Obesity fuels the upsurge in rheumatoid arthritis.

Article · April 2012with23 Reads
Source: PubMed


    OBJECTIVE: To determine whether the "obesity epidemic" could explain the recent rise in the incidence of RA. BACKGROUND: Obesity is an under-recognized risk factor for RA. In recent years both the prevalence of obesity and the incidence of RA have been rising. METHODS: An inception cohort of Olmsted County, Minnesota residents who fulfilled 1987 American College of Rheumatology criteria for RA in 1980-2007 was compared to population-based controls (matched on age, sex and calendar year). Heights, weights and smoking status were collected from medical records. Obesity was defined as body mass index (BMI) = 30 kg/m2. Conditional logistic regression was used to assess the influence of obesity on developing RA. Population attributable risk was used to estimate the incidence of RA in the absence of obesity. RESULTS: The study included 813 patients with RA and 813 controls. Both groups had extensive medical history available prior to incidence/index date (mean 32.2 years), and approximately 30% of each group were obese at incidence/index date. The history of obesity was a significant risk factor for developing RA (OR:1.24; 95 % CI: 1.01, 1.53 adjusted for smoking status). In 1985-2007 the incidence of RA rose by an increment of 9.2 per 100,000 among women. Obesity accounted for 4.8 per 100,000 (or 52%) of this increase. CONCLUSION: Obesity is associated with a modest risk for developing RA. Given the rapidly increasing prevalence of obesity, this has had a significant impact on RA incidence and accounts for much of the recent increase in incidence of RA. © 2012 by the American College of Rheumatology.