Effect of calcium tablets on interpretation of lumbar spine DXA scans.

Undissolved calcium (Ca) tablets in the gastrointestinal tract at the time of a dual-energy X-ray absorptiometry (DXA) scan could conceivably affect the accuracy of the lumbar spine bone mineral density (BMD) determination. We studied phantoms and volunteers to determine the effect of Ca tablets overlying bone, Ca tablets in the soft-tissue field, and Ca tablets overlapping both bone and soft tissue. For L1-4, a 500-mg Ca tablet taped to the phantom surface or the skin of volunteers resulted in

What are the criteria by which a densitometric diagnosis of osteoporosis can be made in males and non-Caucasians?

Osteoporotic fractures are not rare in men or non-Caucasian women. However, for these groups, there is no consensus densitometric definition of osteoporosis. As is the case in Caucasian women, low bone mineral density (BMD) is associated with increased fracture risk among men and non-Caucasian women; thus, a densitometric definition of osteoporosis seems feasible. Reaching agreement on criteria for diagnosing osteoporosis in men and non-Caucasians was among the goals of the International Society for Clinical Densitometry Position Development Conference held in July 2001. To this end, the conference recommendation for males is that osteoporosis be defined as a BMD T-score of -2.5 or below the young normal mean for men. Since the relationship between BMD and fracture risk may differ between men and women, it is recommended that T scores in men continue to be derived using a male normative database. Similarly, for non-Caucasians, the recommendation is to diagnose osteoporosis at or below a T-score of -2.5. However, given the difficulty in defining race or ethnic groups, a dearth of data, and their conflicting nature correlating BMD with fracture risk in different ethnicities, it is recommended that a uniform normative database (not adjusted for race) be utilized in the United States for T-score derivation in non-Caucasians. Note that these are current clinical recommendations, which may change as additional data accumulate. Furthermore, there was agreement that the following individuals should have their bone density measured: anyone (male or female, regardless of race) with prior fragility fractures or with conditions widely recognized to increase the risk of bone loss and fracture (such as hypogonadism, corticosteroid treatment, hyperparathyroidism, alcohol abuse, anticonvulsant use, and prior gastrectomy); women on long-term hormone replacement therapy; and in the absence of these conditions, women age 65 and older (regardless of race) and men age 70 and older.