Endocrinology Flashcards
Normal delay between bone age and chronological age
2 years
Genetic/Familial Short Stature
- Born with normal length, but height then decelerates over first 2 years of life to find new genetically determined curve
- Bone age MATCHES chronological age
- Proportional in height and weight
Mid-parental height equation
- [Dad’s height + Mom’s height +/- 5 inches or 13 cm]/2
- Add length for boys, subtract for girls
Constitutional growth delay
- Normal growth until about 1 year, then around 3rd - 5th percentile (usually NOT below 3rd percentile)
- Height matches with bone age films
- DELAYED BONE AGE + DELAYED PUBERTY (pt still has to hit puberty and will continue to grow)
- GH NOT indicated UNLESS >2.25 SD below mean (< 1.2%)
- May consider referral to Endo for short course of testosterone due to psychosocial factors
Short Stature 2/2 Growth Hormone Deficiency
- RARE
- PE: micropenis, small clitoris, hypoglycemia (look for seizures in hx)
- DECELERATED growth rate - lines on growth chart crossed
- Dx: lack of GF release following stimulation with insulin or arginine
Congenital GH deficiency
- Bone age approx. 75% of chronologic age + DECELERATED GROWTH RATE + weight percentile > height percentile (remember w/ constitutional delay, wt/ht will be similar)
- Typically NOT the answer on boards
Acquired GH deficiency
- Delayed bone age and SHARPLY DECELERATED growth rate
- MUST refer to Endocrinology and obtain MRI to evaluated for CNS tumor
Metabolic Syndrome
- Truncal obesity
- Low HDL
- High triglycerides
- High BP
- FBG > 100 mg/dL
- Acanthosis nigricans is NOT part of definition
Diagnosis of Diabetes Mellitus
- Fasting blood glucose > 125 mg/dL
- 2 hours plasma glucose tolerance test >/= 140 = prediabetes; >/= 200 = DM.
- Hgb A1C >/= 5.7% prediabetes; >/= 6.5% DM
Differentiating central vs peripheral precocious puberty in males
- Central = testicular volume increased AND/OR LH >/= 0.3 IU/L
- Also may see increased testicular volume with hCG secreting tumors, though volumes usually smaller than expected for other pubertal signs
Peripheral precocious puberty causes
- May originate from arenal gland, gonad, an hCG-secreting tumor (in boys), exogenous hormone exposure, or severe hypothyroidism.
- Testicular volume will be prepubertal (with exception of hCG secreting tumor) and LH will be in prepubertal range (< 0.3 IU/L).
Hashimoto thyroiditis
- Most common cause of hypothyroidism and goiter in children
- AI destruction of thyroid gland
- Thyroid function may be normal, though at risk of hypothyroidism in the future
- Thyroid enlarged, firm, rubbery and heterogenous
Thyroid exam in Hasimoto’s vs Grave’s
- Hashimoto’s = enlarged, firm, rubbery, heterogenous
- Grave’s = larger, less firm and more homogenous
Thyroxine-binding globulin deficiency
- X-linked disease
- NBS reveals normal TSH but LOW T4. NBS measures T4 (bound hormone) -> due to def of binding globulin, T4 is low.
- Check FREE T4 (normal) or TBG
- If TSH is normal –> NO treatment is needed
Signs of congenital hypothyroidism
- May be asymptomatic at birth due to maternal thyroxine crossing placenta
- Puffiness, large tongue, hoarse cry, umbilical hernia, hypotonia, large anterior fontanelle, open posterior fontanelle, constipation, mottling