New York: People who smoke may face an increasing risk of knee pain than non-smokers.

David Felson and researchers at Boston University School of Medicine and the Mayo Clinic studied 159 men with knee osteoarthritis for 30 months. Nineteen of the men were smokers, reported health portal HealthDay.

The study looked at their age, body mass index (BMI) a measure of weight in relation to height and baseline cartilage. They found that smokers were at increased risk of cartilage loss and experienced more pain than men who did not smoke.

The researchers, however, could not pinpoint why smoking was associated with knee pain. It is not likely due to cartilage loss, since cartilage  a type of dense connective tissue does not have pain fibers, Felson explained.

"Instead, smoking may have direct effects on other articular structures mediating knee pain or may modify the threshold for musculoskeletal pain among smokers," said the study published in the January issue of the journal Annals of the Rheumatic Diseases.