From the Guidelines
The patient's laboratory values are consistent with primary hyperparathyroidism, and management should focus on monitoring or surgical intervention, depending on symptomatology and degree of hypercalcemia, with consideration of medical management to control calcium levels and prevent complications. The elevated serum calcium (10.8 mg/dL) combined with a non-suppressed PTH level (77 pg/mL) is characteristic of primary hyperparathyroidism 1. The phosphorus is low-normal (2.5 mg/dL), which is consistent with PTH's phosphaturic effect. The 24-hour urine calcium is elevated at 260 mg, indicating increased calcium excretion. The normal creatinine (0.8 mg/dL) suggests preserved kidney function, and the 25-OH vitamin D level is adequate at 30 ng/mL, which is above the threshold for vitamin D insufficiency as defined by the KDOQI clinical practice guideline for nutrition in children with CKD 1.
Key considerations in management include:
- Monitoring for asymptomatic patients with mild hypercalcemia
- Parathyroidectomy for symptomatic patients or those with significant hypercalcemia
- Medical management to include increasing fluid intake, avoiding thiazide diuretics, limiting calcium intake to RDA levels, and ensuring adequate vitamin D levels
- Consideration of cinacalcet for patients who are not surgical candidates, as it may help decrease serum levels of PTH and FGF23, although it is not licensed for this indication and has been associated with severe adverse effects 2
- Further evaluation should include bone density testing and renal imaging to assess for complications, with careful consideration of the potential risks of nephrocalcinosis associated with high phosphate doses and hypercalciuria 2.
Given the potential for secondary hyperparathyroidism to aggravate phosphaturia and promote bone resorption, therapies should be adjusted to keep PTH levels within the normal range (10–65 pg/ml in children and adults) 2. However, the primary concern in this patient is the management of primary hyperparathyroidism, and treatment should be tailored to address this condition while minimizing the risk of complications.
From the Research
Laboratory Results Interpretation
The provided laboratory results are:
- Calcium: 10.8 mg/dL
- Creatinine: 0.8 mg/dL
- Phosphorous: 2.5 mg/dL
- PTH: 77 pg/mL
- 25-OH vitamin D: 30 ng/mL
- 24-hour urine calcium: 260 mg
Secondary Hyperparathyroidism
The patient's PTH level is 77 pg/mL, which is elevated. According to 3, high-dose ergocalciferol can decrease PTH levels in patients with stage III-IV CKD. However, the patient's 25-OH vitamin D level is 30 ng/mL, which is considered insufficient 4.
Vitamin D Insufficiency
The patient's 25-OH vitamin D level is 30 ng/mL, which is below the recommended level. According to 5, nutritional vitamin D is suggested as first-line therapy to treat secondary hyperparathyroidism with low 25(OH)D insufficiency.
Treatment Options
The patient's laboratory results suggest secondary hyperparathyroidism due to vitamin D insufficiency. Treatment options include:
- Vitamin D supplementation to increase 25-OH vitamin D levels 3, 4
- Monitoring of PTH levels to assess response to treatment 3, 4
- Consideration of other treatment options, such as calcimimetics or parathyroidectomy, if medical therapy is ineffective 6
Calcium and Phosphorus Levels
The patient's calcium level is 10.8 mg/dL, which is slightly elevated. The phosphorus level is 2.5 mg/dL, which is within normal limits. According to 7, secondary hyperparathyroidism can lead to abnormalities in calcium and phosphorus metabolism.
Urine Calcium Excretion
The patient's 24-hour urine calcium excretion is 260 mg, which is within normal limits. According to 3, high-dose ergocalciferol did not significantly change serum calcium or urine calcium excretion in patients with stage III-IV CKD.