Wilson Lin BS, Presenter: Nothing to Disclose

Hamza Alizai MD, Abstract Co-Author: Nothing to Disclose

Gabby B. Joseph, Abstract Co-Author: Nothing to Disclose

Waraporn Srikhum MD, Abstract Co-Author: Nothing to Disclose

Charles E. McCulloch, Abstract Co-Author: Nothing to Disclose

Thomas M. Link MD, PhD, Abstract Co-Author: Research Grant, General Electric Company

Michael C. Nevitt PhD, Abstract Co-Author: Nothing to Disclose

John A. Lynch PhD, Abstract Co-Author: Nothing to Disclose

The relationship between physical activity and the evolution of osteoarthritis (OA) remains unclear. Cross-sectional studies have shown that very low and high levels of exercise may be associated with higher cartilage T2 relaxation times than mild levels of exercise. The purpose of this study was to analyze the association between physical activity levels and the evolution of early degenerative cartilage changes in the knee, measured using T2 relaxation times over a period of 4 years in normal individuals and those with risk factors for OA.

We included 205 subjects aged 45-60, BMI 19-27 kg/m2, no knee pain at baseline (WOMAC score of zero), and a Kellgren-Lawrence score of less than 2 in the right knee at baseline, from the Osteoarthritis Initiative Incidence and Normal cohorts. Physical activity was scored using the Physical Activity Scale for the Elderly (PASE) questionnaire, which was averaged over a 4-year time period and categorized into tertiles. T2 values of articular cartilage were measured at the patella, medial/lateral femur and medial/lateral tibia of the right knee in multi-echo SE sequences at baseline, 2- and 4-year visits. A mixed model linear regression, adjusted for age, sex, and BMI, and including random effects for individual was used for statistical analysis.

All compartments in the knee showed significant T2 progression over the 4-year period. T2 progression was higher in the highest tertile than in the mid-tertile at the medial tibia (2.8±0.3 vs. 2.0±0.3, P=0.04), the patella (4.1±0.5 vs. 3.1±0.5, P=0.02), and the average T2 of all knee compartments combined (2.5±0.2 vs. 2.0±0.2, P=0.03). T2 progression was also higher in the lowest tertile than in the mid-tertile in all compartments, but results were not significant.

High levels of physical activity were associated with greater progression of cartilage T2 measurements in asymptomatic, middle-aged individuals, suggesting accelerated cartilage matrix biochemical degeneration over time. Low levels of physical activity may exert a similar effect on cartilage, a pattern consistent with cross-sectional analysis, but longitudinal associations in our cohort were non significant.

High physical activity levels were associated with accelerated cartilage degeneration (as judged by T2 relaxation measurements over 4 years) and may be considered a risk factor for osteoarthritis.

Lin, W, Alizai, H, Joseph, G, Srikhum, W, McCulloch, C, Link, T, Nevitt, M, Lynch, J, High Levels of Physical Activity are Associated with Greater Cartilage Degeneration over a Period of 4 Years as Assessed with T2 Relaxation Time Measurements – 3T MRI Data from the Osteoarthritis Initiative.  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12031237.html