OSTEOARTHRITIS (OA) is the most common form of arthritis, affecting over 40 million people in Europe alone. Obesity, a risk factor, results in patients being twice as likely to develop knee OA. Understanding the aetiology can help to improve the treatment of patients with OA. Recently, at the Osteoarthritis Research Society International (OARSI) 2022 World Congress, radiologists and their teams shared their latest findings, which showed that weight gain could worsen the damage of knee OA, as demonstrated through biomedical imaging.
The study aimed to evaluate the role of weight gain and loss in patients with hip or knee OA, specifically assessing radiological features. Data from approximately 3,000 individuals was utilised, and patients with OA were divided into three groups: patients with 5% weight gain, patients with no weight change, and patients with 5% weight loss.
Results revealed that patients who lost more than 5% of their weight during the 4-year period were more likely to have a better Kellgren–Lawrence grade compared with patients that did not gain or lose weight. On the other hand, the individuals who gained weight were linked to a 29% increased risk for medial joint space narrowing compared with the control group. Additionally, patients who gained weight were 34% more likely to experience frequent knee pain.
Interestingly, there were no radiographic differences of the hip between patients who gained weight, patients who lost weight, and the control group. Gabby Joseph, a Specialist in Radiology and Biomedical Imaging, University of California, San Francisco, USA, questioned this finding during the congress: “Why are there differing effects of weight change in the knee versus the hip?”
Joseph added that these differences between knee and hip OA could be due to multiple factors, such as the different loading patterns of the hip and knee joints and differences in cartilage thickness. The speakers acknowledged the limitations of their research, notably the retrospective study design, which made it impossible to follow-up with patients or find out why they gained or lost weight.
In conclusion, there is a clear association between weight gain and worsening knee OA; however, the link between weight gain and hip OA was less evident. This could be more apparent in a future study that is conducted in real-time.