Osteoarthritis in weight bearing joints: higher susceptibility in obese people
Our joints bear the brunt of our body weight. So when we are obese it can place undue strain on the joints. The knee joint is the most common site for osteoarthritis to develop. However, in obese people even the base of the thumb has been known to get osteoarthritis.
10 pounds overweight?
It has been found that people who are overweight by just 10 pounds will place 30 to 60 pounds force on the knee joint. The pressure increases with every step taken while walking. The excess force can accelerate the fragmentation of cartilage which keeps our joints supple. In general, an activity like walking places 3-6 times the natural body weight force on the knee joints.
The presence of osteoarthritis in the hands of obese people could be a symptom of circulatory systemic disorder. In cases like thumb osteoarthritis the carpometacarpal joint gets affected. However, thumb osteoarthritis and its relation to obesity has not been researched extensively. Studies indicate that symptoms include reduced thumb mobility as well as swelling and tenderness in the carpometacarpal joint.
Commonly affected joints
While the most common joint affected by osteoarthritis is the knee, other joints in the neck, hips, hands as well as the back can also be affected. The extent of osteoarthritis in these joints is dependent on how much pressure is placed on these joints.
In obese men the risk of developing knee osteoarthritis increases four-fold while in obese women the risk is five-fold. It has also been found that people whose body weight lies in the highest quintile are 10 times more prone to knee osteoarthritis as compared to those on the low quintile bracket.
How to assess being overweight?
There are three factors that an overweight person can determine which bracket of the quintile he or she falls in.
The first is the Body Mass Index or BMI which is calculated by dividing weight by height and squaring the result. A BMI assessment needs to be done once in two years for even normal weight persons.
The second factor is the circumference of the waist. A waist size exceeding 40 inches in the case of men and 35 inches in women indicates being overweight. This is true even if the BMI falls within 25 to 34.
The third factor is the risks that accentuate the problem such as cholesterol, blood pressure etc.
Weight loss alleviates pain
It has been found that even moderate amounts of exercise can dramatically reduce the pain of osteoarthritis. In the Framingham study it was found that people with BMI higher than 25 experienced a decrease in knee osteoarthritis after weight loss. Women of normal height undergoing weight loss found that with every 11 pound loss in weight, the risk of knee osteoarthritis was decreased by 50% or more. It has also been found that a regular and moderate amount of exercise is crucial to reducing the risk of knee osteoarthritis.