What is osteoporosis?
What is osteoporosis?
Osteoporosis literally means “porous bones”, although is also defined as “a systemic, skeletal disease, characterized by low bone mass and micro-architectural deterioration of bone tissue, with a consequent increase in bone fragility and susceptibility to fracture”. Bones are made up of a thick outer shell and a strong inner mesh which looks like a honeycomb and consists of protein, calcium and other minerals.
The honeycomb structure is made up of struts of bone, and osteoporosis means that these struts become thin and break which in turn makes bones more porous and fragile. When bones become more fragile, they can break more easily even after a simple type of fall, for example, falling from standing height. This is known as a low trauma fracture and often it is this type of fracture that is the warning sign that someone may have osteoporosis.
How is bone formed?
Bone is highly specialized, living tissue, which is constantly changing and being renewed by a process known as bone remodeling, or bone turnover. This process basically involves cells called osteoclasts which break down and remove old bone and then cells called osteoblasts forming new bone and filling the cavity created by removing the old bone. This bone remodelling process continues throughout life but slows down as we get older. In childhood and adolescence the bone building cells (osteoblasts) work faster than the bone removing cells (osteoclasts) causing bones to increase in density and strength.
Bones continue to grow in strength until our midlate twenties when maximum strength known as peak bone mass is reached. Bone density is then maintained up until our mid-late thirties and then starts to decrease as part of the natural ageing process. In women there is increasing bone loss at the time of the menopause.
Osteoporosis in women.
Osteoporosis is estimated to affect 1 in 2 women over the age of 50. It is more common in women than in men mainly because of the affects of the menopause. The hormone estrogen is known to maintain bone density and help reduce the risk of fracture; therefore with decreasing estrogen levels at the time of the menopause bone loss is accelerated. Osteoporosis is also more common in women because they tend to have smaller, less dense bones than men and do not achieve as high a peak bone mass.
Osteoporosis in men.
Although osteoporosis is more common in women, it is still common in men with 1 in 5 being affected. In men it is often secondary to another health problem. Low levels of the male hormone testosterone (hypogonadism) can also cause osteoporosis, although in nearly half of all men who have osteoporosis the actual cause is unknown. This is known as idiopathic osteoporosis.
Comments on this entry are closed.