Five-year intervals okay for retesting bone density
NEW YORK (Reuters Health) - Repeat bone density testing in middle-aged and older adults can be delayed for intervals of up to 5 years if they don't have risk factors for bone loss, findings from a Canadian study suggest.
Dr. David Goltzman at Royal Victoria Hospital in Montreal and colleagues examined rates of change in bone mineral density (BMD) as a function of age among a random sample of men and women aged 25 to 85 years.
Their results suggest that between ages 25 and 40, bone mass is relatively stable in women. BMD begins to fall between ages 40 and 44, with the greatest rate of decline between ages 50 and 54, followed by a slower decline.
Bone loss starts earlier in men, the investigators report, with a steady rate of decline first observed between 25 and 39 years of age.
A second stage of accelerated bone loss at the hip occurs in old age, beginning after age 70 in women and after age 65 in men.
"Although current guidelines recommend that measurements of bone density be repeated once every 2 to 3 years, our data suggest that, at this rate of testing, the average person would exhibit changes well below the margin of error," even during periods of peak bone loss, Goltzman and colleagues state.
They therefore suggest that repeat measurements of bone density "could safely be delayed for intervals of up to 5 years" unless the efficacy of a bone-building therapy is being monitored or there are additional risk factors for bone loss, such as use of steroids.
SOURCE: CMAJ: Canadian Medical Association Journal 2008.