CMPP: Hypercalcemia

primary hyperparathyroidism

familial hypocalciuric hypercalcemia (FHH)

what are some parathyroid mediated causes of hypercalcemia

malignancy

elevated vitamin D

granulomatous disease

medication

milk-alkali syndrome

immobilization

parenteral nutrition

hyperthyroidism

what are some non-parathyroid mediated causes of hypercalcemia

stones, bones, abdominal groans, and psychiatric overtones

what is the memory trick associated with knowing the symptoms of hypercalcemia?

bone pain secondary to increased osteoclastic activity, osteoporosis, osteomalacia, fractures, arthritis

what are the bone symptoms associated with hypercalcemia?

anorexia, nausea, constipation, pancreatitis, PUD, polyuria, polydipsia

what are the abdominal symptoms associated with hypercalcemia?

varies from anxiety and depression to lethargy and coma

what are the psychiatric symptoms associated with hypercalcemia?

PTH, ionized calcium, phosphorus, renal functions, Vitamin D (25-Oh vs 1,25OH depending on GFR)

first line lab evaluation for hypercalcemia

24 hour urine for calcium excretion

DEXA scan

second line lab tests for hypercalcemia

adenoma of the parathyroid gland - most common

hyperplasia of the parathyroid glands

parathyroid carcinoma

causes of primary hyperparathyroidism

PTH: elevated or upper normal

Calcium: total and ionized are elevated

Phosphorus: low or low normal

Urinary excretion of calcium: typically elevated

lab values associated with primary hyperparathyroidism

localize hyper functioning parathyroid tissue -- less valuable with coexisting thyroid disease

purpose of a SPECT scan in primary hyperparathyroidism

different isotopes taken up by parathyroid/thyroid

purpose of a dual isotope scintigraphy in primary hyperparathyroidism

can try to visualize glands -- operator dependent and difficult with coexisting thyroid disease

purpose of a neck ultrasound in primary hyperparathyroidism

thyroid nodule

if one with primary hyperparathyroidism has a palpable node on exam, it is most likely a...

Osteitis fibrosa cystica

chronic PTH excess alters bone; increased osteoclastic activity secondary to increased PTH; creates and increase in calcium and alkaline phosphatase

bone pain, fractures, swelling, deformities

symptoms of Osteitis fibrosa cystica

brown tumors, subperiosteal reabsorption, skill with salt and pepper appearance, loss of enamel on the teeth

imaging findings associated with Osteitis fibrosa cystica

Brown tumors

areas of demineralization; bone cysts

distal phalanges; tapering of clavicles

in Osteitis fibrosa cystica, subperiosteal reabsorption occurs at the...

limite dietary calcium to 800-1000 mg daily

encourage physical activity to encourage bone formation

increase fluid to reduce kidney stones

maintain vitamin D 25-OH level 20-30

avoid meds that increase calcium

follow ionized calcium PTH, and Cr

bone density screening every 1-2 years

how to monitor primary hyperparathyroidism (older than 50 with serum calcium <12 mg/dL)

thiazide diuretics, lithium

what meds that increase calcium

bisphosphonates (inhibitor of bone resorption)

Cinacalcet (Sensipar)

medical tx for primary hyperparathyroidism

activates calcium sensor on parathyroid glands, leading to inhibitor and blocking PTH release

must monitor calcium closely

Cinacalcet (Sensipar) MOA

symptomatic

age <50

serum calcium >12 mg/dL, 24 hr urine excretion >400 mg/dL

T score -2.5

Pancreatitis, PUD, GERD

indications for surgical tx of hyperparathyroidism

Parathyroidectomy

surgical removal of 3.5 glands that involves intraoperative PTH monitoring; hopefully leaving enough to prevent hypocalcemia

ionized calcium and PTH -- esp POD 1-2 --> hungry bone syndrome

what must be monitored after parathyroidectomies?

Familial hypocalciuric hypercalcemia (FHH)

autosomal dominant defect in CaSR gene that is responsible for urinary calcium excretion

elevated calcium and magnesium, normal/mildly elevated PTH, HYPOCALCIURIA

fractional excretion of Ca is often <1%

what are some lab values associated with FHH?

malignancy (metastatic lesions to bone cause release of skeletal Ca)

what is the second most common cause of hypercalcemia?

PTH related protein (PTHrP)

some malignancies secrete...

PTH level

malignancies are characterized by a normal...

primary bone, squamous cell cancer (lung/esophageal), multiple myeloma, less likely with lymphoma, leukemia

what are some malignancies associated with hypercalcemia?

Prostate, thyroid, breast, lung, kidney

what solid tumors metastasize to the bone?

too much vitamin D cause increase in intestinal absorption of calcium

how does vitamin D toxicity cause hypercalcemia?

hypercalcemia/kidney stones

weakness, headache, polyuria, metallic taste

presentation of one with vitamin D toxicity

stop all supplementation

may use glucocorticoids in severe toxicity

treatment for vitamin D toxicity

blocks sodium resorption at the expense of retaining calcium (mild)

how can thiazide diuretics cause hypercalcemia?

decreases parathyroid gland sensitivity to calcium

reduces renal excretion of calcium

how can lithium cause hypercalcemia?

sarcoidosis and tuberculosis

what granulomatous diseases cause hypercalcemia?

they synthesize vitamin D 1,25-OH

how do granulomas cause hypercalcemia?

low PTH levels, high calcium, high vitamin D 1,25 OH

what are the lab findings seen with granulomatous diseases?

thyroid hormone has some direct bone reabsorbing property (osteoclastic like activity)

how does hyperthyroidism cause hypercalcemia?

PTH levels are low but phosphorus levels are elevated

calcium levels associated with hyperthyroidism

high rate of bone resorption -- leads to hypercalcemia/hypercalciuria

how does immobilization cause hypercalcemia?

with pre-existing high turn over rate

--> teens, paget's disease of bone, thyrotoxicosis

hypercalcemia due to immobilization is usually sene in patients...

Milk-alkali syndrome

triad of hypercalcemia, metabolic alkalosis, and renal insufficiency; ingestion of >2g elemental calcium daily with ab absorbable alkali

triad of hypercalcemia, metabolic alkalosis, and renal insufficiency

triad associated with milk-alkali syndrome

elevated serum calcium, may have slight decreased PTH, decreased phosphorus

--> leads to increased bicarb reabsorption and alkalosis --> enhances calcium reabsorption and makes hypercalcemia worse

lab values associated with milk-alkali syndrome

the elderly with underlying kidney disease

milk-alkali syndrome is typically seen in...

restore renal perfusion (saline diuresis)

Increase calcium excretion (loop diuretics)

decrease skeletal resorption (bisphosphonates)

treatment for hypercalcemia if one's calcium is 13-15 with altered mental status