Secondary Hyperparathyroidism

Question 1

Define secondary hyperparathyroidism.

Answer 1

Any disorder that results in hypocalcaemia will elevate parathyroid hormone levels and can serve as a cause of secondary hyperparathyroidism. The most frequent causes of the condition are chronic kidney disease (CKD), malabsorption syndromes, and chronic inadequate sunlight exposure, acting via alterations in vitamin D, phosphorus, and calcium.

Question 2

Explain the aetiology/risk factors of secondary hyperparathyroidism.

Answer 2

Ageing
Chronic renal failure
Vitamin D deficiency: inadequate sunlight exposure
Nutritional deficiency (especially absence of dairy products and fish)
Vitamin D deficiency: malabsorption

Question 3

Summarise the epidemiology of secondary hyperparathyroidism.

Answer 3

Twenty-six million American adults have CKD and millions of others are at increased risk of vitamin D deficiency. Over 60% of these patients are at risk for the development of secondary hyperparathyroidism. Virtually all dialysis-dependent chronic renal failure patients develop secondary hyperparathyroidism.

Question 4

Recognise the presenting symptoms of secondary hyperparathyroidism. Recognise the signs of secondary hyperparathyroidism on physical examination.

Answer 4

Features of chronic renal failure
Features of underlying malabsorption syndrome
Muscle cramps and bone pain
Perioral tingling or paresthesia in fingers or toes
Chvostek’s sign
Trousseau’s sign
Bowed legs or knock knees
Fractures

Question 5

Identify appropriate investigations for secondary hyperparathyroidism and interpret the results.

Answer 5

Serum calcium
Serum intact parathyroid hormone (iPTH)
Serum creatinine
Serum urea nitrogen

Question 6

Generate a management plan for secondary hyperparathyroidism.

Answer 6

Treat the cause. Apart from CKD, most causes can be treated with better nutrition and vitamin D supplementation.

Question 7

Identify the possible complications of secondary hyperparathyroidism and its management.

Answer 7

Osteodystrophy
Osteoporosis
Uraemia
Calciphylaxis

Question 8

Summarise the prognosis for patients with secondary hyperparathyroidism.

Answer 8

The patient outlook for secondary hyperparathyroidism mirrors the underlying disease. In patients with chronic kidney disease, aggressive electrolyte management will help optimise the situation; many patients will require calcimimetics, a treatment that has reduced the frequency of surgery for this condition.