From then on, bone loss occurs gradually and progressively in both men and women for the remainder of our lives. In women, there is an acceleraton of bone loss in the first few years after menopause. Peak bone mass is mainly determined by heredity. Individuals with a family history of osteoporosis frequently have lower than average bone mass, even as young adults. Peak bone mass may also be influenced by calcium intake and the amount of exercise during the growth years.
Many factors can influence the rate of bone loss.
These include the age at which menopause occurs, calcium intake, level of physical activity, lifestyle factors such as the use of alcohol and tobacco, and a variety of medical problems which can interfere with bone health, including low male hormone levels in men. All of these risk factors for osteoporosis increase the normal rate of bone loss. When we measure bone density, we determine the combined effects of peak bone mass and the subsequent loss of bone. According to the National Institute of Health, more than 28 million Americans are affected by osteoporosis today, and the disease leads to a million and a half fractures each year in this country. One out of every two women and one in eight men over 50 will have an osteoporosis-related fracture in their lifetime.