Hyperphosphatemia

Answer is B (Hyperparathyroidism):

Hyperparathyroidism is typically associated with hypophosphatemia.

Primary Hyperparathyroidism is associated with Hypophosphatemia and Hypercalcemia while Secondary Hyperparathyroidism is associated with Hypophosphatemia and Hypocalcemia.

Hyperthyroidism is typical associated with normal phosphate levels

Hypoparathyroidism and Pseudohypoparathyroidism are associated with Hyperphosphatemia

Answer is A (Pseudohypoparathyroidism):

The presence of hyperphosphatemia (Serum phosphate) along with characteristic brachydactyly suggests the diagnosis of pseudohypoparathyroidism.

Pseudohypoparathyroidism

• This is a hereditary disorder associated with symptoms and signs of hypoparathyroidism despite an elevated PTH level (pseudohypoparathyroidism)
• This is produced as a result of deficient end organ response to PTH.

Answer is A and B (CRF and Pseudohypoparathyroidism):

CRF and Pseadohypoparathyroidism are associated with Hypocalcemia and Hyperphosphatemia

Hypocalcemia with Hyperphosphatemia:

• Chronic Renal Failure
• True Hypoparathyroidism
• Pseudo hypoparathyroidism
• Tumor lysis syndrome
• Rhabdomyolysis

Answer is A (Acute renal failure):

Renal insufficiency is associated with hyperphosphatemia due to impaired renal phosphate excretion.

Acute renal failure: ‘Mild Hyperphosphatemia is an almost invariable complication of Acute Renal Failure.

Severe hyperphosphatemia may develop in highly catabolic patients or following rhabdomyolysis, hemolysin or tumor lysis.’ — Harrison 16^th / 1650

Diabetic ketoacidosis or Metabolic acidosis from any other causes may be associated with hyperphosphatemia from transcellular phosphatic shifts.

However resolving phases of diabetic ketoacidosis are associated with hypophosphatemia and not hyperphosphatemia. This is a result of insulin therapy for diabetic ketoacidosis.

Causes of hyperphosphatemia                                                Causes of hypophosphatemia

Metabolic acidosis                                                                  Insulin therapy of diabetic ketoacidosis or prolonged

(Lactic acidosis / Diabetic Ketoacidosis)                                    hyperglycemia.

Laboratory values in DKA / Harrison 6^th / 323 – 324

Phosphate values are : decreased

(large changes occurs during treatment of DKA

Also note that total body stores of phosphorus (Also potassium, sodium, chloride, magnesium) are reduced in DKA, but are not accurately reflected by their levels (serum values may be increased) because of dehydration and hyperglycemia. — Harrison

• Respiratory alkalosis is associated with hypophosphatemia by causing intracellular shift of phosphorus into cells.
• Hypophosphatemia        • Hyperphosphatemia
• Metalbolic alkalosis        • Metabolic acidosis
• Respiratory alkalosis      • Respiratory acidosis
• Chronic alcoholism / Alcoholism is known to cause hypophosphatemia. — Harrison 16^th / 881 

Severe hypophosphatemia is common and multifactorial in alcoholic patients.

Chronic alcohol use results in a decrease in the renal threshold of phosphate excretion.’ — CMDT

• Patients with COPD and Asthma  commonly have hypophosphatemia.

This is attributed to xanthine derivatives causing shifts of phosphate intracellularly and the phosphaturic effects of beta — adrenergic agonists, loop diuretics, xanthine derivatives and corticosteroids. — CMDT 2006 / 88