Endocrine Flashcards
Calcium levels during prolonged immobilization
Elevated
(due to increased osteoclastic bone resorption)
Immobilization can cause ____ due to increased osteoclastic bone resorption
Hypercalcemia
(Tx: Bisphosphonates)
Inhibit osteoclastic resorption, reducing bone loss
Bisphosphonates
Proximal myopathy in Cushing syndrome (hypercortisolism) is due to
Muscle atrophy
(from direct catabolic effects of cortisol on skeletal muscle)
___ in transfused blood binds ionized calcium
Citrate
(causes symptomatic hypocalcemia by affecting ionized calcium only)
Calcium after high-volume blood transfusion
Hypocalcemia
due to citrate-chelation of ionized calcium
Magnesium abnormality in hyperreflexia
Hypomagnesemia
Young woman with new-onset absence of menses, next step
Secondary amenorrhea w/u:
- Pregnancy Test (beta-hCG)
- Prolactin, TSH, FSH to test for most common causes of secondary amenorrhea
- Hyperprolactinemia
- Thyroid dysfunction
- Premature ovarian failure (early menopause)
Hyperandrogenism presenting in non-obese adolescent
CAH: 21-hydroxylase deficiency
(elevated 17-hydroxyprogesterone)
Estrogen/Pregnancy & Thyroid Function
Estrogen increases TBG, necessitating increased endogenous thyroid production or increased levothyroxine dosing requirements in hypothyroid pts to achieve same level of free T4.
Prolonged glucocorticoid therapy can lead to
Central adrenal insufficiency (low [suppressed] ACTH secretion, low cortisol, normal aldosterone due to regulation by RAAS, not HPA axis)
Best markers to track resolution of DKA
Serum anion gap or beta-hydroxybutyrate levels
AG estimates unmeasured anion concentration in blood & returns to nml w/ disappearance of ketoacid anions
Enlarged hands and feet
Acromegaly
(excessive GH secretion from pituitary somatotroph adenoma)
- +Coarsening facial features
- +OSA
- +Concentric LVH
Leading cause of death in acromegaly pts
Cardiovascular disease
Ease of bruising + hyperglycemia
Think Cushing syndrome
(hypercortisolism)
HTN + Hypokalemia vs. Hypotension + Hyperkalemia
Primary Hyperaldosteronism vs. Primary Adrenal Insufficiency (Addison Disease) respectively
- Hyperaldo β HTN, Na+ reabsorption, K+ loss
- PAI β Low aldosterone: Decreased Na+ reabsorption, increased K+
Hyperglycemia in Cushing is due to
Hypercortisolism-induced gluconeogenesis (physiological stress response)
Hypernatremia + increased serum Osm
Diabetes Insipidus
(central vs. nephrogenic): Too low ADH
Necrotic migratory erythema rash (w/ central clearing in thighs)
Glucagonoma
(+ hyperglycemia)
Predisposition in pts with Hashimoto
Thyroid lymphoma
(presents w/ rapidly progressive thyroid enlargement)
Wt gain, psychiatric sx, hirsutism, HTN, hyperglycemia
Hypercortisolism
(Cushing syndrome)
- Dx: Low THen High
Most common cause of primary adrenal insufficiency in developed countries
Autoimmune adrenalitis
(Addison disease)
- Associated w/ other autoimmune diseases, e.g. Hashimoto Thyroiditis
Plaques w/ central clearing & blistering; crusting & scaling at borders
Necrolytic migratory erythema
(Glucagonoma)
- Usually in the thighs
Pancreatic tumor w/ elevated glucagon levels (>500)
Glucagonoma
5-HIAA
Carcinoid syndrome diagnosis
Anti-Glutamic Acid Decarboxylase Antibody
(Anti-GAD65)
Serum marker for T1DM predisposition
(pancreatic islet autoantibodies)
Palliation of anorexia to improve appetite & wt gain in cancer-related anorexia/cachexia syndrome
Progesterone analogs
(Megestrol acetate orβ Medroxyprogesterone acetate)
Diabetic w/ low blood sugars after meals
Diabetic Gastroparesis
(give metoclopramide)
Diabetic w/ early satiety
Gastroparesis
(2/2 diabetic autonomic neuropathy of the GI tract)
- Tx: Metoclopramide
Severe hyperglycemia (>1000) without acidosis
HHS
(Hyperosmolar Hyperglycemic State)
- Tx: IVF (Normal Saline) + slow IV Insulin
Hypercalcemia + Lymphoma
Due to increased 1,25-VitD from extrarenal production
(also seen in sarcoidosis)
Parathyroid Hormone-related Protein
Think Cancer-related hypercalcemia
(mimics PTH):
- SCC of lung, renal/bladder, or breast/ovarian cancer
- Released by SCC of lung, causing Humoral Hypercalcemia of Malignancy
Severe, rapid-onset hypercalcemia + hypophosphatemia + smoker
Humoral Hypercalcemia of Malignancy
(SCC of the lung) due to release of parathyroid hormone-related protein (PTHrP) by tumor cells
Low T3, Normal T4, Normal TSH
Euthyroid sick syndrome
(usually in setting of acute, severe illness)
Riedelβs Thyroiditis
Fibrous thyroiditis
(Fibrosclerosis of thyroid causing hard goiter + hypothyroidism)
Euthyroid sick syndrome
βLow T3 syndromeβ:
Decreased peripheral 5β-deiodination of T4 due to caloric deprivation in setting of acute, severe illness
Pt w/ fever + sore throat within 90d of starting antithyroid drugs (propylthiouracil or methimazole)
DISCONTINUE PTU or MMI and check WBCs (agranulocytosis is a feared but uncommon side effect)
Does primary hyperaldosterone cause peripheral edema?
Not significantly, due to aldosterone escape
Tx for BL adrenal hyperplasia
MRAs
(aldosterone antagonists): Spironolactone, Eplerenone
Recurrent pregnancy loss + thyroid disease
Antithyroid peroxidase antibodies
(Hashimoto Thyroiditis; Anti-TPO Abs)
Hyperpigmentation
think high ACTH
(Cushing vs. ectopic ACTH-producing tumor)
Easy bruising, myopathy, virilization, lanugo hair
Cushing syndrome
Dx of Primary Adrenal Insufficiency
ACTH Stimulation Test
(then cortisol and aldosterone measured)
Tx of Primary Adrenal Insufficiency
(Addisonβs disease)
Cortisol, Aldosterone, and Testosterone
Cravings for salty foods, N/V, fatigue, dizziness, syncopal episodes, hypovolemia
Primary adrenal insufficiency
- Low aldosterone - hyponatremia, hypovolemia, hyperkalemia
- Low cortisol - Elevated ACTH, hyperpigmentation
- Low adrenal-produced testosterone - decreased sex drive in women
Hyperpigmentation + fatigue + dizziness
Primary adrenal insufficiency
(elevated ACTH due to low adrenal production of cortisol)
Addisonian Crisis
Acute primary adrenal insufficiency
(injury, surgery, infection)
- Sudden pain in back, abd, or legs
- Dehydration from Vomiting, Diarrhea
- Syncope from Low BP
- Can be fatal
Waterhouse-Friderichsen Syndrome
Acute adrenal insufficiency when sudden increase in BP causes blood vessels in adrenal cortex to rupture β> ischemia, adrenal gland failure
Multiple gastric ulcers + dyspepsia
Gastrinoma
(ZES)
VIPoma
(pancreatic tail tumor) Tx
- IVF (volume repletion)
- Octreotide (for diarrhea)
- Surgical resection
Watery diarrhea, hypokalemia, achlorhydria, facial flushing & pancreatic tail tumor
VIPoma
(Tx: Surgical)
*
HTN, hyperglycemia, weight gain, proximal muscle weakness
Cushing syndrome
(Hypercortisolism)
- Exogenous glucocorticoid intake
- SCLC (ectopic ACTH)
- Pituitary adenoma (Cushing disease [ACTH-producing])
Galactorrhea + amenorrhea + vaginal dryness
Prolactinoma
(dryness due to prolactin inhibition of LH secretion)
Basal ganglia lesion
Parkinson disease
Difficulty combing hair
Proximal muscle weakness
- Polymyositis/Dermatomyositis (normal DTRs)
- Glucocorticoid use/Cushing disease
- Hypothyroidism/Hyperthyroidism
MG/Lambert-Eaton syndrome Basal ganglia lesion
Parkinson disease
Effects of CKD on Ca, Phos, VitD
Inadequate phosphate excretion, decreased conversion to 1,25-hydroxyvitamin D
(Elevated Phos, Low Ca, Elevated PTH, Low active VitD)
Positive sx in diabetic neuropathy
(pain, paresthesias)
Small nerve fiber neuropathy
(early)
Negative sx in diabetic neuropathy
(sensory loss)
Large nerve fiber neuropathy
(late; leads to foot ulcers)
Anti-thyroid peroxidase antibodies
Hashimoto thyroiditis vs. Painless
(silent) thyroiditis
Tx for painless
(silent) thyroiditis
Self-limited
(BBs for symptoms)
RET proto-oncogene mutation
MEN2A or 2B
(MPP, MPM)
Neuroendocrine parafollicular C cell malignancy
Medullary thyroid cancer
(Calcitonin-producing tumor)
MEN1
- Primary hyperParathyroidism
- Pituitary tumors
- Pancreatic tumors (or gastrinomas)
MEN2A
- Medullary Thyroid Cancer (calcitonin)
- Parathyroid hyperplasia
- Pheochromocytoma
MEN2B
- Medullary Thyroid Cancer (calcitonin)
- Pheochromocytoma
- Mucosal neuromas/Marfanoid habitus
Diuretics that increase calcium resorption
Thiazides
Polyuria, polydipsia, shortening of QT interval
Hypercalcemia
(symptomatic)
Symptomatic hypercalcemia and AKI from excessive calcium intake
Milk-Alkali Syndrome
(often seen in OTC-treated osteoporosis)
Thyroid storm is often triggered by
- Surgery
- Trauma
- Infection
- Iodine Contrast
- Childbirth
Lid lag + normal reflexes
Hyperthyroidism
Lid lag + absent reflexes
Hypothyroidism
Malignant hyperthermia tx
Dantrolene
T cell activation and stimulation of orbital fibroblasts
Graves Ophthalmopathy
(TRAB-induced)
Autoantibodies against ACh receptors
Myasthenia Gravis
(on the motor endplate)
Increases sensitivity to catecholamines
Thyroid hormone
Acid/Base in hyperaldosteronism
Metabolic alkalosis
(due to aldosterone-induced H+ loss)
Increased aldosterone, decreased renin
Primary Hyperaldosteronism
(Presents w/ HTN + hypokalemia)
- Aldosterone-producing tumor, or
- BL adrenal hyperplasia
PCOS increases risk for
Metabolic syndrome
- T2DM
- HTN
- Dyslipidemia
Dx of Carcinoid Syndrome
Elevated 24hr urinary 5-HIAA
Tx for Carcinoid Syndrome
Octreotide
Carcinoid cells cause increased production of serotonin from tryptophan, resulting in ____ deficiency
Niacin
(tryptophan is required for niacin synthesis) β> Pellagra (dermatitis, diarrhea, dementia)
At risk for autoimmune thyroid disease
(e.g. Graves)
T1DM
Marfanoid habitus + thyroid cancer
MEN2B