Because changes in bone mineral density occur fairly slowly in most women, “there is some controversy as to what time point following an initial baseline bone mineral density test should a repeat test be performed,” says Dr. Matthew Drake, a researcher in radiology at the Mayo Clinic College of Medicine in Rochester, Minn.
If the test is repeated too quickly, it may be hard to tell if any measured change really represents bone loss, Drake, who wasn’t involved in the study, says by email. Waiting at least two to three years before a repeat test may be better for many patients, he says.
“There are several potential reasons why bone mineral density could decrease after osteoporosis therapy is started,” Drake adds. “These include failing to continue taking the medication as directed; a lack of adequate calcium and vitamin D intake,” or a decrease in weight bearing activities.
