PROJECT SUMMARY / ABSTRACT
Osteoarthritis (OA), the leading cause of disability among adults, is without a cure and is associated
with significant comorbidities. OA ranks as the third most common diagnosis for hospital inpatient stays
with 1.25 M per year, with the knee the most commonly affected weight-bearing joint. We address
knee OA disease prevention in adult females because prevention of OA is preferable to treatment,
females are affected at nearly twice the rate as males, and to date interventions designed to slow or
stop knee OA progression have failed. Dietary weight loss, with and without exercise, has level 1
evidence of effective treatment for adults with knee OA and overweight and obesity. Reduced
degenerative cartilage changes are also associated with weight loss, making it a possible preventive
therapy for people at risk for knee OA. The objective of this Phase III, multi-site (Boston, MA, Chapel
Hill, NC, Broward County, FL, Sydney, Australia, and Winston-Salem, NC) randomized clinical trial is to
establish the efficacy of an intervention of dietary weight loss, exercise, and weight-loss maintenance
for knee OA prevention. We will establish efficacy in structural, symptomatic, and mechanistic
outcomes compared to attention control, and determine the cost-effectiveness of this non-
pharmacologic, non-surgical intervention in preventing incident knee OA in adult females aged ≥ 50
years with obesity and no or infrequent knee pain, a cohort at high risk for knee OA.
Participants will be 1,230 ambulatory, community dwelling females with obesity (BMI ≥ 30
kg/m2), and aged ≥ 50 years. Structural and symptomatic eligibility will be determined at the individual
knee level. The eligible knee will have no radiographic (Kellgren Lawrence (KL) score ≤ 1) and no MRI
knee OA with no or infrequent knee pain (< 15 days/month) in the same knee. The primary aim is to
compare the effects of a 48-month intervention of dietary weight loss, exercise, and weight-loss
maintenance to an attention control group in preventing the development of structural (MRI) knee OA
using the MRI OA Knee Score (MOAKS). Secondary aims will determine the intervention effects on the
Knee Injury and Osteoarthritis Outcome Score (KOOS total), KOOS pain, mobility (6 minute walk
distance), and health-related quality of life (SF-36). Mechanistic secondary outcomes include knee joint
compressive forces as a measure of joint loading, IL-6 as an inflammatory measure, and weight loss
and exercise self-efficacy. We will also establish the cost-effectiveness of this intervention.
This study is significant in that it will test a critically needed primary prevention intervention of
dietary weight loss, exercise, and weight-loss maintenance for females at risk for knee OA.