Why you need to use the same bone density machine for follow-up testing

Bone density testing machines are sort of a double-edged sword. They can provide a rough idea of what’s happening with your bone mass over the years, but they also have various limitations. In this blog I will show you a case example of one serious limitation that will remind us to always compare apples to apples!

There are two major types of bone density machines — one is the Hologic device and the other GE Lunar. While both devices attempt to measure bone density in “grams per cubic centimeter,” the test results from these two machines are not comparable. As a result of this technicality, it’s very important that any follow-up bone mineral density testing be done on the same brand of machine as used before.

In this blog we’ll see from Lilly how changing from one bone density machine to the other can yield very inaccurate, even frightening results. You might want to take a few minutes to hear Lilly explain how she narrowly avoided demoralization and mistreatment due to a change in bone density machines. You’re guaranteed to learn a lot from her story.

Lesson from Lilly’s Story — Always Use the Same Machine!

Lilly came to the Center for Better bones at age 73. She had a history of losing bone and was diagnosed with osteoporosis of both the spine and the hip. She did not have access to functional medicine or progressive doctors and really didn’t even have a lifestyle focused on exercise or special health activities. However, she had a feeling in her heart that there was a better way to maintain bone health and she was wary of the bone drugs her doctors kept recommending. After seven years in our Better Bones, Better Body ® program, Lilly optimized her pH, took all the bone-building nutrients as we suggested,  attended to quieting her mind and reducing stress, and walked daily for exercise.  Lilly’s efforts paid off and she had great success.

Over those seven years that she worked with us, Lilly gained bone density in both the spine and the hip  while most women her age would have lost between 3 and 7% of their bone mass.

Lilly was, however, almost demoralized and derailed by an unknown switch in bone density testing machines.  As it occurred, Lilly went to a new doctor, a rheumatologist, to discuss arthritic pain in her hands and since she was due for her next bone density test, he suggested she just do the bone density in his office. Given that this was during the COVID pandemic, Lilly thought it a good idea, as she could avoid an extra medical visit. The thing she did not realize, however, was that this doctor had a different type of bone density testing machine from the one that she had used over the past years. The difference in machines made all the difference in the world.

This new doctor told her that her spinal bone loss was serious and that she should consider bone drugs. Totally distressed Lilly sent us her new bone density test, and after talking with us, she on her own went back to her family doctor and managed to obtain a second bone density test. The second test was done on the same machine as she had used over the past seven years, comparing apples to apples, and sure enough, Lilly was doing just fine. Actually, in the last two years she had not lost bone mass, but gained 3.25% in her spine, 9.4% in the total hip and 11.9% in the neck of the hip!

So, the lesson here is to keep track of which bone density machine was used on your previous test and try to use the same type of machine. Should you switch machines remember that the measurements from the Lunar device come back about 6% higher than those from the Hologic device.