Abstract 18402: Impact of Obesity on Outcomes After Percutaneous Coronary Intervention in Japanese Population: Obesity Paradox with High Waist Circumference but Not High BMI

Abstract

Introduction: Although the counterintuitive association between obesity and mortality has been termed the obesity paradox, the evaluation of obesity was inconsistent, and evidence for an obesity paradox among past studies has been also less consistent. Hypothesis: This inconsistency may be due, in part, to a discrepancy between central obesity, estimated by waist circumference (WC), and body mass index (BMI) as patterns of adiposity. Methods: To elucidate the impact of obesity, 2817 subjects with both WC and BMI data were enrolled from the data of Kumamoto Intervention Conference Study (KICS), a multicenter registry, enrolling consecutive patients undergoing PCI in 15 centers from August 2008 to March 2011 in Japan. Subjects were stratified according to patterns of adiposity (WC or BMI), utilizing NCEP-ATPIII criteria and WHO classification. Results: Subjects’ mean age was 69.8 years, and 28% were female. There were 68 deaths during 12-month follow up. Although obesity defined by WC (ObWC) was associated with lower mortality compared with non-obesity (no-ObWC, p=0.013), no difference was shown between obesity, defined by BMI (ObBMI), and non-obesity (no-ObBMI) (p=0.201). When dividing into 4 categories based on high/low of WC and BMI, subjects with high WC and high BMI had the lowest mortality (1.6%) compared to other 3 categories (high WC low BMI; 1.7%, low WC high BMI; 2.4%, or low WC and low BMI; 3.1%). Kaplan-Meier analysis for all cause mortality showed a significant difference between ObWC and no-ObWC (Log Rank p=0.010), but comparable in BMI (ObOMI vs no-ObBMI, p=0.295). This discrepancy was also observed in the analysis for cardiac death (Figure). In multivariate analysis, in addition to age and CKD, ObWC was an independent predictor for the low mortality (OR; 0.582, 95% CI; 0.342-0.991, p=0.046). Conclusions: In Japanese patients with known CAD who undergo PCI, central obesity but not BMI is associated with the paradoxical protective effect of obesity.