Which condition is characterized by increased bone resorption and can lead to complications like osteopenia?

The condition characterized by increased bone resorption, which can lead to complications like osteopenia, is hyperparathyroidism. This disorder is primarily due to an excess of parathyroid hormone (PTH), which regulates calcium levels in the blood. Elevated PTH levels increase the activity of osteoclasts, the cells responsible for bone resorption, leading to the breakdown of bone. This resorption process decreases bone density, resulting in osteopenia or potentially osteoporosis as bone mass continues to decline.

In hyperparathyroidism, the continuous signaling for bone resorption can also lead to other complications, such as bone pain and increased risk of fractures due to the weakened structure of bones. Elevated calcium levels in the blood can also occur as a consequence of this increased resorption, presenting additional health risks.

Other conditions listed, while they may affect bone health, do not specifically align with the mechanism of increased bone resorption leading to osteopenia. For instance, osteoarthritis primarily affects the cartilage and does not significantly lead to bone resorption. Paget's disease involves abnormal bone remodeling but typically involves both excessive resorption and formation, leading to disorganized bone growth rather than simply increased resorption. Osteosarcoma, a type of bone cancer