Obesity Alone Doesn't Cause Knee Arthritis

Reported October 05, 2009

(Ivanhoe Newswire) -- Obesity is considered one of the strongest risk factors for osteoarthritis, but a new study in mice suggests a hormone may play an important role.

Researchers studied mice deficient in leptin -- a protein hormone that is responsible for regulating appetite and metabolism -- to find out if obesity would increase chances of developing osteoarthritis of the knee. While the mice showed a three-fold increase in body mass and 10-fold increase in body fat, they did not show symptoms of the arthritis.

"It was surprising that knee osteoarthritis was not present given the severity of obesity in the leptin-impaired mice," lead researcher Farshid Fuilak, Ph.D., was quoted as saying.

When the mice reached 10 to 12 months of age, researchers measured their body fat content, took blood samples and analyzed their knee joints to look for degeneration.

Experts say the study implies leptin, which actually increases in humans as body fat increases, could be directly involved in the development of osteoarthritis.

Source: Arthritis & Rheumatism, 2009