Although osteoporosis is commonly thought of as a disease that affects women, osteoporotic fractures also result in considerable morbidity and mortality in men. However, the disease is substantially underdiagnosed and undertreated in this population. Rates of osteoporosis in men are estimated to increase nearly 50 percent in the next 15 years, and rates of hip fracture are projected to double or triple by 2040.

Risk Factors

One meta-analysis found that the most notable risk factors for osteoporosis in men include age older than 70 years, low body weight (body mass index less than 20 to 25 kg per m²), weight loss of more than 10 percent, physical inactivity, use of oral corticosteroids, and previous fragility fracture (Table 1). However, most of the studies in this review included men older than 50 years from the United States and Europe, so the findings cannot be generalized to other populations.

Androgen deprivation (orchiectomy or pharmacologic therapy) is a strong predictor of osteoporosis and fractures associated with low bone mineral density (BMD). Alcohol use increases the probability of fracture, but has not been associated with decreased BMD. Cigarette smoking and low intake of dietary calcium are moderate predictors of an increased risk for low bone mass. They are likely risk factors for fracture, as well, but the evidence for this is less clear. Spinal cord injury is a moderate predictor of low BMD and fracture.

Screening Tests

The clinical diagnosis of osteoporosis is made in two ways: occurrence of an osteoporotic fracture or BMD more than 2.5 standard deviations (T-score, −2.5) below that of a young, healthy population, as measured by dual-energy x-ray absorptiometry (DEXA). However, because DEXA is expensive and not available everywhere, other screening tests are sometimes used to evaluate BMD.

SELF-ASSESSMENT

The osteoporosis self-assessment screening tool uses a person's age and weight to determine his or her risk for osteoporosis (risk score = [weight in kilograms – age in years] × 0.2). There is no accepted threshold for a positive risk score, although various studies have used scores ranging from −1 to 3. Two studies of Asian men showed that a risk score of −1 has a sensitivity of 70 to 90 percent and a specificity of 70 percent to diagnose osteoporosis. A study of U.S. veterans showed that a threshold of 3 has a sensitivity of 93 percent and a specificity of 66 percent. However, when the threshold was reduced to 1, the sensitivity decreased to 75 percent and the specificity increased to 80 percent.

CALCANEAL ULTRASONOGRAPHY

Calcaneal ultrasonography, in which an ultrasound probe is placed on the heel to measure BMD, is not sufficiently sensitive or specific to screen for osteoporosis. A T-score of −1.0 has a sensitivity of 75 percent and a specificity of 66 percent to diagnose osteoporosis; when the T-score is decreased to −1.5, the specificity increases to 78 percent, but the sensitivity decreases to 47 percent. Calcaneal ultrasonography can moderately predict fragility fractures in men.

CALCANEAL ULTRASONOGRAPHY PLUS DEXA

A combination of calcaneal ultrasonography with confirmatory DEXA testing has been suggested. However, the benefit of combined testing versus either test alone to predict fractures is unknown.

Recommendations

Physicians should periodically perform an individualized assessment of risk factors for osteoporosis in older men (strong recommendation; moderate-quality evidence). The appropriate age at which to begin risk assessment is unknown. However, by age 65 years, at least 6 percent of men have DEXA-determined osteoporosis, so risk factor assessment before this age is reasonable.

Physicians should order DEXA testing for men at increased risk of osteoporosis who are candidates for drug therapy (strong recommendation; moderate-quality evidence). BMD measurement with DEXA is the reference standard for diagnosing osteoporosis in men, and men who are at increased risk for osteoporosis are candidates for DEXA. No studies have evaluated the optimal interval for repeat DEXA screening.