Siblings Often Share Knee Osteoarthritis
British Study Shows Double the Risk for Siblings of People With the Condition
Aug. 11, 2004 -- Brothers and sisters of people with osteoarthritis in their knees are twice as likely to develop the same condition, report British researchers.
The first large sibling study on knee osteoarthritis shows that genetics may contribute to osteoarthritis.
Osteoarthritis is the most common type of arthritis, which causes a degeneration of joints and loss of joint cartilage. The destroyed joint cartilage leads to inflammation, bone pain, and limited joint mobility. The knee joint is the most common body part affected by osteoarthritis. Many factors increase the risk of osteoarthritis including the normal aging process, trauma, and obesity. Some studies have indicated that genetics may also play a role in the development of this type of arthritis.
The study conducted in Nottingham, England by author R.L. Neame, MD, of the academic rheumatology department of Nottingham's City Hospital, analyzed data from 490 knee-osteoarthritis patients needing total knee replacement surgery and 737 of their brothers and sisters.
The researchers looked to see whether genetics contributed to the development of osteoarthritis of the knee.
All of the siblings were at least 40 years old and were full-blood relatives of the people with knee osteoarthritis.
For comparison, researchers also included 1,729 people in the Nottingham area who had consulted doctors about knee pain.
While race was not part of the study, all of the siblings were white, as was 99% of the comparison group.
Taking knee X-rays of the siblings and members of the comparison group, researchers looked for signs of structural knee damage caused by osteoarthritis.
"Siblings had double the risk of knee osteoarthritis," write the researchers. That finding held true even after osteoarthritis risk factors such as age, smoking, gender, and weight were taken into account.
Brothers were slightly more likely to have the condition than sisters.
The study "adds to the growing body of evidence that there is a genetic contribution" to common forms of osteoarthritis, write the researchers.