Smoking Impacts Knee Osteoarthritis

Men who have osteoarthritis of the knee and smoke have greater cartilage loss and more severe pain than men who do not smoke, according to study results published online in the Annals of the Rheumatic Diseases. The study, led by a Mayo Clinic rheumatologist, examined the symptomatic knees of 159 men. The men were monitored for up to 30 months. Their knees were scanned using MRI and their pain level was scored. Of the 159 men, 19 were active smokers at the beginning of the study. On average, the 19 men smoked 20 cigarettes a day for about 40 years.

The study results revealed that the smokers were more than twice as likely to have significant cartilage loss than the non-smokers. According to researchers, reasons that may explain the link between smoking and cartilage loss include:

• Smoking may disorder the cells and deter cell production in cartilage.
• Smoking may raise levels of toxins in the blood, contributing to cartilage loss.
• Smoking may increase carbon monoxide levels in the blood, affecting blood oxygenation, which could impede cartilage repair.

The smokers also had higher pain scores than the non-smokers. The researchers suggest, since cartilage does not have pain fibers, increased pain may not be caused by cartilage loss. However, smoking may impact other structures in the knee or may have an effect on pain perception.

Related Resources:

• How Smoking Affects Arthritis
• More About Knee Pain
• Osteoarthritis Screening Quiz
• Test Your Knowledge: Osteoarthritis

_{Photo by Paola Fontana (iStockphoto)}