UCSF Research: High & Low Levels of Activity Accelerate Knee Cartilage Degeneration
A new study conducted at UCSF and presented today at the annual Radiological Society of North America (RSNA) meeting confirms that both too much and too little physical activity can accelerate the degeneration of knee cartilage in middle-aged adults. For the study, our research team looked at the changes in knee cartilage among 205 patients, aged 45 to 60, over four years with the use of MRI-based T2 relaxation times.
MRI-based T2 relaxation times allow for analysis of the biochemical and molecular composition of cartilage, and as a result, can be used to track knee cartilage degeneration. This measurement (= the T2 value) allows to study the water content and collagen structure of the cartilage, which are important for cartilage function and stability; with degeneration the water content increases and collagen structure deteriorates. Knee cartilage degeneration is an early and telling sign for knee osteoarthritis, which, according to data from the Centers for Disease Control and Prevention, may affect up to one in two U.S. adults by age 85. Further, approximately 67 million Americans over the age of 18 are projected to have physician-diagnosed arthritis by 2030.
The results of the research, which measured T2 values throughout the knee at baseline, two and four year intervals, revealed that participants partaking in frequent high-impact activities, such as running, experienced the highest levels of cartilage degeneration, and thus, a higher risk for osteoarthritis development. However, those who had very low levels of activity also had accelerated progression of T2 values. This suggests that there may be an optimal level of physical activity to preserve the cartilage.
Additionally, the study highlighted the potential use of MRI-T2 relaxation times as an early indicator of cartilage degeneration. Standard MRI shows cartilage defects that are irreversible. But, these new cartilage measurements give information on a biochemical level, thus potentially detecting changes at an early stage while possibly still reversible.
In closing, the study confirms that individuals at a higher risk for osteoarthritis, due to family history, obesity or prior knee injury, can reduce their risk for cartilage degeneration by maintaining a healthy weight and avoiding risky or high-impact physical activity. Lower impact sports, including walking and swimming, are essentially more beneficial than higher impact sports, like running or tennis, for those at risk for osteoarthritis.
To learn more about osteoarthritis research at UCSF, please click here.