Abstract 09: A Community-Based Exercise Intervention Transitions Metabolically Abnormal Obese Adults to a Metabolically Healthy Obese Phenotype

Abstract

Introduction: It has been estimated that 32% of obese adults in the US are metabolically healthy. This subset of individuals, referred to as metabolically healthy but obese (MHO), appear to be more resistant to the adverse cardiometabolic consequences faced by their metabolically abnormal obese (MAO) counterparts. Cross-sectional observations indicate that increased physical activity and higher fitness contribute to the protective metabolic characteristics in this subset of obese individuals. However, to date no study has investigated whether a community-based exercise intervention designed to increase exercise volume and fitness can transition MAO adults to a MHO phenotype. Identifying the therapeutic dose of exercise required to convert a MAO person to metabolically healthy would yield important clinical information for the primary prevention of cardiovascular disease. Hypothesis: We assessed the following hypotheses: (1) community-based exercise training would transition MAO adults to metabolically healthy, and (2) the odds of successful transition to a metabolically healthy phenotype would be larger for obese individuals who [[Unable to Display Character: –]] (a) performed the highest volume of exercise, and (b) experienced the greatest increase in fitness. Methods: Three-hundred thirty-two healthy adults (190 women, 142 men; aged 28-88 years) engaged in a supervised 14-week community-based exercise program designed to favorably modify cardiovascular disease risk factors. Components of the metabolic syndrome (National Cholesterol Education Program ATP III criteria) were measured before and after the exercise program. Obese (BMI ≥ 30 kg·m 2 ) adults who met 2-4 criteria for metabolic syndrome were classified as metabolically abnormal. Metabolically healthy was defined if obese adults met 0 to 1 criteria for metabolic syndrome. Results: Baseline point prevalence of MAO was 20.5% (N = 68). There was a significant reduction (p<0.05) in point prevalence of MAO to 12.3% by post program as 27/68 individuals (40%) transitioned to MHO. Compared to the lowest quartiles of relative energy expenditure and change in fitness, participants in the highest quartiles were 21.8 (95% CI 4.4[[Unable to Display Character: –]]108.0; p<0.05) and 8.2 (95% CI 3.1[[Unable to Display Character: –]]21.6; p<0.05) times more likely to transition from MAO to MHO, respectively. Conclusions: These findings indicate that supervised community exercise can transition MAO adults to a MHO phenotype. MAO adults who engaged in higher volumes of exercise and those who demonstrated greater improvements in fitness were significantly more likely to become metabolically healthy. Importantly, the unfavourable metabolic characteristics of obesity are not irreversible. Community exercise should be considered an effective model for the primary prevention of cardiovascular disease in MAO adults.