How does the bone profile appear in primary hyperparathyroidism?

How does the bone profile appear in primary hyperparathyroidism?

• A. Calcium low, PTH normal, phosphate low
• B. Calcium high, PTH high or inappropriately normal, phosphate low
• C. Calcium high, PTH low, phosphate high
• D. Calcium low, PTH high, phosphate normal

Answer: (B)

In primary hyperparathyroidism, the bone profile typically reveals elevated levels of calcium alongside high or inappropriately normal parathyroid hormone (PTH) levels, while phosphate levels are usually low. This condition is primarily caused by an overproduction of PTH, often due to a parathyroid adenoma. The excessive PTH leads to increased bone resorption, resulting in the release of calcium into the bloodstream, hence the elevated calcium levels. Meanwhile, the action of PTH on the kidneys enhances the excretion of phosphate, leading to lower phosphate levels. Although the PTH is elevated due to the pathology, it can sometimes be inappropriately normal due to the feedback mechanisms failing in conditions where calcium is persistently high. Understanding this biochemical and physiological interplay is essential in diagnosing primary hyperparathyroidism. The specific profile with high calcium, high or inappropriately normal PTH, and low phosphate is a classic finding that helps distinguish this condition from other disorders that may affect calcium and phosphate metabolism.

In primary hyperparathyroidism, the bone profile typically reveals elevated levels of calcium alongside high or inappropriately normal parathyroid hormone (PTH) levels, while phosphate levels are usually low.

This condition is primarily caused by an overproduction of PTH, often due to a parathyroid adenoma. The excessive PTH leads to increased bone resorption, resulting in the release of calcium into the bloodstream, hence the elevated calcium levels. Meanwhile, the action of PTH on the kidneys enhances the excretion of phosphate, leading to lower phosphate levels. Although the PTH is elevated due to the pathology, it can sometimes be inappropriately normal due to the feedback mechanisms failing in conditions where calcium is persistently high.

Understanding this biochemical and physiological interplay is essential in diagnosing primary hyperparathyroidism. The specific profile with high calcium, high or inappropriately normal PTH, and low phosphate is a classic finding that helps distinguish this condition from other disorders that may affect calcium and phosphate metabolism.