269926 Expanding the fit-fat debate: Does cardiovascular fitness moderate the effect of high BMI on arthritis?

Wednesday, October 31, 2012

Catherine Marinac, BA , Cancer Prevention and Control Program, University of California San Diego UCSD Moores Cancer Center, La Jolla, CA
Jennifer Emond, MS , Cancer Prevention and Control Program, University of California San Diego (UCSD) Moores Cancer Center, La Jolla, CA
Ruth Patterson, Ph D , Moores Cancer Center, Cancer Prevention and Control Program, University of California San Diego (UCSD), La Jolla, CA
Introduction: Obesity is a risk factor for common types of arthritis, an inflammatory disease affecting over 46 million US adults. Fitness may prevent arthritis by lowering chronic inflammation, as assessed with circulating biomarkers such as C-reactive protein (CRP). This analysis examined how fitness influences the relationship between BMI and arthritis.

Methods: Analyses included 1,368 adults (30-85 years old) from the NHANES Survey (1999-2000) who completed a sub-maximal cardiovascular fitness test. Participants were grouped into fitness categories (low, moderate, high) using age-specific cut-points. Multivariate logistic regression fit arthritis status on age, gender, race, education, BMI, fitness level, and a fitness x BMI interaction. All analyses accounted for appropriate survey weights.

Results: In comparison with low fitness, high fitness was associated with lower prevalence of arthritis (OR: .55; 95% CI: .30-.92) and lower CRP concentrations (p =.0012). In comparison with normal weight, obesity was positively associated with higher prevalence of arthritis (OR: 1.42; 95% CI: 1.20-1.68) and CRP concentrations (p<.0001). However, there was a significant interaction of fitness categories with BMI (p<0.05). In comparison with low fitness, high fitness was only significantly associated with lower prevalence of arthritis among adults with BMI< 25 (OR .92; 95% CI: .07-.55). High fitness did not appear to be protective for adults in overweight or obese categories.

Conclusion: Although limited by the cross-sectional nature of this analysis, these results suggest that weight-loss may be more important for arthritis prevention among overweight and obese adults. Longitudinal studies are needed to confirm these findings.

Learning Areas:
Chronic disease management and prevention

Learning Objectives:
1.)Compare how cardiovascular fitness and BMI levels independently relate to arthritis. 2.)Compare how cardiovascular fitness and BMI levels independently relate to inflammation. 3.)Investigate whether the relationship between BMI and both inflammation and arthritis is modified by cardiovascular fitness.

Keywords: Arthritis, Physical Activity

Presenting author's disclosure statement:

Qualified on the content I am responsible for because: I am a doctoral student in public health at University of California San Diego and San Diego State University with 5 years of research experience in biochemistry and clinical metabolism at the following institutions: Mayo Clinic, Lawrence University, and NIH/NIDDK.
Any relevant financial relationships? No

I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.