Osteoporosis
Osteoporosis happens when bones lose minerals, such as calcium, more quickly than the body can replace them (increased bone turnover) leading to a loss of bone thickness (bone mass or density). As a result, bones become thinner and less solid, so that even a minor bump or accident can cause serious fractures, especially in the spine, wrist, and hip. Though often without symptoms osteoporosis can have a major effect on quality of life, causing a man pain, disability, depression, loss of independence and social isolation. When bone fractures happen, there may be a loss of height or curvature of the spine that can impair lung functioning and normal breathing, and life expectancy may be reduced.
How common is osteoporosis in men?
Though less common than in women, osteoporosis is a major, seriously under-recognized and undertreated problem in men. According to Osteoporosis Canada at least one in eight Canadian men over age 50 have osteoporosis (compared to one in four Canadian women). Even though osteoporotic fractures are about one half as common in men as in women, these fractures are associated with higher disability and death than in women (nearly 40% greater than that of women). It is projected that there will be 88,000 hip fractures and 7,000 deaths by the year 2041, highlighting the serious implications unless fracture rates are reduced by some form of intervention.
Why does osteoporosis happen with aging?
During childhood the skeleton is growing and the bones are changing shape (modeling) as well as remodeling. Just after age 20, the bone mineral density reaches its maximum strength, known as the peak bone mass. The major determinant of peak bone mass is probably the family history (genetics), but it can also be influenced by diseases in early life, such as intestinal diseases that affect calcium and/or vitamin D absorption (for example celiac disease), and by medications such as glucocorticoids (given, for example, to treat asthma or childhood arthritis or inflammatory bowel disease). An insufficient dietary intake of calcium and/or vitamin D during childhood would also be expected to limit the achievement of peak bone mass, as would delayed puberty.
Bone mineral density declines with age, particularly after the age of 40. When bone mass begins to fall, it is more gradual in men than women, but accelerates after the age of about 70 years. In men and women, the female hormone estrogen controls bone turnover and in men may be important for peak bone mass (estrogen is present in much lower amounts in men than in women, but is important to a man's skeletal health).
Women generally have less bone mass than men and women's bones lose calcium and other minerals at a much faster rate after menopause due to a decrease in their estrogen levels. Lack of estrogen in men is also likely to reduce bone formation, which leads to a decrease in bone mass. In some men, low testosterone levels may cause bone thinning, a decrease of muscle mass and increase the rate of bone turnover so bones become less solid. Men with proven (clinically confirmed) low testosterone levels (testosterone deficiency) are therefore more likely to have bone fractures compared to men with normal testosterone levels. Studies of elderly male residents of nursing homes have found that up to 66% of those with hip fractures and 20% of those with vertebral fractures have low testosterone levels.
In men and women over the age of 65, the intestine cannot absorb calcium from food as well as in youth. A hormone known as the parathyroid hormone from the parathyroid glands in the neck is produced at a higher rate and makes the bones give up their calcium into the blood stream. This hormone increases in production with age and makes the bones lose more calcium to become thinner. Taking calcium tablets to increase the amount absorbed from the intestine may help older people reduce bone loss.
