The Osteoarthritis Prevention Study

This large multicenter clinical trial is testing whether a combined program of dietary weight loss, exercise, and long-term weight maintenance can prevent knee osteoarthritis from developing in women who are at high risk due to obesity. Participants are women aged 50 and older with obesity (BMI of 30 or above) who do not yet have knee osteoarthritis and have little or no knee pain, and the primary measure of success is whether the intervention reduces changes visible on knee MRI scans over 48 months. Women must be ambulatory, free of active cancer, and able to change their eating and activity habits to participate, among other criteria. Participation involves following a structured diet and exercise program for 4 years and attending regular clinic visits for MRI scans, function tests, and questionnaires. This summary was prepared to help patients understand the study in plain language.