Magnetic resonance images show that how people lose weight has an impact on slowing down knee cartilage degeneration, according to a study presented at RSNA.
Researchers from the United States investigated cartilage degeneration and joint abnormalities in overweight and obese subjects who maintained stable weight and who lost weight via differing regimens. A total of 760 subjects (295 men and 465 women) were recruited from the Osteoarthritis Initiative. All had a BMI of greater than 25kg/m2 and mild to moderate osteoarthritis or risk factors for the disease. The subjects were divided into two groups of 380 each, one group that lost weight, and a control group of 380 patients that lost no weight. The weight-loss group was further divided by weight loss method: diet and exercise, diet alone, and exercise alone. The subjects all underwent right knee MR imaging to quantify knee osteoarthritis at the beginning of the study, at 48 months, and at 96 months.
The researchers evaluated T2 relaxation time changes of cartilage composition, including laminar and texture analysis as well as morphological knee abnormalities, assessed with Whole-Organ-Magnetic-Resonance-Imaging-Scores (WORMS).
The results showed progression of cartilage WORMS was significantly lower in the weight loss group compared to controls over 96 months. Subjects with weight loss showed significantly less T2-value increase in the bone layer of all compartments compared to the controls with stable weight, suggesting less cartilage degeneration over 96 months in the subjects with weight loss compared to their controls. Rates of increase in cartilage T2 averaged over all compartments were lowest in the diet and diet and exercise groups compared to the stable weight group. Weight loss through exercise alone showed no significant difference in change of T2 over 96 months compared to subjects with stable weight.
“These results add to the hypothesis that solely exercise as a regimen in order to lose weight in overweight and obese adults may not be as beneficial to the knee joint as weight loss regimens involving diet,” lead author, Alexandra Gersing, MD, from the Department of Radiology and Biomedical Imaging at the University of California, San Francisco, said in a release.