What does a PTH (Parathyroid Hormone) level of 215 indicate and how is it managed?

Elevated PTH Level of 215: Diagnosis and Management

A PTH level of 215 pg/mL is significantly elevated and most likely indicates hyperparathyroidism, which requires further evaluation to determine whether it is primary, secondary, or tertiary hyperparathyroidism based on calcium levels and other laboratory parameters.

Diagnostic Approach

Initial Assessment

• Measure serum calcium levels immediately:
  • If calcium is elevated (>10.5 mg/dL): Suggests primary hyperparathyroidism (PHPT)
  • If calcium is normal: Consider normocalcemic primary hyperparathyroidism or secondary causes
  • If calcium is low: Suggests secondary hyperparathyroidism (SHPT)

Additional Laboratory Tests

• Complete CKD-MBD panel 1:
  • Serum phosphorus (low in PHPT, high in SHPT)
  • 25-hydroxyvitamin D level (to rule out vitamin D deficiency)
  • Alkaline phosphatase (marker of bone turnover)
  • Kidney function tests (BUN, creatinine, eGFR)

Potential Causes to Consider

1. Primary Hyperparathyroidism:

   • Characterized by autonomous PTH secretion from parathyroid gland(s)
   • Usually presents with hypercalcemia and elevated or inappropriately normal PTH 2
   • May be due to adenoma, hyperplasia, or rarely carcinoma

2. Secondary Hyperparathyroidism:

   • Most commonly due to:
     • Chronic kidney disease (CKD)
     • Vitamin D deficiency
     • Malabsorption syndromes
     • Medications (e.g., certain diuretics)
   • Presents with elevated PTH and normal or low calcium 3

3. Tertiary Hyperparathyroidism:

   • Occurs after longstanding secondary hyperparathyroidism
   • Often seen after kidney transplantation
   • Characterized by autonomous PTH secretion despite correction of the underlying cause 4

Management Approach

For Primary Hyperparathyroidism

• Surgical parathyroidectomy is the definitive treatment if:
  • Serum calcium >1 mg/dL above upper limit of normal
  • Evidence of target organ damage (kidney stones, osteoporosis)
  • Age <50 years
  • If surgery is contraindicated, consider medical management

For Secondary Hyperparathyroidism

• Treatment depends on the underlying cause:

If due to CKD:

• Target PTH levels vary by CKD stage 1:

  • CKD G3: <70 pg/mL
  • CKD G4: <110 pg/mL
  • CKD G5: <300 pg/mL
  • CKD G5D (dialysis): 150-600 pg/mL

• Treatment algorithm based on PTH level 1:

  1. PTH 215 pg/mL with mild elevation:

     • Optimize calcium intake
     • Correct vitamin D deficiency
     • Limit dietary phosphorus to 800-1000 mg/day

  2. If PTH persists 300-500 pg/mL:

     • Increase vitamin D sterols
     • Adjust phosphate binders

  3. If PTH rises to 500-800 pg/mL:

     • Higher doses of vitamin D sterols
     • Consider adding cinacalcet (starting at 30 mg once daily, titrating every 3-4 weeks to maximum 180 mg daily) 5

  4. If PTH >800 pg/mL:

     • Consider parathyroidectomy if medical therapy fails

If due to Vitamin D deficiency:

• Vitamin D supplementation
• Calcium supplementation if needed
• Recheck PTH, calcium, and vitamin D levels after 2-3 months of therapy

For Tertiary Hyperparathyroidism

• Parathyroidectomy (total, subtotal, or limited) is the primary treatment 4
• Medical management with calcimimetics (cinacalcet) may be considered in poor surgical candidates

Monitoring

• Follow calcium, phosphorus, and PTH levels regularly:
  • Every 3-6 months initially
  • Every 6-12 months once stable
• Monitor for complications:
  • Bone disease (osteoporosis, fractures)
  • Kidney stones or nephrocalcinosis
  • Cardiovascular calcifications
  • Neuromuscular symptoms

Important Considerations

• PTH measurement can be affected by various factors 3:

  • Race (higher in Black individuals)
  • Age (increases with age)
  • BMI (higher in obesity)
  • Vitamin D status
  • Assay type and standardization
  • Time of collection (circadian rhythm)

• Elevated PTH is associated with:

  • Bone loss
  • Soft tissue calcification
  • Cardiomyopathy
  • Immunodeficiency
  • Impaired erythropoiesis
  • Increased energy expenditure
  • Muscle weakness 6

By systematically evaluating calcium levels and other parameters, the specific type of hyperparathyroidism can be determined, leading to appropriate management strategies to reduce morbidity and mortality associated with chronically elevated PTH.