Obesity linked to disability in women with osteoarthritis - Advances & Insights

What the news
Leslie J. Crofford, MD means for you

Leslie J. Crofford, MD

Study highlights risk of disability
The Johns Hopkins study is important because it re-emphasizes the link between obesity, gender, arthritis and disability. It’s one of the very few that has looked over a long period of time at people who started without limitations then went on to become disabled, as well as the factors mediating that change. Female gender and body mass were the two factors that were identified in this study.

“Arthritis is an important complication of obesity that isn’t widely discussed or recognized.”

It’s very important for women in particular to understand that obesity not only has consequences for conditions like hypertension and diabetes. Arthritis is an important complication of obesity that isn’t widely discussed or recognized. Disability and functional limitations have a huge impact on quality of life.

Kentucky ranks second in the entire nation in the prevalence of arthritis, according to the CDC, just behind West Virginia. Of the one million Kentuckians with arthritis, half are limited in their physical abilities by the disease.

Not just a disease of the old
Arthritis isn’t just a disease of old age. Many studies show that it most often starts in the 40s. In fact, many elderly people do not have severe arthritis. Preliminary data from the Kentucky Women’s Health Registry, which tracks health trends among Kentucky women, showed that nearly 25 percent of the respondents have arthritis. Of that group, only 16 percent were over the age of 60.

In my practice, I see people who are in their 30s. If you injure your knee in sports as a teenager, you can develop severe osteoarthritis of the knee in your 40s or earlier.

Two good points for patients we can take from this current study are:
• If you maintain a normal body weight, you’re less likely to have problems with osteoarthritis, and
• If you already have arthritis, lowering your body mass may prevent your arthritis from limiting your physical function.

When body mass index is over 30, there’s a big change in how much body mass affects your mobility. A BMI of 25 to 30 is still classified as overweight, but once it’s over 30, a person needs to make some changes.

Treatment for osteoarthritis
Besides the knees and hips, osteoarthritis affects the neck, lower back, thumb joint, fingers and big toe. Pain, swelling and stiffness are the key symptoms. Diagnosis is through medical and physical exams and sometimes X-rays.

When patients come to me with knee or hip arthritis, I counsel them about maintaining normal body weight and exercising. The transmitted force of your weight on your knees increases four times when you’re standing. So if a person weighs 200 pounds, the force of weight on their knees when they’re standing is almost 800 pounds.

Walking, biking, any kind of repetitive contraction of the quadriceps is very useful exercise. There are also assistive devices that help unload weight from the joints–for example, canes and built-up handles that protect the fingers from a tight grip. Aquatic exercises are also useful because water takes the stress off joints.

To treat patients for pain, we often use Tylenol®, which has low toxicity. Anti-inflammatory drugs and intermittent injections are also good. Ice, heat and certain topical creams are useful as well.

Use of glucosamine
One of the most highly studied therapies for pain is the dietary supplement glucosamine. The National Institutes of Health funded a very large study, comparing the use of glucosamine for the treatment of knee osteoarthritis with a nonsteroidal anti-inflammatory drug (NSAID). Overall, glucosamine wasn’t any more effective than the placebo, while patients taking the NSAID experienced significant pain relief. However, studies done in Europe, where glucosamine is regulated, have shown it is effective.

I tell my patients who are interested in glucosamine to do their own “clinical trial,” writing down your assessment of pain in a particular joint on a scale of 0 to10, with 10 being the most painful. Take the supplement for a month then reassess your pain. If there’s a 2.0 decline, it’s probably worthwhile to continue taking it.

"A major focus now is on finding...changes that begin in the cartilage early on before they show up on an X-ray."

New research
Osteoarthritis is very hard to study because it takes so long to evolve. Unfortunately, there are no disease-modifying drugs for it at this time, but that’s an area of very important investigation. A major focus now is on finding biomarkers, changes that begin in the cartilage early on before they show up on an X-ray. That would be helpful in identifying drugs that both prevent the process and also prevent adverse clinical outcomes such as disability.

I would encourage women to participate in the Kentucky Women’s Health Registry (www.kywomensregistry.com) because that will allow us to do studies similar to the one at Johns Hopkins. The registry is a longitudinal epidemiological study of women. We’ll be able to do exactly the same kind of evaluations, looking at incidences of osteoarthritis and the factors in our state that contribute to this disease. end

Dr. Crofford is chief of the division of rheumatology and professor of internal medicine at UK College of Medicine. She is also the Gloria W. Singletary Chair and director of the UK Center for the Advancement of Women’s Health

Obesity linked to disability in women with osteoarthritis

Arthritis is the leading cause of disability among adults in this country, limiting the activities of 16 million people, according to the Centers for Disease Control. There are more than 100 forms of this disease, but the most common is osteoarthritis, which causes the breakdown and eventual loss of cartilage of the joints.

To determine how this disability occurs in older women and its relationship to excess weight, researchers at the U.S. National Institute on Aging and the Johns Hopkins Medical Institutions in Baltimore used data from the Women’s Health and Aging Study II. Their analysis included 199 women with knee or hip osteoarthritis who initially had no problems in mobility and 140 women who showed no signs of osteoarthritis. Participants were age 70 to 79.

Women with osteoarthritis were
2.5 times more likely to develop limitations in mobility and difficulty performing activities of daily living.

Over a period of six years, scientists studied both groups to see if the women with osteoarthritis were more prone to disability than those who did not have the disease and whether the osteoarthritis developed before or after decreased mobility. Along with the impact of excess weight, they also looked at the effects of pain and low quadriceps strength on disability. The findings were reported in the April 2006 issue of Arthritis Care & Research.

Study findings
Previous studies have shown that obesity is associated with knee pain and the progression to osteoarthritis. However, the Johns Hopkins study is one of the few to examine how excess weight contributes to disability in arthritic patients.

The authors acknowledged that the study may be limited by the fact that X-rays were not available for all of the women. In addition, the lengthy interval between observations made it more difficult to
pinpoint the extent of lower extremity limitations prior to the development of disability.

The findings are particularly relevant in light of the growing numbers of elderly, overweight women.

But the findings are particularly relevant in light of the growing numbers of elderly, overweight women. “From 1960 to 1999, the prevalence of overweight adults increased from 44 percent to 61 percent, and the prevalence of obesity doubled from 12 percent to 27 percent and has reached epidemic proportions in the U.S.,” the authors wrote.

They continued, “The trends towards earlier onset of obesity observed between 1991 and 1998 would predictably translate into a higher proportion of adults who could develop painful symptoms and mobility difficulty at an earlier age.”

By the year 2030, the Centers for Disease Control and Prevention (CDC) estimates 25 percent of Americans will have been diagnosed with arthritis. Regular exercise can decrease pain, improve function and delay the progression of osteoarthritis, but only about 37 percent of adults with arthritis exercise regularly.

For more information, or to make an appointment with a UK HealthCare physician, please call UK Health Connection at (800) 333-8874