Criteria Used in the Diagnosis of Osteoporosis

Peter L. Salgo, MD: We hear these 2 terms, and you hear them all the time. They’re in popular magazines. They’re also in the medical literature. There’s low bone density, and then there’s osteoporosis. What is the difference between low bone density and osteoporosis?

Thomas P. Olenginski, MD, FACP, CCD: That’s a good question. Low bone density means bone density that is below the T-score WHO [World Health Organization] fracture risk, on its 2.5 definition. It’s important to realize that patients with low bone density fracture, particularly patients on steroids, and low bone density and other risk factors increase their risk of developing the clinical syndrome of osteoporosis. So osteoporosis, as you’ll hear this evening, is many things and it’s a continuum. It could be a T-score, it could be somebody who’s had a hip fracture, or it could be somebody with low bone density and other risks who’s at risk for a fracture where we want to intervene before something else happens.

Peter L. Salgo, MD: Let me take a swipe at this. Low bone density is a number that you measure. It’s a laboratory result. Osteoporosis is a clinical syndrome. Is that fair?

Andrea J. Singer, MD, FACP, CCD: Absolutely. And I wanted to emphasize, or re-emphasize, something that Tom said. It really is a continuum of disease. We get hooked on numbers sometimes. So the World Health Organization has helped in terms of that definition, which is a bone density definition. But when we look at and treat patients in the real-world setting, we’re taking into account a number of factors. Bone density is part of it. The lower the bone density, the greater the risk for fracture, but we need to look at clinical risk factors in all kinds of other scenarios.

Peter L. Salgo, MD: So it would be fair to say to a patient, “Look, I measured your bone density. It’s really low. You’re at risk for osteoporosis,” as opposed to saying, “Your bone density is low. Therefore, you’ve got it.”

Andrea J. Singer, MD, FACP, CCD: You can define osteoporosis by the T-score alone, but we shouldn’t stop there. There are other people for whom their bone density may not meet criteria for osteoporosis, but they may have what we call a clinical diagnosis of osteoporosis because we take into account the bone density number and then the rest of the individual picture.

Peter L. Salgo, MD: OK, if it is a clinical syndrome, then there are symptoms associated with it. What are the symptoms of osteoporosis?

Claire Gill: There are a lot of symptoms with osteoporosis. Sometimes it can be asymptomatic. Oftentimes patients don’t realize they have osteoporosis until they actually fracture, and that’s what makes it confusing to patients, I think. They feel fine. They think, “I’m doing my normal activities. I’m OK,” and then they go to their doctor and they get a T-score that shows them that they’re actually at a very high risk of fracture, and it becomes confusing.

Peter L. Salgo, MD: What about comorbidities? What goes along with osteoporosis?

Thomas P. Olenginski, MD, FACP, CCD: Just about everything, or maybe nothing.

Peter L. Salgo, MD: Oh, that’s really helpful.

Thomas P. Olenginski, MD, FACP, CCD: Thank you. It is the silent thief. The comorbidities that I’m concerned about today include type 2 diabetes, which has a lot of risk; rheumatoid arthritis, which independently increases the risk of osteoporosis; and COPD [chronic obstructive pulmonary disease]. Patients with COPD who smoke or don’t smoke are at risk. I am also concerned about chronic kidney disease as well as any type of inflammatory disease or any other illness that weakens the patient, maybe makes them less active. But essentially, we see many patients with either low bone density and other risk factors who have the clinical syndrome, who’ve had a fracture, or patients with a T-score who have high blood pressure, high cholesterol, and it’s really the gambit. There’s no question that the comorbidities make the treatment decisions and the discussions with the patient a little more difficult.

Claire Gill: One thing that often confuses patients is height loss. That’s one of the symptoms of osteoporosis. If you’ve lost more than an inch of height within a year, that’s a potential symptom and it’s going to be something that should be addressed. Many people think as we grow older, we get shorter, and that it’s a normal part of aging. There is some height loss that comes with aging, but significant height loss, like over an inch in that amount of time, is a symptom of osteoporosis.

Peter L. Salgo, MD: It’s funny you mention that, because when I take histories from patients I usually take their height. They always say, “Well, you know, I’m shrinking.”

Claire Gill: Right.

Peter L. Salgo, MD: And these are usually people over 65, 70 years old. So you’re telling me that some of those people should be worked up for osteoporosis?

Claire Gill: Absolutely.

Andrea J. Singer, MD, FACP, CCD: The reason that’s so important is height loss may be an indication of a spine or vertebral fracture that has gone unnoticed.

Peter L. Salgo, MD: Got it.

Andrea J. Singer, MD, FACP, CCD: About two-thirds of vertebral fractures don’t initially present with symptoms. Or, they may present with symptoms but back pain is common. So people think, “I had a little back pain, it’s probably muscular,” and they don’t think much about it.

Peter L. Salgo, MD: It was a fracture all along and now they’re unsure.

Andrea J. Singer, MD, FACP, CCD: They thought it was a fracture all along. Exactly.

Peter L. Salgo, MD: The other thing you mentioned is that a number of these immunologic diseases are often treated with steroids. The first thing that crossed my mind was, where’s the confluence here? Sometimes it’s the disease. But I’m thinking sometimes it’s the therapy?

Thomas P. Olenginski, MD, FACP, CCD: Yes, it’s the therapy a lot of times, but it’s also the inflammatory mediators that have effects on bone, and effects on muscle, and effects on wellness and activity. There are still a lot of things we don’t know about the illnesses. So again, Lupus is not necessarily an independent risk factor, but clearly patients with Lupus, bad Lupus, need more glucocorticoids and other immunomodulatory therapies. They clearly break bones. The same thing can be said about patients who have inflammatory bowel disease.

Peter L. Salgo, MD: Yes, I was going to say that you put them on prednisone and the ball game is a different ball game.