Abstract P108: Post-Diagnosis Body Weight Change and Cardiovascular Outcomes in Cancer Survivors

Abstract

Background: The development of cancer and its treatment often entail changes in body weight. This study aimed to investigate the association of post-diagnosis body weight change with cardiovascular disease (CVD) risk in cancer survivors. Methods: From the Korean National Health Insurance database, we identified 112,565 3-year cancer survivors who had been diagnosed with cancer at age ≥20 years from 2006 through 2013 and had normal body weight (body mass index [BMI] 18.5-22.9 kg/m2) before a cancer diagnosis. In categorical analysis, participants were classified into 4 groups according to their post-diagnosis BMI: 1) obesity (BMI ≥25 kg/m2); 2) overweight (BMI 23-24.9 kg/m2); 3) normal weight (BMI 18.5-22.9 kg/m2); and 4) underweight (BMI <18.5 kg/m2). In continuous analysis, post-diagnosis change in BMI was assessed by subtracting pre-diagnosis BMI from post-diagnosis BMI. The primary outcome was CVD event, defined as a composite of myocardial infarction, stroke, heart failure, or cardiovascular death. We examined the association of post-diagnosis BMI change with CVD risk using cause-specific Cox model. Results: Over a median follow-up of 5.5 years, 3,797 new CVD events occurred. The cumulative incidence of CVD according to post-diagnosis BMI was the highest in the obesity group, followed by underweight, overweight, and normal weight groups (Figure A). The findings remained broadly consistent after multivariable adjustment; being obese post-diagnosis was associated with a higher CVD risk than maintaining normal weight (HR 1.28, 95% CI 1.05-1.58). However, being underweight post-diagnosis was no more associated with the risk of CVD (HR 0.99, 95% CI 0.86-1.14) (Figure B). Similar findings were observed in a continuous analysis (Figure C). Conclusions: Weight gain after a cancer diagnosis was associated with a higher CVD risk, whereas the association was null for post-diagnosis weight loss. CVD prevention programs for cancer survivors should consider incorporating strategies for preventing weight gain.