Do All Forms of Obesity Increase the Risk of Knee OA?


Obesity increases the risk for knee osteoarthritis (OA), but does where you carry body fat matter? Some research has suggested that people with big bellies are more likely to develop severe knee OA and require joint-replacement surgery, so an international team of arthritis experts decided to investigate whether the location of body fat influences risk.

The team identified 161 people who didn’t have knee OA, but were at risk for the condition either because they were obese or had other factors, such as a history of knee injuries. Each participant had his or her body mass index (BMI, an indicator of body fat) calculated and abdominal and thigh fat measured. These same numbers were gathered for a group of 186 healthy control subjects.

Four years later, X-rays were used to determine which participants had developed knee OA. The researchers found that having a big belly or flabby thighs raised one’s risk for knee OA, but where fat was located on the body didn’t make any difference: Simply having a high BMI put participants at greater risk. The findings were published in August 2018 in Osteoarthritis and Cartilage.

The burden of excess body fat contributes to knee OA by stressing the joints and wearing down cartilage, but scientists now believe that inflammatory chemicals produced by fat cells damage joints, too. Regardless, the message is the same: Keeping your weight down can help prevent knee OA and minimize its symptoms.