NIKI MOHAN: Dr. Metzger, what's the difference between osteoporosis and osteoarthritis?
ALLAN METZGER, MD: They are completely different diseases, but unfortunately patients don't understand that. Osteoarthritis is something that occurs with trauma or aging and it's a problem with cartilage. The cartilage degenerates and loses its ability to protect between joints and patients get arthritis or spurs or a pain syndrome.
Osteoporosis effects the bone itself, not the cartilage, and is most importantly, unfortunately, a silent disease. There is loss of the integrity and strength and power of the bone itself and most patients don't have symptoms until they get a fracture.
NIKI MOHAN: How can an osteoporotic spinal fracture feel similar to arthritis, or does it?
ALLAN METZGER, MD: It may rarely if you have an older woman, for example, who has osteoarthritis in the spine. On top of it, she may get a fracture because of osteoporosis, and low back pain may come on gradually andmay feel like osteoarthritis. Most of the time when you have a fracture, you know it. It's an acute, severe debilitating sudden illness, episode, whereas osteoarthritis is often more gradual, even though it may be in the same population or the same low back location.
NIKI MOHAN: How common is it for patients to confuse the two and do they often?
ALLAN METZGER, MD: Patients confuse it because they have a sense that osteoporosis gives them pain. In general, patients confuse it and unfortunately once in a while physicians are not aware enough about osteoporosis to put that in a differential diagnosis of how they approach the patient.
NIKI MOHAN: Now what if someone comes in the office and they say, "My back's hurting. I've had this back pain here." How does that feel different from osteoporotic pain?
ALLAN METZGER, MD: It generally does. If someone comes in with a back pain, for example, a woman who's 40, who's still having her periods, 99 percent of the time it will not be osteoporosis or a fracture because theoretically they still have estrogen and theoretically they don't have osteoporosis unless they haveother risk factors.
Women who are, say in their 70's, who have not been on estrogen, who present with sudden terrible back pain, I'm always concerned about a disk or a fracture.
NIKI MOHAN: What are those risk factors? Let's run through them.
ALLAN METZGER, MD: The important risk factors are related to genetics. We know there is a high risk in families. If a mother has osteoporosis and/or a fracture, there is a higher risk for the daughter or even the son. Other risk factors are clearly related to menopause -- early menopause or late onset of periods --so estrogen deficiency is a risk factor.
Another risk factor could be different medicines. If you're given too much cortisone or too much thyroid replacement, accidentally by your physician, that can affect the bones.
Lifestyle issues are also critical. If you don't exercise, if you're so to speak a couch potato, we know that that's not good for the bones. If you're exercising moderately, that's good. But we've also learned that too much exercise -- somebody who is a weekend warrior every day of the week and loses body fat and loses body muscle and loses body weight --that person, who has a relative loss of her periods, sometimes is at risk.
People who don't have enough calcium in their diet or don't take supplemental calcium or don't drink milk, can have a risk factor.
NIKI MOHAN: Let's talk about the age at which osteoporosis becomes a threat. Now you talk a lot about the aging process. What about young people? Are young people at risk also?
ALLAN METZGER, MD: Young people are at risk. They generally have what we call secondary osteoporosis or osteopenia -- thin bones, but not in the realm of fracture. This is generally related to lifestyle issues. Anorexia, bulimia, too much exercise with the loss of periods, being on cortisone or too much thyroid hormone, or not having calcium in the diet.
Once in a while we see young people who smoke or drink too much, whether it be alcohol or caffeine. These can be risk factor issues in younger people as well.
As the population ages, men and women, the disease starts occurring with a certain frequency. Women get this illness in their 60's and 70's, men often 10 years later. And the frequency is about five to one. Many, many more women get this illness than men.
NIKI MOHAN: What about caffeine consumption? A lot of people have one, two, maybe three cups of coffee in the morning.
ALLAN METZGER, MD: We have the sense that overt caffeine ingestion, too much caffeine, multiple cups of something a day does not do well with bone formation. A little bit of caffeine is probably okay.
NIKI MOHAN: What about race? Now white women and Asian women?
ALLAN METZGER, MD: Yes. White women andAsian women have the greatest problem with osteoporosis. We have a sense that this is not lifestyle but it's genetics -- certain genetic markers that have not been defined yet. Certain parts of the gene, even though we've mapped most of the human genome, we haven't localized the defect -- why Caucasians have a greater risk than black women or intermediate risk like American Indians?
NIKI MOHAN: What kind of tests do you use to detect osteoporosis?
ALLAN METZGER, MD: The most important test is a thing called a DEXA or a QCT, a specific measurement of the mass or density of bone, a bone density test. And most physicians, hospitals, and X-ray units use what's called a DEXA (D-E-X-A). This specifically measures the boney architecture mass and exactly how much calcium is in a very solid or strong bone. An X-ray is a little inefficient.
If you see osteoporosis on an X-ray as an incidental finding, say in a yearly chest X-ray, in a 60-year-old woman, this may be related to the loss of at least 40% of calcium in the bone. You need that much loss to detect it on an X-ray.
NIKI MOHAN: How long does this take and does it hurt?
ALLAN METZGER, MD: The DEXA is probably the best test you can have and recommend. The patient doesn't get undressed. There's no embarrassment. There's no stigma to getting the test. It's painless. It takes five minutes on some of the newer machines. The nice advantage is you can measure different body parts. You can measure the spine and the hips which are the most important areas for fracture and it gives you a risk-relationship to how low the density is and kind of points us in the direction of what we need to do to help the patient.