When it comes to weight loss in overweight and obese adults with knee osteoarthritis, more is better

Wake Forest University researchers, led by professor of health and exercise science Stephen Messier, previously showed that overweight and obese individuals with knee osteoarthritis can reduce pain by 50% and significantly improve function and mobility with a 10% or more weight loss over an 18-month period. The investigators’ latest findings, which are published in Arthritis Care & Research, reveal that a 20% or more weight loss has the added benefit of continued improvement in physical health-related quality of life and a 25% reduction in pain and improvement in function compared to 10-19.9% weight loss.

“A 10% weight loss is the established target recommended by the National Institutes of Health as an initial weight loss for overweight and obese adults,” said Messier, lead author of the study.

The results come from a secondary analysis of diet-only and diet plus exercise groups in the Intensive Diet and Exercise for Arthritis (IDEA) randomized controlled trial. A total of 240 overweight and obese older community-dwelling adults with pain and knee osteoarthritis were divided into four groups according to weight loss achieved over an 18-month period: less than 5% (<5% group), between 5 and 9.9% (≥5% group), between 10 and 19.9% (≥ 10% group), and 20% and greater (≥20% group).

Stephen Messier

The researchers found that the greater the weight loss, the better participants fared in terms of pain, function, 6-minute walk distance, physical and mental health-related quality of life, knee joint compression force, and IL-6 (a marker of inflammation). Also, when comparing the two highest groups, the ≥20% group had 25% less pain and better function than the ≥ 10% group, and significantly better health-related quality of life.

“Substantially greater weight loss, achieved safely, has the added benefit of improved quality of life, and clinically important reductions in pain and improvement in function,” Messier said.

Obesity is a health issue worldwide and a major and modifiable risk factor for many of the more than 250 million adults with knee osteoarthritis.

For those who may avoid exercise because of knee osteoarthritis, Messier said over 25 years of research is clear: “Exercising will reduce your pain by 25%. Every time you take a step, your whole body weight is focused on your knee. By lowering your body weight, you can reduce the load on your knee and in turn reduce your pain. If you slowly increase your exercise time pain should be reduced and mobility increased.”

Maintaining mobility in older adults is crucial and mild to moderate exercise combined with weight loss is the best prescription.

Full Citation: “Initial Weight Loss for Overweight and Obese Knee Osteoarthritis Patients: Is More Better?” Stephen P. Messier, Allison Resnik, Daniel P. Beavers, Shannon L. Mihalko, Gary D. Miller, Barbara J. Nicklas, Paul DeVita, David J. Hunter, Mary F. Lyles, Felix Eckstein, Ali Guermazi, and Richard F. Loeser. Arthritis Care & Research; Published Online: June 18, 2018 (DOI: 10.1002/acr.23608).