Got Knee Pain From Arthritis? Stop Smoking!

Osteoarthritis (OA) is the most common form of arthritis. It is
due to premature wearing away of cartilage, the gristle that
cushions the ends of long bones in the joint.

Known risk factors for knee OA include a history of trauma, a
family history of the disease, certain metabolic conditions, and
obesity.

A recent study has confirmed the suspicion that smoking has
another detrimental effect on health. It can worsen the
prognosis of men who have osteoarthritis of the knee. The study,
performed by researchers from Boston University School of
Medicine and the Mayo Clinic and published in the January 2007
issue of the Annals of the Rheumatic Diseases, followed 159 men
with knee osteoarthritis for 30 months. Nineteen of the men were
smokers.

After the researchers adjusted their study results for age,
body mass index (a measure of weight in relation to height) and
baseline cartilage scores, they found that the smokers were at
increased risk of cartilage loss and experienced more pain than
the men who did not smoke.

"Our findings also suggest smoking plays a role in the
progression of symptomatic knee osteoarthritis and, therefore,
is a modifiable risk factor with important public health
implications," Dr. David Felson, director of the Clinical
Epidemiology Research and Training Unit and professor of
medicine and public health at Boston University School of
Medicine.

The researchers could not pinpoint why smoking was associated
with knee pain. It is not likely due to cartilage loss, since
cartilage does not have pain fibers, Felson stated.

"Instead, smoking may have direct effects on other articular
structures mediating knee pain or may modify the threshold for
musculoskeletal pain among smokers," he said.

Further study is needed to investigate the effects of smoking
on knee osteoarthritis, the researchers added.

One hypothesis is that smoking may "turn on" proinflammatory
mechanisms in osteoarthritis. This may occur as a result of the
interaction of nicotine or other ingredients and predisposing
genetic markers a patient may possess.

(Interestingly, cigarette smoking also is a risk factor for
rheumatoid arthritis and the turning on of proinflammatory
cytokines is felt to be cause).

It is critical for patients to understand the need to reduce
any risk factors for arthritis they may have. For instance, if a
patient already has a strong family history of osteoarthritis,
they may want to avoid cigarette smoking altogether.

Add this potential medical problem to the long list of things
that smoking aggravates.

About The Author: Nathan Wei, MD FACP FACR is a rheumatologist
and Director of the Arthritis and Osteoporosis Center of
Maryland. He is a Clinical Assistant Professor of Medicine at
the University of Maryland School of Medicine. For more info:
http://www.arthritis-treatment-and-relief.com/arthritis-treatment.html