The Intensive Diet and Exercise for Arthritis (IDEA) trial: design and rationale

BMC Musculoskelet Disord. 2009 Jul 28;10:93. doi: 10.1186/1471-2474-10-93.

Abstract

Background: Obesity is the most modifiable risk factor, and dietary induced weight loss potentially the best nonpharmacologic intervention to prevent or to slow osteoarthritis (OA) disease progression. We are currently conducting a study to test the hypothesis that intensive weight loss will reduce inflammation and joint loads sufficiently to alter disease progression, either with or without exercise. This article describes the intervention, the empirical evidence to support it, and test-retest reliability data.

Methods/design: This is a prospective, single-blind, randomized controlled trial. The study population consists of 450 overweight and obese (BMI = 27-40.5 kg/m2) older (age > or = 55 yrs) adults with tibiofemoral osteoarthritis. Participants are randomized to one of three 18-month interventions: intensive dietary restriction-plus-exercise; exercise-only; or intensive dietary restriction-only. The primary aims are to compare the effects of these interventions on inflammatory biomarkers and knee joint loads. Secondary aims will examine the effects of these interventions on function, pain, and mobility; the dose response to weight loss on disease progression; if inflammatory biomarkers and knee joint loads are mediators of the interventions; and the association between quadriceps strength and disease progression.

Results: Test-retest reliability results indicated that the ICCs for knee joint load variables were excellent, ranging from 0.86 - 0.98. Knee flexion/extension moments were most affected by BMI, with lower reliability with the highest tertile of BMI. The reliability of the semi-quantitative scoring of the knee joint using MRI exceeded previously reported results, ranging from a low of 0.66 for synovitis to a high of 0.99 for bone marrow lesion size.

Discussion: The IDEA trial has the potential to enhance our understanding of the OA disease process, refine weight loss and exercise recommendations in this prevalent disease, and reduce the burden of disability.

Trial registration: NCT00381290.

Publication types

  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biomarkers / blood
  • Body Mass Index
  • Combined Modality Therapy
  • Disability Evaluation
  • Exercise Therapy*
  • Humans
  • Inflammation Mediators / blood
  • Knee Joint / pathology
  • Knee Joint / physiopathology*
  • Magnetic Resonance Imaging
  • Middle Aged
  • Mobility Limitation
  • Obesity / complications*
  • Obesity / physiopathology
  • Obesity / therapy
  • Osteoarthritis, Knee / diet therapy
  • Osteoarthritis, Knee / etiology
  • Osteoarthritis, Knee / physiopathology
  • Osteoarthritis, Knee / therapy*
  • Pain / etiology
  • Pain / prevention & control
  • Pain Measurement
  • Predictive Value of Tests
  • Prospective Studies
  • Recovery of Function
  • Reproducibility of Results
  • Research Design
  • Severity of Illness Index
  • Single-Blind Method
  • Time Factors
  • Treatment Outcome
  • Weight Loss
  • Weight-Bearing

Substances

  • Biomarkers
  • Inflammation Mediators

Associated data

  • ClinicalTrials.gov/NCT00381290