Is secondary hyperparathyroidism a feature of PPHP?

Is secondary hyperparathyroidism a feature of PPHP?

• A. No
• B. Yes
• C. Only after renal transplant
• D. Not documented

Answer: (A)

Secondary hyperparathyroidism arises when PTH is inappropriately elevated in response to hypocalcemia or phosphate retention. In pseudopseudohypoparathyroidism (PPHP), calcium and phosphate levels are normal and there is no PTH resistance, so the parathyroid axis remains appropriately regulated. That means PTH levels are not chronically elevated, and secondary hyperparathyroidism does not occur. So PPHP does not feature secondary hyperparathyroidism.

Secondary hyperparathyroidism arises when PTH is inappropriately elevated in response to hypocalcemia or phosphate retention. In pseudopseudohypoparathyroidism (PPHP), calcium and phosphate levels are normal and there is no PTH resistance, so the parathyroid axis remains appropriately regulated. That means PTH levels are not chronically elevated, and secondary hyperparathyroidism does not occur. So PPHP does not feature secondary hyperparathyroidism.