Osteocalcin

What is Bone Resorption?

It is the process that involves bone tissue breakdown by the action of osteoclasts resulting in the transfer of calcium from bone tissue to the blood. This condition is highly stimulated or inhibited following demand for calcium from various parts of the body. Low calcium levels in the blood stimulate the release of parathyroid hormone from the parathyroid glands. PTH increases the number and activity of existing osteoclasts. On continuous stimulation, greater levels of resorption of calcium and phosphorus from bones occur.

What happens to blood calcium levels in conditions of Bone Resportion?

Serum calcium levels will rise in conditions of bone resportion.

What is the role of Vitamin D in bone-related conditions?

Vitamin D increases absorption of calcium and phosphate in the intestinal tract, leading to elevated blood levels of calcium and thus it inhibits bone resorption. Calcitriol (vitamin D3) is the active form of vitamin D in the blood.

What is the role of calcitonin in bone-related disorders?

Calcitonin is a hormone secreted by the thyroid gland. it decreases osteoclast activity and the formation of new osteoclasts. Hence, it lowers bone resorption.

What are the other laboratory tests to diagnose conditions related to the bones?

The tests include estimation of serum calcium levels, serum ionic calcium levels, serum phosphorus, serum uric acid, serum vitamin D levels, serum protein electrophoresis for the M band ( to rule multiple myeloma).

What are the disorders occurring as a result of increased bone resorption?

Disorders related to bone resorption are osteoporosis, Paget’s disease of bone, osteolysis, osteopetrosis, etc. Elderly women have increased bone resorption rates post menopause following deficiency of estrogen.

What is Paget’s disease of bone?

This condition is also known as osteitis deformans. It is characterized by cellular remodeling and deformity of one or more bones. The affected bones on microscopic levels show dysregulated bone remodeling, excessive bone breakdown, and subsequent disorganized new bone formation.

What are the symptoms of Paget’s disease of bone?

The structural changes in bones cause to weaken the bone resulting in deformity, pain, fracture, or arthritis of associated joints.

What is Osteoporosis?

Osteoporosis is a systemic skeletal disorder characterized by low bone mass, micro-architectural deterioration of bone tissue leading to bone fragility, and increased risk of bone fracture.

Commonly affected bones are vertebrae in the spine, bones of the forearm, and the hip.

What is Ostemalacia?

Osteomalacia is a condition characterized by softening of bones. The major reason is defects in bone metabolism. Such impaired bone metabolism can be due to inadequate levels of phosphates, calcium, and vitamin D, or due to resorption of calcium. Impaired bone metabolism causes inadequate bone mineralization.

Osteomalacia in children is known as rickets.

What are the symptoms of Osteomalacia?

Symptoms include diffuse body pains, muscle weakness, and increased fragility of bones.

What is multiple Myeloma?

Multiple myeloma also known as plasma cell myeloma is a cancer of plasma cells. Plasma cells are a type of white blood cell that normally produce antibodies. This condition is characterized by bone pains, anemia, kidney dysfunction, and infections. Further complications will lead to amyloidosis, bone fractures, kidney-related disorders, hyperviscosity syndrome, and infections.

What is Osteonectin?

Osteonectin is a glycoprotein in the bone that binds to calcium. It is secreted by osteoblasts during bone formation, initiating mineralization of the bone. It also increases the production and activity of matrix metalloproteinases, which help in cancer invading into bone. Overexpression of osteonectin is seen in many human cancers such as brest, prostate, clon and pancreatic.

What are bone markers?

Bone markers include N-telopetide, tartarate resistant acid phosphatase (TRAP), bone-specific alkaline phosphatase, osteocalcin, procollagen type 1 N-terminal propeptide (P1NP)

What are bone density markers?

A DEXA scan is the most commonly used marker for measure bone density. It estimates the amount of bone minerals in bone tissue. It is used as an indirect indicator of osteoporosis and bone fracture. The procedure done is called densitometry and is often performed in the radiology or nuclear medicine department.

Does alcohol have any role in bone-related disorders?

Prolonged Ethanol exposure increased fracture risk by decreasing bone mineral density and promoting osteoporosis. Indirect effects of alcohol abuse occur by its effect on growth hormones, sex steroids, and oxidative stress.