,  annually, starting 5 years after the onset of diabetes. Can stretch q2yrs if good control, sick <10yrs, no abN to follow up

screen for thyroid and celiac in T1DM at diagnosis!

T2DM: immediately after diagnosis


What are risk factors for cerebral edema in DKA?

1) <5 years old

2) newly diagnosed disease

3) severe acidosis (pH <7.1)

4) low pCO2

5) high BUN

6) bicarbonate treatment

7) administration of insulin in 1st hour

8) greater volumes of fluid given in first 4 hours

9) attenuated rises in serum sodium during therapy


How do you calculate an insulin sensitivity factor?

ISF: 100 divided by total daily insulin intake (long and short acting)

ie: if 13 units long active, 12 units short acting, ISF=100/25=4 so giving one unit of insulin would drop the blood sugar 4


Name three rapid insulins





Name three long acting insulins


Insulin Glargine

Insulin Detemir 


What are the target HA1C in:

1) DMII 

2) DM1 in <6yo

3) DM1 in 6-12yo

4) DM1 in >12yo

1) type 2 diabetes should be ≤7.0%

2) in <6yo A1C <8%

3) in 6-12yo A1C= 7.5%

4) in >12yo HA1C =7%


How do you manage a severely hypoglycemia child at home?

Glucagon 1mg IM

if in hospital dextrose 0.5-1g/kg IV over 1-3 minutes 


In a patient in DKA with shock, describe management 

IVF isotonic fluids just to correct circulatory inadequacy

IV infusion insulin 0.1 units/kg/hour minimum 1hr after fluid therapy begun

add glucose to IVF once plasma glucose 14-17mmol/L

avoid sodium bicarbonate 


When do you start screening for microalbuminuria?

>/= 12 years old


Name infantile effects of maternal diabetes

1) sacral agenesis 2) congenital heart disease 3) small left colon syndrome 4) polycythemia (renal vein thrombosis) 5) hypoglycemia