THE PHYSICIAN AND SPORTSMEDICINE - VOL 31 - NO. 10 - OCTOBER 2003
Osteoporosis in Men
Who's at Risk?
Public health efforts have successfully reduced the burden of osteoporosis on women, and now experts—who anticipate an epidemic of the disease in men in the coming decades—say it's time to do the same for men.
How Great a Risk?
Many men, and perhaps even some of their healthcare providers, might be surprised to know that a man's risk of an osteoporosis-related fracture is greater than his risk of prostate cancer. The National Institutes of Health (NIH) estimates that 2 million US men have osteoporosis1; an additional 8 million to 13 million are thought to have low bone mass.
The number of men who have osteoporosis is expected to rise dramatically as more men live longer. According to the NIH, the number of men older than 70 will double between 1993 and 2050. As men age, they don't undergo an intensive phase of bone loss as do menopausal women. But by age 65 to 70, men and women lose bone at similar rates. Thirty percent of hip fractures occur among men,2 and one study showed that because men develop osteoporosis at an older age, hip fracture mortality in men is greater than in women.3
Screening and Diagnosis
Typically, osteoporosis isn't diagnosed in a man unless he experiences a fracture. Though no medical groups have issued formal screening recommendations for men, Clifford J. Rosen, MD, director of the Maine Center for Osteoporosis Research and Education in Bangor, Maine, says that it's prudent to use routine physical exams to screen male patients who are 65 or older or any man who has had a fracture or unexplained back pain or height loss, or has osteoporosis risk factors.
A recent article in American Family Physician4 recommends that physicians monitor certain patients for asymptomatic vertebral fractures: those who have had more than 1-1/2 in. of height loss and those whose distal ribs touch the pelvic rim.
Rosen recommends including questions about family history of osteoporosis during the medical history. If a man's mother or father had the disease, that individual is significantly more likely to have osteoporosis than a man without such family history, he says.
Primary causes of osteoporosis in men are related to aging or genetic factors. Screening can identify secondary risk factors (table 1), such as use of glucocorticoid medication, anticonvulsant therapy, hypogonadism, alcohol abuse, smoking, gastrointestinal disorders that impair absorption, hypercalciuria, chronic disease (eg, chronic obstructive pulmonary disease, asthma, rheumatoid arthritis, or cancer), poor nutritional status, and immobilization.
Routine bone density studies are not recommended for men. Medicare limits bone density studies to men who have radiographic evidence of vertebral fracture, primary hyperparathyroidism, glucocorticoid excess, and osteoporosis treatment follow-up. Marc Hochberg, MD, MPH, an osteoporosis researcher and professor of medicine at the University of Maryland School of Medicine in Baltimore, says clinicians should use gender-specific data to calculate T scores for male patients who require bone density screening. The National Health and Nutrition Examination Survey (NHANES) and device manufacturers have developed data that allow men's T scores to be calculated, he says, noting that the definition of osteoporosis in men is a T score of -2.5 or below.
Once a man is diagnosed with osteoporosis, it's important to identify and treat any contributing factors, such as low hormone levels. Hochberg says serum total and free testosterone levels should be measured to determine whether hormone supplementation is appropriate. "Research studies suggest that estradiol levels are actually more important than serum testosterone levels; however, in clinical practice, we don't measure serum estradiol levels in men," he says.
Though most osteoporosis medications have been developed for and studied only in women, a few have been approved by the Food and Drug Administration for the treatment of osteoporosis in men. Alendronate sodium was approved in 2001 for the treatment of osteoporosis in men. Risedronate sodium has been approved for the treatment of glucocortocoid-induced osteoporosis in both men and women. Teriparatide (parathyroid hormone) was approved in November 2002 for increasing bone mass in men who are at risk for fracture or are hypogonadal. "That's a big one," Rosen says of teriparatide's approval.
Raising the Topic With Patients
Rosen says osteoporosis prevention can be a tough sell in patients, who may not be convinced of the risks in men. "I like to talk to men about osteoporosis when they come in with their wives," he says. "Their wives know all about osteoporosis, so they can nag their husbands about prevention at home."
Exercise is crucial, Hochberg says, especially for men who have low bone density. "Weight-bearing exercise to maintain or increase muscle strength and balance will provide synergism with the medication to increase bone mineral density and also help prevent falls," he says.
Hochberg says talking to patients about lifestyle changes is important, particularly smoking cessation and limiting alcohol intake to no more than two drinks per day.
Physicians should review patients' calcium intake, Rosen says. "Men do better than women with calcium intake, but it's still poor. Men need to get 1,000 mg of calcium a day, plus adequate vitamin D. They can get both in a multivitamin," he says.
Researchers are hoping to answer several questions about men's bone health. "One of the biggest questions is how common [osteoporosis] is. We still have a ways to go to determine the extent of the disease," Rosen says.
Rosen and his group are studying genetic markers for osteoporosis in men. "There are a couple potential genes associated with bone mass, but this isn't ready for prime time yet," he notes.
Hochberg's group is tracking changes in bone density over time in older black and white men. (Osteoporosis is twice as common in white men as in black men.) He says his group recently applied for NIH funding to study prognosis after hip fracture in men.
Other osteoporosis researchers are studying the use of peripheral devices to measure bone mineral density in men, and examining other treatments for fracture prevention.
When Are AEDs Cost-Effective?
Sports medicine physicians are often asked for their input on the purchase and deployment of automated external defibrillators (AEDs). Cost considerations often enter the discussion, and until now there has been little in the medical literature to help evaluate whether or not the devices are good financial investments.
Researchers at the University of Iowa and University of Michigan recently analyzed the value of installing defibrillators in various public locations. They determined that an AED is a good investment if its location was expected to be the site of at least one cardiac arrest every 7 years. Their findings, published in the September issue of the Journal of General Internal Medicine, are based on a review of existing studies and data on defibrillator placements in the Seattle area.
Peter Cram, MD, assistant professor of internal medicine at the University of Iowa and lead author of the study, said in a press release that the study supports the American Heart Association recommendation that defibrillators be placed in public locations where there is a one in five chance that the defibrillator will be used in a given year. "However, defibrillators also are being placed in a number of low-risk public locations where the money might be better spent in other ways, such as improving the existing emergency medical service program," he said. Purchasing AEDs for sports-related sites—sports venues, golf courses, and health clubs—appears to be a good investment, the study found. Sites such as hotels, large retail stores, and primary care centers were found to have lower risks.
Though not evaluated in the study, churches and public schools are thought to be low-risk sites, Cram said, because they play host to low-to-moderate risk populations for limited hours each week. Cram said that he understands the impulse for such groups to buy devices, but he wonders if other interventions such as preventive health screenings would more effectively improve those populations' well-being.
In a follow-up study, the researchers will survey public schools to assess defibrillator use and the number of cardiac arrests at the sites. Cram says public schools have been targeted aggressively for AED placement.
The study found that the cost-effectiveness of AED placement is reduced by the failure to use it on a nearby cardiac arrest victim. Therefore, the researchers emphasize that it's critical that AEDs be accessible and easily identifiable to potential responders.
Teams Sports Reduce Health Risks
High school students who are both physically active outside school and participate in team sports appear to be at a lower risk for smoking, drug use, and risky sexual behaviors, according to a Centers for Disease Control and Prevention study. Researchers reported their findings in the September issue of The Archives of Pediatric and Adolescent Medicine.
Researchers used data from the 1999 National Youth Risk Behavior Survey that was completed by 15,349 US high school students. The authors found that about 42% of the students were both physically active and participated in team sports, 22% were only physically active, 13% only played sports, and 22% were inactive and did not play sports. Inactivity levels were about 14% greater in girls than in boys, and team sports participation among boys was about 14% greater than in girls.
Previous studies have shown a negative relationship between being physically active and using cigarettes and marijuana, and other studies have shown that students who participated in sports were less likely to abuse substances or engage in risky behaviors. This study evaluated the effects of both types of activity.
Which Exercise Intensity for Dieters?
The ideal exercise intensity for dieting patients has been the topic of much debate over the past years; however, researchers from the University of Pittsburgh recently found strong evidence that moderate exercise is as effective as vigorous exercise.
The study, published in the September 9 issue of The Journal of the American Medical Association, involved 201 women who undertook a 12-month university-based weight control program. Participants were randomly assigned to one of four exercise groups that varied by intensity and duration. Participants lost between 8% to 10% of their body weight following the exercise and diet interventions.
Though there were no significant weight loss differences between the groups regarding exercise intensity, researchers did find that those who did a greater amount of exercise lost more weight. They concluded that initial interventions should target adoption of moderate-intensity exercise and that, when appropriate, patients should eventually progress to the Institute of Medicine's exercise recommendation of 60 minutes per day.