Overweight Exercise Tied to Increased Joint Replacement Risk
Link seen in men but decreased risk of total joint replacement in men who smoke
TUESDAY, July 12 (HealthDay News) -- Men who are overweight and engage in vigorous exercise have an increased risk of undergoing total joint replacement (TJR), according to a study published online July 11 in Arthritis & Rheumatism.
George Mnatzaganian, from the University of Adelaide in Australia, and colleagues investigated whether smoking, body weight, and physical activity are associated with an increased risk of TJR. Clinical records from 11,388 men who were part of the Health in Men Study were analyzed, and data were integrated with hospital morbidity and mortality records. The risk of TJR were modeled on baseline weight, height, comorbidity, injury, socioeconomic status, years of smoking, and exercise in three different age groups using Cox proportional hazards regressions and competing risk regressions (CRR).
The investigators found that being overweight increased, and smoking decreased, the risk of TJR. Both the Cox and CRR models demonstrated a decreased risk for smokers, which became evident after 23 years of exposure. Compared to never-smokers, men who smoked for 48 or more years were 42 to 51 percent less likely to undergo TJR. The log hazard ratios (HR) across both smoking and weight quantiles were significant. Vigorous exercise showed an increased risk for TJR, but statistical significance for this association was reached only in the 70- to 74-year-old age group (adjusted HR, 1.64). The associations persisted after adjusting for Deyo-Charlson Index and Elixhauser's comorbidities.
"This population-based cohort study has shown an increased risk for TJR with body weight and vigorous exercise, and an inverse association with smoking," the authors write.