Osteoarthritis (OA) is the complete medical name for the condition generally referred to as “arthritis.” The most common joint disease in humans and all vertebrate animals, osteoarthritis is a universal affliction: virtually everyone who lives past age 75 has it to some degree. Nearly 50 percent of the population suffers from osteoarthritis by age 65. Osteoarthritis hits hard on the hardest working joints: the knees, the hips, the hands, and fingers. The weight-bearing joints and the spine are especially vulnerable. It is a fundamental fact of life that as we age, our joints lose their youthful flexibility and range of motion. Movement eventually becomes difficult and painful as we slowly, year by year, become less supple and stiffer. Osteoarthritis is characterized by progressive, degenerative changes in cartilage structure. The proteoglycans break down, losing their ability to form tight clusters. The water content of cartilage increases. Chondroitin sulfate shortens in length. Cartilage loses the ability to repair itself and develops clefts and crevices that eventually extend down to the underlying bone. The end result is weak, stiff, and deformed joints.
Previous research has suggested that estrogen may influence the development of osteoarthritis. The purpose of a recent study was to evaluate the association of two common gene types (aromatase and estrogen receptor genes) and their influence on the development of osteoarthritis. The study included 3,098 patients with severe osteoarthritis and 2,381 controls from 4 centers in Spain and the United Kingdom. Researchers measured gene expression from femoral bone RNA samples taken from the participants. It was found that both genotypes were associated with the risk of severe osteoarthritis of the large joints of the lower limb. These results appear to confirm that estrogen activity may influence the development of osteoarthritis.1
1 Riancho JA, Garcia-Ibarbia C, Gravani A, et al. Common Variations In Estrogen-Related Genes Are Associated With Severe Large Joint Osteoarthritis: A Multicenter Genetic And Functional Study. Osteoarthritis Cartilage. Apr2010.