Cigarette Smoking and Knee Damage

Cigarette smoking more than doubles the risk of developing knee damage, according to research published in the Annals of the Rheumatic Diseases. The study looked at the effects of smoking on cartilage loss and knee pain in men with osteoarthritis. More than 10 million Americans, most over the age of 45, have osteoarthritis of the knee. It occurs when the cartilage between two bones becomes worn down, and the bones begin to rub against each other. This causes stiffness, swelling, and pain, which limits movement and can lead to disability. Evidence has suggested that cigarette smoke damages cartilage function but this is the first study to examine the effect of smoking on knee damage and pain. Over a 30-month period, 158 male smokers with osteoarthritis underwent MRI scans of their knee cartilage and were assessed for pain. They found that the smokers had twice the likelihood of cartilage loss than the nonsmokers and suffered increased pain. The researchers suggest that smoke in the bloodstream may affect cell growth in knee cartilage, with the increase in carbon monoxide causing damage to knee tissue and leading to increased pain. It is also possible that smoking may simply lower pain tolerance. Larger studies and the inclusion of women will likely provide more accurate results, but it is clear from this early report that smoking does damage knee cartilage. This study sheds more light on the damaging effects of smoking and may convince some smokers to quit.