Male smokers may be less likely to need total knee or hip replacement

Men who smoke are less likely to undergo total joint replacement surgery than those who have never smoked, according to a study recently published in Arthritis and Rheumatism.

The findings also suggest men who are overweight or engaged in vigorous physical activity are more likely to need arthroplasty.

“Our study is the first to demonstrate a strong inverse correlation between smoking duration and risk of total joint replacement,” study author George Mnatzaganian, a PhD student from the University of Adelaide in Australia, stated in a press release. “The independent inverse associations of smoking with risk of total joint replacement were evident also after adjusting for major confounders and after accounting for the competing mortality risk in this elderly cohort of men.”

Mnatzaganian and his team collected clinical data for 11,388 men in the Health in Men Study. They examined the cohort for associations between smoking, body mass index (BMI) and physical activity as they relate to the risk of joint replacement surgery. Hospital morbidity data and mortality records were integrated into the examinations.

The researchers identified 857 men who had joint replacement surgery following their initial screenings. Of those who had surgery, 59% had total knee replacement and 41% had total hip replacement. These subjects were categorized into three age groups: 65 years to 69 years, 70 years to 74 years and 75 years of age or older.

Analysis of the findings showed that being overweight independently increased the risk for total joint replacement while smoking lowered it. This decrease in risk most evident after 23 years of smoking exposure. Furthermore, the authors noted, men who smoked 48 years or more were up to 51% less likely to undergo total joint replacements than those who never smoked.

The authors also added that vigorous exercise increased the risk of joint replacement in men 70 years to 74 years of age.

Reference:
Mnatzaganian G, Ryan P, Norman PE et al. Smoking, body weight, physical exercise and risk of lower limb total joint replacement in a population-based cohort of men. Arthritis Rheum. 2011. doi: 10.1002/art.30400.

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