High Body Mass Index Is Associated With Increased Diurnal Strains in the Articular Cartilage of the Knee
Article first published online: 24 SEP 2013
Copyright © 2013 by the American College of Rheumatology
Arthritis & Rheumatism
Volume 65, Issue 10, pages 2615–2622, October 2013
How to Cite
Widmyer, M. R., Utturkar, G. M., Leddy, H. A., Coleman, J. L., Spritzer, C. E., Moorman, C. T., DeFrate, L. E. and Guilak, F. (2013), High Body Mass Index Is Associated With Increased Diurnal Strains in the Articular Cartilage of the Knee. Arthritis & Rheumatism, 65: 2615–2622. doi: 10.1002/art.38062
- Issue published online: 24 SEP 2013
- Article first published online: 24 SEP 2013
- Accepted manuscript online: 1 JUL 2013 03:37PM EST
- Manuscript Accepted: 10 JUN 2013
- Manuscript Received: 21 MAR 2013
- NIH. Grant Numbers: AR-50245, AR-055659, AR-063325, AG-15768, AR-48182, AR-48852
- National Football League Charities
- Arthritis Foundation
Obesity is an important risk factor for osteoarthritis (OA) and is associated with changes in both the biomechanical and inflammatory environments within the joint. However, the relationship between obesity and cartilage deformation is not fully understood. The goal of this study was to determine the effects of body mass index (BMI) on the magnitude of diurnal cartilage strain in the knee.
Three-dimensional maps of knee cartilage thickness were developed from 3T magnetic resonance images of the knees of asymptomatic age- and sex-matched subjects with normal BMI (18.5–24.9 kg/m2) or high BMI (25–31 kg/m2). Site-specific magnitudes of diurnal cartilage strain were determined using aligned images recorded at 8:00 AM and 4:00 PM on the same day.
Subjects with high BMI had significantly thicker cartilage on both the patella and femoral groove, as compared to subjects with normal BMI. Diurnal cartilage strains were dependent on location in the knee joint, as well as BMI. Subjects with high BMI, compared to those with normal BMI, exhibited significantly higher compressive strains in the tibial cartilage. Cartilage thickness on both femoral condyles decreased significantly from the AM to the PM time point; however, there was no significant effect of BMI on diurnal cartilage strain in the femur.
Increased BMI is associated with increased diurnal strains in articular cartilage of both the medial and lateral compartments of the knee. The increased cartilage strains observed in individuals with high BMI may, in part, explain the elevated risk of OA associated with obesity or may reflect alterations in the cartilage mechanical properties in subjects with high BMI.