Obesity and Osteoarthritis

Obesity Can Cause Arthritis Pain of the Hips. Sebastian Meckelmann/E+/Getty Images

The aches and pains of osteoarthritis can be challenging to deal with, and obesity can make them much worse. In fact, just a little weight loss can often result in an improvement in joint pain.

What Is Osteoarthritis?

The medical term “arthritis” literally means “joint inflammation.” There are many kinds of arthritis, such as rheumatoid arthritis and psoriatic arthritis, but osteoarthritis is most common, and refers to the arthritis that affects most of us as we age due to the wear and tear our joints experience over years of use.

According to the Arthritis Foundation, 27 million Americans have osteoarthritis, and obesity is a common risk factor.

Obesity and Osteoarthritis

Patients with obesity commonly report joint pain, especially of weight-bearing joints such as the knees and hips. Some experts have estimated that approximately 35% of people with osteoarthritis are also obese, and this adds a significant burden both in terms of functional status (getting around, being able to do everyday activities) and clinical status (of the arthritis disease process itself).

Studies have shown a significant association between increased weight and osteoarthritis of the knee and of the hip, and still more research has looked at how weight-loss therapy in obese older adults can improve physical function. Researchers note that one result of weight loss is improved mobility, and a good part of this is due to less mechanical stress on the joints, with fewer symptoms of arthritis.

One analysis showed that body mass index (BMI) and knee osteoarthritis are directly correlated; as BMI increases, so does the risk of knee osteoarthritis, in an “almost exponential” fashion, according to the study authors.

Thus, obesity can both contribute to the development of arthritis as well as worsen existing arthritis.

There is also evidence that one of the obesity-related hormones, leptin, may play a role in arthritis; research on this process is ongoing.

Weight Loss Improves Arthritis

One large, community-based study found that patients with obesity or overweight who were able to lose more than 5% of body weight, even when final BMI remained high, had significant improvement in knee osteoarthritis. The greatest benefit was seen in those who lost at least 10% of body weight; in these patients, the symptoms of knee arthritis improved by approximately 40%. This means that one does not have to lose weight all the way down to one's ideal weight to see improvement in arthritis symptoms; improvement will still be seen with a modest degree of weight loss.

Another study in overweight and obese older adults with osteoarthritis of the knee found that weight loss combined with exercise was better than either exercise or diet alone in improving mobility.

Experts are in agreement that weight loss can improve the symptoms of osteoarthritis, and weight loss is thus a powerful tool in the treatment of arthritis, especially when combined with regular exercise.


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