Abstract 3172: Association between Weight Change and Incidence of Congestive Heart Failure in the Framingham Heart Offspring Study - Death as a Competing Event
Introduction: Weight loss in patients with congestive heart failure (CHF) has been linked to impaired survival. However, the effect of weight change on cardiovascular outcome in the general population is less clear, as previous studies have not adjusted for death as a competing event.
Methods: We investigated the influence of weight change on CHF incidence and death in 2908 healthy participants of the Framingham Heart Offspring Study (age: all >30 yrs, mean 49 ± 7.6y; 51% women; cases with cancer excluded). Weight change was defined as percent change in body mass index between 2 exams, adjusted to percent change over 4 years. Primary endpoint was ‘CHF or death’; secondary endpoint was ‘incident CHF’ with death censored. We used Cox Proportional Hazards models with baseline variables to estimate adjusted hazard ratios (HR) with 95% confidence intervals (CI). All results were adjusted for risk factors of CHF, including BMI, diabetes, cholesterol, myocardial infarction, smoking, and alcohol consumption. In a sensitivity analysis, we used the extended Cox model with time-dependent covariates.
Results: During follow-up (mean 14 ±3.1y) there were 261 endpoints of ‘CHF or death’, and 80 of ‘incident CHF’. Compared to constant weight, weight loss ≥5% had a HR of 1.59 (95% CI: 1.06–2.39, p<0.03) for ‘CHF or death’ and a HR of 2.63 (95% CI: 1.39 – 4.97, p<0.003) for ‘CHF’. Weight gain ≥5% had a HR of 1.06 (95% CI: 0.67–1.68, p=0.81) for ‘CHF or death’, and had a HR of 0.89 (95% CI: 0.36–2.19, p=0.80) for ‘CHF’. For weight loss ≥5%, the model with time-varying variables estimated a HR of 1.74 (95% CI: 1.26–2.41, p<0.002) for ‘CHF or death’ and of 1.17 (95% CI: 0.62–2.18, p=0.63) for ‘CHF’ when compared to constant weight. For weight gain ≥5%, the HR was 0.91 (95% CI: 0.64–1.29, p=0.58) for ‘CHF or death’ and 0.59 (95% CI: 0.30–1.15, p=0.12) for ‘CHF’.
Conclusion: Our analyses showed an association between weight change and the incidence of congestive heart failure and death in a general population independent of established risk factors and controlled for body weight. Weight loss ≥5% is detrimental, but weight gain appears to have a neutral impact. Further research is needed to investigate the time-dependent causal effect of different levels of weight change on CHF and survival.