Osteoporosis shows no early symptoms as it begins creeping into the bodies of men and women during mid-life, but it can be prevented, according to a specialist in bone disease at the University of California San Francisco.
"We have all seen an older person at the shopping center who is bent over and cannot stand up straight because of a curve in the upper back. This is one of the most visible, everyday reminders of this bone-weakening disease associated with aging, but the good news is with our current medical understanding, we really do have the opportunity to turn it around or slow it down," says Nancy E. Lane, M.D., UCSF associate professor of medicine who treats patients at San Francisco General Hospital Medical Center.
People with osteoporosis have fragile bones that are very susceptible to fractures. An activity as mild as coughing can sometimes make the spinal vertebrae break, causing a person to become hunched over and in severe cases, to develop a noticeable hump in the back over several years and to lose several inches in height.
In a new book that she authored, The Osteoporosis Book: A Guide for Patients and Their Families, Lane outlines the life cycle of bone, how osteoporosis develops, who is at risk, and how the disease is diagnosed, treated, and prevented.
Organized as an educational guide, the book includes a summary of key points at the end of each chapter, profiles of typical patients to help readers identify themselves, steps to reduce risks, and sources for additional information, including newsletters and cookbooks.
"My goal was to present user-friendly information that will help the current generation of men and women, and the next generation, to all stand tall," Lane says.
Most people think of osteoporosis as a woman's disease because it does affect more women than men but, regardless of gender, it can severely influence quality of life, she emphasizes. About 25 million Americans suffer from osteoporosis: one of four women over age 65 and one of 10 men over age 80. The book includes a chapter specifically on osteoporosis in men.
Both women and men lose bone as they grow older; the difference is the amount of bone loss and the rate. Beginning at menopause, women lose bone rapidly as their estrogen level drops. In men, factors that influence onset are poor calcium absorption in the gastrointestinal tract related to aging and testosterone deficiency.
"Over the past decade we have begun to hear a lot more about osteoporosis as a silent disease and what can be done about it, which is a very positive step. The down side is that there is a lot of misinformation circulating. So it is important consumers researching this subject have accurate information," Lane says.
A common definition of osteoporosis is a disease in which a person loses bone, which can be a confusing explanation if a person doesn't know the biology of bone formation, she notes. "Bone-weakening is probably a better description."
"Bone weakening occurs because there is a significant change in the structure of bone and loss of bone mass. Through a complicated process called the bone remodeling cycle, bone constantly is being created and maintained throughout life. As we age, this process changes and we break down more bone than we make. Less bone mass results in weaker bone," she explains.
Many factors determine bone mass, with age, sex, race, and genetics as most important. With current medical technology, osteoporosis can be detected through a bone mass measurement, taken through scanning techniques such as ultrasound. Current drug treatments for the disease focus on reducing bone loss by slowing the change in bone mass.
The most common bone fractures of osteoporosis occur in the vertebrae, back, hip, forearm, or wrist. One of the most serious is a hip fracture, which usually results from a fall. While the fracture can heal normally, the accident often sets in motion a cascade of other health problems that are accelerated because of the person's age.
Women who fracture their hips tend to be less healthy than those who do not, according to Lane, and pneumonia is often a complication that proves fatal.
"Prevention of osteoporosis means prevention of low bone mass, and lifestyle factors are important. Our decisions on diet, medication, vitamin supplements, even the type of exercise we choose, will affect progression of the disease," Lane emphasizes. Here are some of the basics:
- Calcium, an important mineral for bone health, helps bone grow strong in
youth, maintains bone mass in middle age, and prevents some bone loss with
aging. Good sources are dairy products and calcium supplements.
- Vitamin D is essential for bone health. It promotes calcium intake and
maturation of bone cells. Good sources are sunlight and a daily multiple
vitamin.
- The best diet to maintain bone mass is moderately high in protein, with
plenty of fruits and vegetables.
- Men and women who perform weight-bearing exercise (walking, climbing stairs,
moderate weight-lifting) three to five times a week generally have more bone
mass than non-exercisers.
- Hormone replacement therapy (HRT) beginning at menopause and continuing 7-10
years gives women long-term protection against osteoporotic fractures. But like
any medication there are risks, including breast cancer, other cancers, clotting
problems, and gallstones, and each woman must evaluate her individual benefits
and risks, according to Lane.
- A combination of exercise and estrogen therapy is necessary to build bone in early menopause.
The Osteoporosis Book is published by Oxford University Press. For more information or to participate in a question-answer dialogue with the author, log on to the website at www.osteoporosisguide.com.
NOTE TO THE MEDIA: May is National Osteoporosis Prevention Month. For review copies of The Osteoporosis Book or to arrange an interview with Nancy Lane, M.D., contact Corinna Kaarlela in the UCSF/SFGHMC News Office at 415-476-3804. Dr. Lane also can be reached directly for interviews at 415-206-6654.