Which statement best describes a bone-related finding in primary hyperparathyroidism?

Which statement best describes a bone-related finding in primary hyperparathyroidism?

• A. ↓ cortical bone mineral density
• B. Hyperparathyroidism does not affect bones
• C. Osteosclerosis
• D. Normal bone density

Answer: (A)

Excess parathyroid hormone drives bone remodeling toward resorption, with a preferential impact on cortical bone. This results in a decrease in cortical bone mineral density, making bones thinner and more prone to fracture. In primary hyperparathyroidism, the high PTH level stimulates osteoclast activity indirectly through osteoblasts (increasing RANKL and reducing OPG), leading to high bone turnover and net loss of cortical bone, which is why decreased cortical BMD is the best-described bone finding. The other options don’t fit because PHPT does affect bones and typically does not cause osteosclerosis or normal bone density; instead, bone density tends to be reduced, particularly in the cortical compartment.

Excess parathyroid hormone drives bone remodeling toward resorption, with a preferential impact on cortical bone. This results in a decrease in cortical bone mineral density, making bones thinner and more prone to fracture. In primary hyperparathyroidism, the high PTH level stimulates osteoclast activity indirectly through osteoblasts (increasing RANKL and reducing OPG), leading to high bone turnover and net loss of cortical bone, which is why decreased cortical BMD is the best-described bone finding. The other options don’t fit because PHPT does affect bones and typically does not cause osteosclerosis or normal bone density; instead, bone density tends to be reduced, particularly in the cortical compartment.