Endocrinology Flashcards
1
Q
Normal delay between bone age and chronological age
A
2 years
2
Q
Genetic/Familial Short Stature
A
- 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
3
Q
Mid-parental height equation
A
- [Dad’s height + Mom’s height +/- 5 inches or 13 cm]/2
- Add length for boys, subtract for girls
4
Q
Constitutional growth delay
A
- 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
5
Q
Short Stature 2/2 Growth Hormone Deficiency
A
- 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
6
Q
Congenital GH deficiency
A
- 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
7
Q
Acquired GH deficiency
A
- Delayed bone age and SHARPLY DECELERATED growth rate
- MUST refer to Endocrinology and obtain MRI to evaluated for CNS tumor
8
Q
Metabolic Syndrome
A
- Truncal obesity
- Low HDL
- High triglycerides
- High BP
- FBG > 100 mg/dL
- Acanthosis nigricans is NOT part of definition
9
Q
Diagnosis of Diabetes Mellitus
A
- Fasting blood glucose > 125 mg/dL
- 2 hours plasma glucose tolerance test >/= 140 = prediabetes; >/= 200 = DM.
- Hgb A1C >/= 5.7% prediabetes; >/= 6.5% DM
10
Q
Differentiating central vs peripheral precocious puberty in males
A
- 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
11
Q
Peripheral precocious puberty causes
A
- 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).
12
Q
Hashimoto thyroiditis
A
- 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
13
Q
Thyroid exam in Hasimoto’s vs Grave’s
A
- Hashimoto’s = enlarged, firm, rubbery, heterogenous
- Grave’s = larger, less firm and more homogenous
14
Q
Thyroxine-binding globulin deficiency
A
- 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
15
Q
Signs of congenital hypothyroidism
A
- 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
16
Q
Most common causes of hypothyroidism
A
- Dysgensis is MOST COMMON
- Abnormal thyroid development between base of tongue and normal position - mass is midline, though not cystic
- Acquired hypothyroidism
- Hashimoto thyroiditis
17
Q
Management of abnormal TSH on NBS
A
- Start levothyroxine and order TSH and fT4
- Cognitive delays may occur if thyroid hormone is not supplied by 2 weeks of age
- May DC meds later if labs normal
18
Q
Labs with Hashimoto thyroiditis
A
- anti-TPO
- anti-thyroglobulin
- low fT4
- elevated TSH
19
Q
Most specific marker of adrenal androgen production
A
- DHEA-S is more specific than testosterone
20
Q
Neonatal Graves Disease
A
- Maternal thyroid-stimulating antibodies cross placenta. Even if Mom tx with RI ablation, antibodies remain. Mom may be on levothyroxine due to RI ablation.
- Symptoms present in IMMEDIATE newborn period
- S/S: tremors, tachycardia, SVT, increased Moro, very alert/awake). May lead to heart failure!!
- Diagnose with thyroid function panel
- Tx: methimazole and a β-blocker for a few months until the maternal thyroid-stimulating antibodies wane
- Of note, maternal levothyroxine has minimal effect on fetus
21
Q
Best laboratory indicator of vitamin D status
A
- 25-hydroxy vitamin D
22
Q
Effect of prolonged immobilization on calcium
A
- Causes increased calcium
- Increased calcium may lead to inhibition of vasopressin (ADH) –> polyuria, polydipsia, HA, nausea and abdominal pain
- Dx with iCa
- Tx with saline diuresis and loop diuretics
23
Q
Definition of hypercalcemia
A
- Calcium > 12
24
Q
Effects of hypercalcemia
A
- Shortening of ST segment –> shortened QT interval
- S/S: Bones, stones, groans and moans: Bones (osteoporosis, osteomalacia, pathologic fx, osteitis fibrosis cystica), Stones (nephrolithiasis, nephrocalcinosis, nephrogenic DI), Groans (N/V, constipation, abdominal pain, Moans (coma, delirium, depression, fatigue, psychosis), polyuria, polydipsia, HA
- Tx with IV hydration. If due to immobilization, tx with loop diuretics (due to inhibition of calcium reabsorption in thick ascending limb).
25
Causes of hypercalcemia
- Familial hypocalciuric hypercalcemia - benign.
- Williams Syndrome
- Vitamin D ingestion
- Vitamin A ingestion
- Thiazide diuretics (calcium sparing)
- Skeletal disorders (i.e. dysplasias, skeletal immobilization, skeletal/body casting)
- Hyperparathyroidism
- Malignancy
