Obesity and Aging Genes Might Play a Big Role in Arthritis
Researchers and doctors have known that obesity and aging can lead to injured knees due to the added pressure that the body places on the cartilage and the slow deterioration of these tissues in older people. The condition, osteoarthritis occurs when the cartilage severely breaks down, resulting in pain, swelling, and stiffness in the joints, making movement difficult. New research looked into the roles of the genes responsible for obesity and aging and their relationship to the development of arthritis. The researchers from the Washington University School of Medicine in St. Louis found that these genes can contribute to osteoarthritis.
"We know there's a mechanical relationship. People who are obese have increased pressure and force on the knee joint. And older people have more wear and tear on the joints. But we wanted to see whether something else is going on that may accelerate the risk for osteoarthritis," the researchers stated.
The study followed 68 people who underwent recent surgeries to repair or remove a torn meniscus, which is the cartilage found in the knee. The meniscus is responsible for cushioning the area between the shinbone and thighbone, and a tear in the meniscus have been linked to an increased risk for developing osteoarthritis later in life. The lead researcher and sports medicine specialist, Robert H. Brophy, MD stated that 50 percent of people who suffer a meniscus tear could develop arthritis within 10 to 20 years based on previous studies. Brophy, who is an associate professor of orthopedic surgery and M. Farrooq Rai, PhD, a postdoctoral research scholar in orthopedic surgery looked at 28 different genes linked to obesity and aging in these patients. They also observed the activity of the secretion of inflammatory substances in meniscus tissue.
They found that five genes, four related to aging and one related to obesity, were acting abnormally in the presence of the torn meniscus tissue. The researchers reported that the obesity-related gene in overweight patients had lower activity levels. The activity levels of the four aging genes in older patients were also lower. These lower levels might be contributing to the higher levels of inflammation in the tissue, which can lead to osteoarthritis. This study is important in finding specific biological markers of osteoarthritis, which would help doctors prescreen patients for their risks in developing the disease.
The study was published in the International Journal of Obesity.