An overview of osteoporosis

Osteoporosis means a decrease in bone density and destruction of bone tissue, which leads to a disturbance in bone strength and an increase in the risk of fracture. More than 200 million people in the world suffer from osteoporosis. Osteoporosis affects both men and women, but the prevalence varies. One in three women and one in five men are at risk of fracture in their lifetime.

Osteoporosis can occur following a decrease in estrogen in the period after menopause (menopause), or it can be due to age-related changes or due to secondary causes such as disease or medication.

The most common sites of osteoporotic fractures are the wrist, spine, pelvis, and ribs. It is estimated that more than 80% of fragility fractures [1] after menopause are due to osteoporosis. A fragility fracture means a fracture caused by mild trauma (i.e. falling from a height less than standing).

Fractures are associated with pain, disability, disfigurement, and loss of independence, and osteoporosis imposes significant costs on the health care system. After a fragility fracture, the risk of another fracture is 2.5 times (for pelvic fractures) and more than 5 times (for vertebral fractures). Fractures are also associated with increased mortality, with a one-year mortality risk of 28% in women and 37% in men. Despite the societal impact of fractures, there is a care gap in the management of osteoporosis, and in fact less than 20% of patients with fragility fractures receive treatment.

1) Pathophysiology
Bone remodeling is a continuous process that is carefully regulated, resulting in a balance between bone resorption and bone formation in order to maintain optimal bone strength. Any imbalance in the normal bone remodeling process can lead to excessive bone resorption or decreased bone formation. If this process continues, it can lead to a decrease in bone mineral density and microarchitectural destruction [2], which leads to an increased risk of fracture. etc.), regulated by cytokines (eg RANKL) and other compounds (eg growth factor, vitamin D, prostaglandin etc.).

Osteoblasts produce receptor activator nuclear factor kappa B [3] RANKL, RANKL is a cytokine that plays a role in the differentiation, maturation and activation of osteoclasts. This cytokine binds to the RANK receptor on the osteoclast surface to initiate the differentiation, activation, and bone resorption process. Factors that affect this regulation (such as loss of estrogen during menopause, aging, certain conditions, or medications) can lead to an imbalance in normal bone physiology.