What does high PTH mean and how is it managed?

Management of Elevated Parathyroid Hormone (PTH)

Elevated PTH levels require specific treatment approaches based on the underlying cause, with management strategies ranging from medical therapy to surgical intervention depending on disease severity and calcium levels.

Types of Hyperparathyroidism

• Primary hyperparathyroidism is characterized by autonomous parathyroid function, typically with hypercalcemia, though normocalcemic variants exist 1
• Secondary hyperparathyroidism occurs when PTH increases in response to a stimulus (commonly low serum calcium, vitamin D deficiency, or chronic kidney disease), with normal calcium and elevated PTH 2, 3
• Tertiary hyperparathyroidism develops after longstanding secondary hyperparathyroidism, when parathyroid glands become autonomous despite correction of the underlying cause, often resulting in hypercalcemia 4, 2

Diagnostic Evaluation

• Measure serum calcium, phosphate, 25-OH vitamin D, and intact PTH levels to determine the type of hyperparathyroidism 5
• Ensure 25-OH vitamin D levels are >20 ng/ml (50 mmol/l) to exclude vitamin D deficiency as a cause of secondary hyperparathyroidism 6, 5
• Evaluate dietary calcium intake through dietary assessment, as calcium deficiency can contribute to secondary hyperparathyroidism 6, 5

Management of Secondary Hyperparathyroidism

In Chronic Kidney Disease:

• First-line interventions include controlling serum phosphorus through dietary phosphorus restriction and phosphate binders 3
• Ensure adequate vitamin D status by supplementing with native vitamin D (cholecalciferol or ergocalciferol) to achieve 25-OH vitamin D levels >20 ng/ml 6, 3
• For patients with elevated PTH while on therapy with oral phosphate and active vitamin D, increase the dose of active vitamin D and/or decrease the dose of oral phosphate supplements 6
• In cases of persistent hypercalciuria and/or hypercalcemia, reduce or stop active vitamin D and phosphate supplements 6

Medical Therapy Options:

• Active vitamin D analogs (calcitriol, paricalcitol, doxercalciferol) effectively suppress PTH with varying effects on calcium and phosphorus levels 7
• Calcimimetics (cinacalcet, etelcalcetide) may be considered for severe hyperparathyroidism despite normocalcemia or in hypercalcemic hyperparathyroidism unresponsive to other treatments 6, 8
• Cinacalcet should be used with caution due to potential adverse effects including hypocalcemia and increased QT interval 6, 8

Surgical Management

• Parathyroidectomy is indicated for severe hyperparathyroidism with hypercalcemia that precludes medical therapy 6, 9
• Surgical options include total parathyroidectomy (TPTX), total parathyroidectomy with autotransplantation (TPTX+AT), and subtotal parathyroidectomy (SPTX) 6, 3
• Preoperative imaging with 99 Tc-Sestamibi scan, ultrasound, CT scan, or MRI should be performed prior to parathyroid surgery 6, 9
• For persistent hypercalcemic hyperparathyroidism, parathyroid resection should be considered 6

Post-Treatment Monitoring

• For patients on medical therapy, monitor serum calcium and phosphorus monthly and measure intact PTH every 1-3 months until target levels are achieved 3
• After parathyroidectomy, monitor ionized calcium every 4-6 hours for the first 48-72 hours to detect hypocalcemia 9, 3
• Provide calcium supplementation if hypocalcemia develops post-surgery 9, 3

Special Considerations

• In X-linked hypophosphatemia with normocalcemic hyperparathyroidism, active vitamin D might be given without phosphate supplements if careful follow-up is guaranteed 6, 5
• For patients with tertiary hyperparathyroidism after kidney transplantation, parathyroidectomy is often necessary when hypercalcemia persists 4, 2
• Avoid total parathyroidectomy in patients who may subsequently receive a kidney transplant, as control of serum calcium levels may be problematic 6