Quotes of the Day
The first sign is often a twinge in your knee or your back or some
stiffness at the base of your thumb. Or maybe you're getting out of the
car and a sharp pain shoots down your leg from your hip to your calf.
"Nothing serious," you think. "I must have just strained something. I'm
too young to have arthritis."
Think again. If you are within even shouting distance of middle age,
chances are you have osteoarthritis, a degenerative disorder in which
the cartilage—the natural shock absorber that cushions the insides
of your joints—begins to break down. Doctors used to think of it as
a disease of old age, but they now believe that this form of arthritis,
the most common of about 100 types, begins its relentless, initially
painless course when you're still in your 30s, 20s or even younger. Most
of the time you won't suspect anything is wrong until you're in your 40s
or 50s and begin to feel those telltale twinges, signs that the disorder
may be starting to affect your bones. By then the damage has been done,
and even the best treatments can't do much more than ease the pain and
try to maintain the status quo in what are already degenerating joints.
In the U.S., estimates show there are 20 million people with arthritis, a number projected to grow to 40 million by 2020. Getting a statistical measure across Asia is more difficult. And other, more deadly diseases tend to grab more attention. But when you consider the estimates that do exist for Asia's arthritis victims—150 million in India, at least 65 million in China, 10 million in Japan, 1.6 million in Taiwan—along with unanimous testimony from doctors that the number of arthritic patients is rising significantly, it creates a picture that, for Asia's nations and health-care budgets, looks a lot like arthritis itself: painful in the short term, potentially crippling down the line.
What's more, many would-be patients don't know that something can or needs to be done, or they don't have enough information to make an informed (and safe) decision about their care. "Arthritis is a huge problem in our society," says Dr. Koh Wei Howe, president of Singapore's Rheumatoid Arthritis Society. "There are many sufferers out there who are not aware of the available treatments. Some don't even recognize that they have arthritis."
There exists, however, the possibility of some relief amid all the aches and pains. Researchers are paying a lot more attention to osteoarthritis these days. They have discovered that what they thought was a fairly straightforward mechanical breakdown of the joints is a much more complicated process with lots of component parts. Although this means that patients hoping for a quick fix are likely to be disappointed, scientists are starting to gain the kind of insights that can lead to more effective treatments and better strategies for heading off trouble before it begins.
How complex a process are we talking about? Doctors used to think that cartilage was the beginning, middle and end of the osteoarthritis story. Now they know that cartilage is important, but so is everything that surrounds it—muscles, bones, tendons and ligaments. The damage caused by wearing ill-fitting shoes, suffering a football injury or spending day after day stooped over in a field can certainly give rise to arthritic joints. But the worst problems often stem from basic differences in the body's biochemical makeup. For example, some people's cartilage seems to resist damage better than others'. In addition, researchers have discovered an array of biochemical messages that are traded between bones, muscles and other parts of the body and play a key role in keeping joints healthy. "Ultimately, we think it's the biochemical approach that's going to solve the riddle of arthritis," says Dr. Mitchell Sheinkop, an orthopedic surgeon at the Rush—Presbyterian—St. Luke's Medical Center in Chicago. "Someday you may pop a pill and your cartilage will continue to grow, but that's 10 years away—at least."
Until then, what doctors would like to have is some kind of test that will identify people in the earliest stages of osteoarthritis before too much damage has occurred. That way their treatments might stand a better chance of arresting the degenerative process before disability sets in. Unfortunately, conventional X rays, which give very detailed pictures of bone, don't provide very good images of cartilage. And researchers haven't yet discovered any biological markers in the blood that reliably tell them, "Hey, this person's cartilage is starting to fall apart. Do something!"
To understand the latest insights and where they might be leading, it helps to know a little bit about how a joint is put together, and there's no better place to start than with the cartilage. Like so many tissues in the body, cartilage is composed mostly of water. Indeed, you can think of it as a damp sponge. The spongy part contains several important components, including the chondrocytes—cells that generate new bits of cartilage—and various molecules that give the "sponge" its structure and help hold it together.
With every step we take, our moving body puts pressure roughly equal to three times our weight on the knees and hips. As that pressure is distributed across those joints, cartilage is compressed, absorbing most of the load. And, as you might expect with something that resembles a damp sponge, water is squeezed out of the cartilage into the space between the bones. Once the pressure is released, the water flows back into the cartilage, carrying with it nutrients that were picked up from the synovial fluid, which fills the joint. This constant fluid exchange is critical to maintaining healthy, pliable cartilage and explains why joint-moving exercises—such as walking—help delay the progress of osteoarthritis.
Sometime between ages 40 and 55, the activity of the chondrocytes starts slowing down and the cartilage takes longer and longer to replenish itself. As the cushion of cartilage grows progressively thinner, the bones begin to grind against one another. This is a normal consequence of aging, but aging isn't the only culprit. Something as simple as falling on an icy sidewalk or putting on some extra weight can increase your risk of osteoarthritis. Anything that puts extra stress onto the joints will wear out the cartilage that much faster. Now the first wrinkle: "It appears that not all cartilage is created equal," says Dr. Roland Moskowitz, president of the Osteoarthritis Research Society International in Washington, D.C. Ankles, for example, bear the same loads as knees and hips. Yet most people, unless they're ballet dancers, don't get osteoarthritis of the ankle. Similar discrepancies exist in non-weight-bearing joints as well. The wrist, for instance, is much less prone to osteoarthritis than the joint at the base of the thumb. It could be that ankles and wrists have some mechanical advantage that protects them from osteoarthritis. But preliminary evidence suggests that the real advantage, at least for ankles, is biochemical: there is something in their composition that allows them to bear greater loads and respond to changes in the joint without breaking down.
Some evidence for this comes from related research on bones. Most people think of bones as inert objects whose only job is to keep our bodies from collapsing into a puddle of flesh. But bones are actually quite active tissues, constantly building and rebuilding themselves from the inside out. If you break a bone, the body produces repair proteins that direct cellular activities as the bone knits itself together. When investigators take these so-called osteogenic proteins and sprinkle them on lab samples of damaged cartilage, the cartilage begins to repair itself. "Now here comes the interesting part," says Dr. Klaus Kuettner, professor of biochemistry at Rush—Presbyterian—St. Luke's. "The ankle joint responds better than the knee joint to osteogenic proteins." Is that why the ankle rarely gets osteoarthritis? "We don't know," he says, "but it's a hint in that direction."
Another hint comes from the observation that women with strong, healthy bones—the kind least susceptible to the brittleness of osteoporosis—are at greater risk of developing osteoarthritis. Again, doctors suspect a complex interplay of mechanical and biochemical factors. Healthy bones can support heavier loads. They also tend to replace old bone cells with new bone cells at a pretty fast clip. But somehow the biochemical signals responsible for the bone's increasing turnover rate trigger even greater damage to the cartilage. Or is it the other way around? Is it damaged cartilage that gets the process started by sending aberrant signals to the bone? "At this point, it would be a mistake to fight bitterly over whether osteoarthritis starts in the bones or cartilage, because in the end there may be different forms of the disease," says Dr. Bjorn Olsen, a cell biologist at Harvard University. "In some cases, it may start in the bone. In others, it might start in the cartilage."
In a 10-year study of American families that include members who have developed osteoarthritis in their 40s and 50s, Olsen's group has identified at least three genetic variations that make the cartilage of these patients more susceptible to overloading. Other scientists have found at least a dozen cartilage-disrupting enzymes that appear to be overactive in osteoarthritis. Yet even the interaction between bones and cartilage doesn't tell the whole story. You also need to take into account the ligaments—those tough bands of tissue that connect bones to bones—and the muscles that surround and stabilize the joints. Ligaments can get stretched or torn, and muscles can atrophy from underuse, disrupting a joint's finely tuned mechanism.
Take, for example, the quadriceps, the large muscles on the front of the thighs that help raise and lower the legs. "It's common knowledge that patients with osteoarthritis of the knee will have weakness in the quadriceps," says Dr. Kenneth Brandt, a rheumatologist at Indiana University in Indianapolis. For a long time, physicians assumed this was because their patients' pain prevented them from exercising. But five years ago, Brandt and his colleagues began studying a group of 400 elderly people living in central Indiana and discovered, much to their surprise, that weakness in the quadriceps in some cases preceded the advent of osteoarthritis.
It makes sense. The stronger the muscles, the greater the load they take off the joint, thus limiting damage to the cartilage. Brandt's group is trying to determine whether healthy seniors who strengthen their quads by doing exercises with elastic bands can delay, or possibly prevent, the disabling consequences of osteoarthritis in their knees. Professor Mohd Farooque, former head of orthopedics at the All India Institute of Medical Sciences in New Delhi, says this is particularly applicable in Asia: "In the West, arthritis is seen much more in the hip, but here it is much more in the knee. This is because we sit like Buddha, we squat on the toilet, we kneel to pray, and it puts the knee under extreme stress. If it's a daily activity, the muscles and joints adjust. But if people, say, don't pray as often as they might, then it can do a lot of damage."
However the arthritic process gets started, the damage to the joint eventually begins to grow. That's when the body's immune system gets into the act. White blood cells rush into the joint and release destructive proteins that chew up the pieces of damaged tissue. This so-called inflammatory process, which is often but not necessarily accompanied by swelling, works well when the body needs to fend off an acute attack, say, from invading viruses or bacteria. But when the problem is chronic, as in osteoarthritis, the white blood cells might overreact, repeatedly releasing so many "mopping up" proteins that even healthy tissue is laid waste. In rheumatoid arthritis, the immune-system response is particularly aggressive.
So what can you do? The first step for most patients is to try to get some immediate relief. About 15% don't seem to experience inflammation; for them, over-the-counter painkillers like acetaminophen (Tylenol) are often all that's necessary to control their symptoms. Things become more complicated when inflammation is involved. Western standbys like aspirin or ibuprofen are pretty good anti-inflammatories, but long-term use can trigger dangerous side effects such as internal bleeding. Traditional remedies abound as well: acupuncture, massage, hot-spring baths, herbal ointments and more targeted (and dubious) palliatives such as sour plum juice (in Taiwan) or deer horn and tiger's penis (in China). Newer drugs, such as COX-2 inhibitors Vioxx and Celebrex, tend to be more effective but aren't yet available in all Asian countries.
Some researchers believe there is too much emphasis on drug treatments for osteoarthritis. "There are other things that can improve symptoms as much as pills," says Indiana University's Brandt. Losing weight as little as 4.5 kilos can make a difference, for example, as can strengthening the muscles that surround a joint. Certain exercises, such as tracing circles in the air with the arms, have also proved helpful at keeping the joints from stiffening and losing mobility. Many arthritis sufferers swear by the dietary supplements glucosamine and chondroitin. Preliminary studies suggest they might relieve pain, but the jury's still out on whether they actually promote the growth of new cartilage.
Sometimes surgery is unavoidable. Each year doctors in the U.S. perform 270,000 knee replacements and 170,000 hip replacements. In Asia, countries like Singapore and Japan—where medical care is sophisticated and patients are relatively wealthy—lead the way. But the number of surgeries performed is rising all across Asia.
No single approach works best for everyone. As with any chronic
condition, there are always some things you can't control. But there's
still a lot you can do for yourself. That's the lesson Kazuko Hayashi, a
71-year-old housewife from the city of Kamakura, west of Tokyo, has
learned. She has osteoarthritis in both knees. When the pain started, at
the age of 60, she figured it was a by-product of her youthful days of
competitive volleyball and swimming. "I thought it was an old people's
disease," she says, "but I see many younger people having the same
problem." Her doctor recommended knee replacement surgery, but she's
hoping to avoid it, opting instead for three sessions a week of
electromagnetic therapy and massages. For exercise, she walks in a
swimming pool, and she's trying to shed six kilos. Hayashi is also
waiting for the day researchers know enough about what triggers
osteoarthritis to come up with more effective treatments. "There is a
surgery to remove wrinkles; there must be a good treatment being
developed for arthritis. I should live long and wait for it." Everybody
else should pay attention to those twinges. 
- Christine Gorman and Alice Park
- Arthritis is crippling Asia, but new treatments could help save your joints