Osteoporosis - not just a women's disease
Primary vs. Secondary Gender Differences
Women most often develop primary osteoporosis, which is related to the drop in estrogen that occurs at menopause as a normal part of the ageing process. In contrast, approximately 50% of male osteoporosis cases have secondary causes. Secondary osteoporosis may be caused by other diseases, certain medications, and risk factors such as poor lifestyle choices. A few examples are:
- hypogonadism, often in men treated for prostate cancer with hormone therapy
- corticosteroid treatment for conditions like arthritis or asthma
- hyperthyroidism (overactive thyroid)
- alcoholism
- nutritional deficiencies, (eg: calcium, vitamin D)
Osteoporosis has traditionally been regarded as a disease of older women. In recent years there has been an increased awareness about osteoporosis in men. Despite growing research, the risk in males continues to be underestimated.
Estrogen and Testosterone
Osteoporosis in women is primarily related to a pronounced drop in estrogen at menopause. Although some men may have a decline in testosterone with age, it is not equivalent to menopause in women. In fact both testosterone and estrogen are important for maintaining healthy bones in men and women. Healthy testosterone levels are an important part of bone health; however estrogen is likely the primary hormone contributing to bone health in both genders. Estrogen concentrations in men are small but essential to bone health. For men with lower than normal testosterone levels (hypogonadism), testosterone replacement therapy may improve bone health.
Fracture Mortality Rate
Approximately one third of osteoporosis-related bone fractures occur in men. As in women, risk of bone fractures increase with age; however in men this increased risk occurs about 5 to 10 years later in life. Men have substantially higher death rates than women after fracturing a bone. One reason for this is men with osteoporosis often have other associated medical conditions and are less healthy overall. In fact, mortality rates after a fracture of the femur are two to three times higher in men. The mortality rates are similar for hip fractures; one study reports that men are twice as likely as women to die within a year after hip fracture. Vertebral fractures also have higher death rates in men.
Unfortunately, not enough men at risk of fracture are diagnosed with osteoporosis. Without a diagnosis, men miss out on treatments designed to prevent fractures. Screening is especially important so that fracture risk can be decreased with appropriate treatment.
Bone Mineral Density Values
A bone mineral density test is often used to diagnose osteoporosis. Much of what is known about bone health and osteoporosis results from studies done on women. Diagnosing osteoporosis in men can be more complicated. In men there is no agreed-upon bone mineral density level that indicates osteoporosis. The World Health Organization has defined osteoporosis based on the bone mineral density values of young adult women. However, fractures in men may occur at higher bone mineral density levels. There is ongoing debate about whether female values are valid in men or if male specific scores should be used.
