From the Guidelines
The patient's lab results indicate hypoparathyroidism, and immediate treatment should include calcium supplementation and active vitamin D (calcitriol) to enhance calcium absorption, as recommended by the most recent guidelines 1. The lab results show low parathyroid hormone (PTH) at 9 pg/mL (normal range 15-65 pg/mL) and low calcium at 7.60 mg/dL (normal range 8.50-10.50 mg/dL). This pattern suggests hypoparathyroidism, where the parathyroid glands are not producing enough PTH.
Key Considerations
- Hypocalcemia associated with relative or absolute hypoparathyroidism is a common issue in patients with 22q11.2 deletion syndrome, and may arise or recur at any age 1.
- Regular investigations, including measurements of pH-corrected ionized calcium, magnesium, parathyroid hormone, and creatinine concentrations, are recommended 2.
- Daily calcium and vitamin D supplementation are recommended for all adults with 22q11.2DS, and magnesium supplementation for those with hypomagnesemia is indicated 2.
Treatment Recommendations
- Calcium supplementation, typically calcium carbonate 1000-1500 mg elemental calcium daily in divided doses, should be initiated to correct hypocalcemia.
- Active vitamin D (calcitriol) at 0.25-0.5 mcg daily should be started to enhance calcium absorption.
- Severe symptoms like tetany, seizures, or prolonged QT interval may require IV calcium gluconate.
- Regular monitoring of calcium levels is essential, aiming for low-normal range (8.5-9.0 mg/dL) to avoid complications.
- Dietary adjustments should include calcium-rich foods while limiting phosphorus-rich items.
- The underlying cause of hypoparathyroidism should be investigated, as it commonly results from neck surgery, autoimmune disorders, or genetic conditions.
- Treatment is typically lifelong, with dose adjustments based on regular calcium and PTH monitoring.
From the FDA Drug Label
A serum iPTH level of ≥ 100 pg/mL is strongly suggestive of secondary hyperparathyroidism. The patient's PTH, intact level is 9 pg/mL, which is below the threshold of ≥ 100 pg/mL that is strongly suggestive of secondary hyperparathyroidism.
- The patient's Ca level is 7.60 mg/dL, which is low. The patient's low PTH, intact level and low Ca level may suggest hypoparathyroidism rather than secondary hyperparathyroidism. 3
From the Research
Low PTH and Calcium Levels
- The patient's lab results show low PTH (9 pg/mL) and low calcium (7.60 mg/dL) levels, which are indicative of hypoparathyroidism 4.
- Hypoparathyroidism is a condition where the parathyroid glands do not produce enough parathyroid hormone (PTH), leading to low serum calcium levels and elevated serum phosphate levels 4.
Treatment Options
- Conventional treatment of hypoparathyroidism consists of oral calcium and active vitamin D supplements, with the goal of maintaining serum calcium levels within the lower end of normal 5.
- Alternate-day calcium dosing may be an effective treatment option for chronic hypoparathyroidism, as it has been shown to decrease oral calcium intake and increase serum calcium levels 6.
- Treatment with vitamin D2 may also be considered, as it has been shown to result in less severe hypocalcemia compared to calcitriol 7.
Health-Related Quality of Life
- Patients with hypoparathyroidism often experience low health-related quality of life (HRQoL), with lower physical and mental well-being scores compared to the general population 8.
- Low HRQoL is often associated with low calcium levels, and treatment with PTH analog may be considered in patients with both low HRQoL and low calcium levels 8.