In obesity and knee osteoarthritis, weight loss is a big win

Weight loss of more than five percent produced clinically meaningful improvements in knee osteoarthritis, even when final body mass index remained high, a large, community-based study has shown.

For those patients who lost 10 percent body weight in the study, knee osteoarthritis symptoms improved by about 40 percent consistent with the recent IDEA (Intensive Diet and Exercise for Arthritis) trial findings.

“There is a strong dose-response relationship between percentage weight loss and improvement in knee pain, function, symptoms, sport or recreation, and quality of life,” said at the World Congress on Osteoarthritis.

They described the study as the first to examine the dose-response relationship between changes in body weight and knee osteoarthritis in a real-world, community setting.

The researchers evaluated 1,383 Australians who fulfilled the American College of Rheumatologists criteria for knee osteoarthritis (OA) and were enrolled in the structured, remotely delivered “Healthy Weight for Life” knee and hip osteoarthritis management program. It integrates intensive weight loss as a component of tailored interventions, with the aim of achieving a seven percent -10 percent body weight loss over 18 weeks, explained a consultant rheumatologist at the University of Colombo, Sri Lanka.

The program uses a partial very-low-calorie diet, portion management tools and devices, written healthy eating advice, and lifestyle education together with targeted telephone, e-mail, and text-message motivation and support. All participants were given the same strength, balance, and mobility exercise tools, instruction and support.

At baseline, 81.7 percent of participants were obese, the average body mass index (BMI) was 34.4kg/m² and the mean Knee injury and Osteoarthritis Outcome Score (KOOS) pain and function subscale scores were 56.3 and 59.5. The cohort was 71 percent female and had an average age of 64 years.

At 18 weeks, there was a clear and significant incremental improvement in KOOS subscales across the weight-loss categories, with the greatest improvements in those losing at least 10 percent body weight.

The investigators next examined the dose-response of weight loss, compared with differences in pain and function. For this analysis, the 2.5 percent or less weight-loss category was set as the reference. The dose-relationship between weight loss and improvements in pain and function persisted, even after controlling for baseline age, gender, weight, height, and KOOS, said at the meeting, sponsored by the Osteoarthritis Research Society International.