Smokin’ Joints

Why men who smoke are at lower risk of joint replacement surgery.

Posted Oct 03, 2012

A study published a few months back in Arthritis & Rheumatism concluded that men who smoke are less likely than nonsmokers to require artificial hip or knee replacement, and those who smoke the longest have the lowest risk of joint replacement surgery. In fact, the risk was a stunning 50% lower—even after factoring in the competing risk of death, which was higher with higher tobacco consumption.

The researchers focused on body weight, physical activity levels, and smoking, looking at over 11,000 men in the following age groups: 65 to 69, 70 to 74, and 75 and older. Smoking was associated with a lower risk of joint replacement, the association directly proportional to the amount of tobacco smoked in all three age groups.

So, what might be causing this observation?

Is it that smokers don’t suffer the obesity rates seen in nonsmokers? It is true that the heaviest men (those who weigh over about 195 pounds) are more than four times likely to undergo joint replacement compared to men who weigh less than 150 pounds.

Is there something in that cigarette? There is evidence that smoking may reduce the severity of degenerative joint disease (the wear-and-tear-of-cartilage arthritis most of us will suffer to some extent as we age): Laboratory research has shown an association between nicotine and the stimulation of chondrocytes—the cells that lay down cartilage within the joint.

Alas, another blow to those of us who know what is good and not good for us: Researchers also observed that vigorous exercise increased the risk of joint replacement surgery in men aged 70 to 74.

Many of us might not be old yet, but just remember as you lace those running shoes, light up that Marlboro Light, or wash down that slice with a Big Gulp: According to the 2007 National Hospital Discharge Survey, approximately 230,000 Americans underwent hip replacement surgery that year; and 543,000 were the recipients of new knees. Osteoarthritis refractory to more conservative treatment led to most of these surgeries.

What are you going to do about it?