Disorders Of Serum Minerals

Question 1

Ca above………….. are symptomatic

Answer 1

13 mg/dL

Question 2

Differential Diagnosis

Answer 2

Hyperproteinemia
• Parathyroid hormone–related hypercalcemia
– Primary hyperparathyroidism
– Tertiary hyperparathyroidism
– Familial hypocalciuric hypercalcemia
• Non parathyroid hormone–mediated hypercalcemia
– Malignancy-associated hypercalcemia (PTHrP)
– Granulomatous diseases
– Milk-Alkali syndrome
– Hyperthyroidism, Parenteral nutrition, Immobilization,meditations.

Question 3

Renal impairment due to hypercalcemia

Answer 3

• Afferent arteriolar vasoconstriction&raquo_space; ↓GFR,
• Diabetes insipidus

Question 4

Cardiac impairment due to hypercalcemia

Answer 4

Shortening of the QTc interval, widened QRS, bradycardia

Question 5

Hyperparathyroidism
• Primary hyperparathyroidism:
• Secondary hyperparathyroidism:
• Tertiary hyperparathyroidism:

Answer 5

85% single parathyroid adenoma

vitamin D deficiency, calcium deficiency, or chronic kidney disease

chronic renal failure

Question 6

Primary para hyperparathyroidism

Answer 6

• Asymptomatic
➢ Osteoporosis, bone pain, nephrolithiasis,
– BMD is relatively preserved at the spine, lower at the hip, particularly low at the
⅓ radius. (This is because the ⅓ radius is a predominantly cortical.)

• Classic skeletal manifestations: osteitis fibrosa cystica , brown tumors

Question 7

Familial hypocalciuric hypercalcemia (FHH):

Answer 7

*Autosomal dominant
* inactivating mutations of the calcium sensing receptor (CaSR)at PTH

• Hypercalcemia is typically mild, in the range of 11 to 12 mg/dL

➢ Abnormal calcium receptors are also expressed in the kidney

• Asymptomatic, Do not develop adverse sequelae

• homozygous patients usually develop severe hypercalcemia in infancy

Question 8

Malignancy-associated hypercalcemia
=A Non-PTH-mediated hypercalcemia

Answer 8

Among hospitalized patients (in known advanced malignancy)

• Approximately 50% of patients die within 30 days of developing malignancy-
associated hypercalcemia
• Tumors that commonly cause hypercalcemia include breast, renal, squamous cell,
ovarian carcinomas, multiple myeloma, and lymphoma

Question 9

Malignancy-associated hypercalcemia
=A Non-PTH-mediated hypercalcemia

Answer 9

1. Humoral hypercalcemia of malignancy (HHM) (~ 80% )
2. local tumor invasion of the skeleton
3. 1α-hydroxylase enzyme

Question 10

Humoral hypercalcemia of malignancy (HHM) (~ 80% )

Answer 10

Results from excessive secretion of parathyroid hormone–related protein (PTHrP)

• PTHrP acts on the same receptor as PTH and can induce similar systemic effects.

• Reductions in the levels of PTH, 1,25-dihydroxyvitamin D3, and serum phosphorus

Question 11

local tumor invasion of the skeleton

Answer 11

Breast cancer or a hematologic neoplasm such as multiple myeloma, leukemia, or lymphoma.

• Local factors secreted: PTHrP, RANKL, interleukin-6, …

• Hypercalcemia, hyperphosphatemia, ↓ PTH, ↓ PTHrP and ↓ 1,25(OH)2D

Question 12

1α-hydroxylase enzyme

Answer 12

Secretion of 1,25(OH)2D by lymphomas and dysgerminomas.

• The increased 1,25(OH)2D leads to intestinal calcium hyperabsorption as well as
bone resorption.

• This condition is mechanistically similar to the hypercalcemia that occurs in
granulomatous disease

Question 13

Granulommatous disease

Answer 13

including sarcoidosis, tuberculosis, and fungal infections
➢ 1α-hydroxylase enzyme
• hypercalcemia and hyperphosphatemia

Question 14

Milk-Alkali syndrome

Answer 14

Ingestion of very large quantities of calcium carbonate or other calcium-containing
antacids
• Triad of hypercalcemia, metabolic alkalosis, and acute kidney injury
• Calcium intake in patients typically exceeds 4 g/day

Question 15

• Drugs that may cause hypercalcemia include

Answer 15

Thiazide diuretics
lithium
Vitamins D

Question 16

Treatment of hypercealcemia due to overproduction of 1,25-vitamin D
related to granulomatous disease or lymphomas or dysgerminomas

Answer 16

Glucocorticoids

Question 17

Indications for Symptomatic primary HPT parathyroidectomy

Answer 17

kidney stones, reduced renal function.

serum calcium concentration greater than 1 mg/dL above normal.

Question 18

The initial treatment of hypercalceamia

Answer 18

1. intravenous hydration with isotonic solution
2. calcitonin SC /has a rapid onset of action, cause tachyphylaxis, should be discontinued after 24 to 48 hours.
3. antiresorptive agents like bisphosphonates or denosumab.

• Loop diuretics should be avoided unless patients have volume overload or heart failure.

Question 19

Hypoparathyroidism due to autoimmune polyglandular syndrome, where it can be
associated with

Answer 19

primary adrenal insufficiency (Addison’s disease)
mucocutaneous candidiasis
type 1 diabetes
autoimmune thyroid disease
vitiligo

Question 20

Hypocalceamia caused by hypoparathyroidism

Answer 20

Low serumPTH, hypocalcemia, phosphorus high normal or frankly elevated, reduced 1,25(OH)2D

• Asymptomatic basal ganglia calcification

• Treatment: large doses of calcium+active vitamin D (1,25[OH]2D)

• Adjunctive treatment; Thiazide diuretic
• Recombinant PTH 1-84

Question 21

Pseudo hypoparathyroidism
مستويات الپاراثورمون طبيعية أو عالية ولكن يتم مقاومة وظيفتها

Most common type?

Answer 21

end-organ resistance to PTH at the proximal tubules

Albright hereditary osteodystrophy or Pseudohypoparathyroidism Type Ia, is associated with resistance to multiple hormones.

Classic phenotype: short stature, shortened fourth and fifth
metacarpals and metatarsals, obesity, mental retardation,
subcutaneous calcifications, and café au lait spots

Action of PTH is preserved at DCT

Question 22

Long-term, high-dose treatment with older antiseizure medications such as
……………may lead to hypocalcemia and osteomalacia

Answer 22

phenytoin or phenobarbital

Question 23

Hypocalcemia can result from low magnesium levels which is related to

Answer 23

Alcoholism
cisplatin-based chemotherapy
Decreased PTH secretion and resistance to PTH Paradoxically

In rare instances, hypermagnesemia (divalent cation) can cause hypocalcemia

Question 24

Hyperphosphatemia that may cause hypocalceamia

Answer 24

Phosphate binds calcium

•Due to Rhabdomyolysis (e.g., crush injuries), renal failure, and tumor lysis syndrome, IATROGENIC

• Treatment involves reducing the serum phosphorus level
• Seizures can occur as the earliest manifestation

• **Intravenous calcium should not be given to hyper-phosphatemic patients because calcium-
phosphate salts can precipitate into soft tissues.g*

Question 25

Pancreatitis causing hypocalceamia

Answer 25

• The lipases autodigest omental and retroperitoneal fat into negatively charged ions that
tightly bind calcium in the ECF, resulting in hypocalcemia.

• Poor prognostic sign

Question 26

Chronic hyperphosphatemia can lead to

Answer 26

Soft tissue calcifications

Question 27

Pseudo-hyperphosphatemia

Answer 27

• Artifactually as a result of hemolysis

Question 28

Autosomal dominant hypophosphatemic rickets (ADHR)

Answer 28

Mutations in FGF23 that disrupt its breakdown