Abstract P520: Associations of Dietary Patterns and Risk of Sudden Cardiac Death in the Reasons for Geographic and Racial Differences in Stroke Study Differ by History of Coronary Heart Disease

Abstract

Introduction: Previous investigations of the association of a healthy dietary pattern, the Mediterranean (Med) diet, and risk of sudden cardiac death (SCD) are limited and generally have not examined possible differences in those with and without a history of coronary heart disease (CHD). Studies of the associations of a posteriori -derived dietary patterns and risk of SCD are lacking. We conducted analyses of the associations of these dietary patterns with risk of SCD in the REasons for Geographic and Racial Differences in Stroke (REGARDS) study. Hypothesis: We hypothesized that the Med diet score and adherence to the plant-based dietary pattern would be inversely associated with risk of SCD, adherence to the convenience and Southern dietary patterns would be positively associated with risk of SCD, and that these associations would differ by history of CHD. Methods: REGARDS enrolled 30,239 white and black adults aged ≥45 years from 2003-2007. Participants completed a food frequency questionnaire at baseline, from which 5 dietary patterns were derived through factor analysis: convenience, plant-based, sweets, Southern, and alcohol and salads. Med diet scores were calculated and categorized into 3 groups. SCD events were expert adjudicated. Cox proportional hazards regression was used to model the associations of the dietary patterns and score with SCD events, adjusting for sociodemographics, lifestyle factors, energy intake, anthropometrics, medical conditions, and medications, and stratifying by history of CHD. Results: After excluding participants with missing diet and covariate data and those lost to follow-up, 21,066 participants were included in the analysis. Mean (SD) age was 64.9 (9.3) years, 56.0% were women, 33.2% were black, and 385 (1.8%) experienced SCD during a mean (SD) follow-up of 9.2 (3.4) years. In those without a history of CHD, Med diet score was significantly and inversely associated with risk of SCD (hazard ratio [HR] for group 3 vs. group 1 [referent]: 0.55; 95% confidence interval [CI]: 0.35-0.89; p trend = 0.02), but none of the a posteriori -derived dietary patterns were associated with risk of SCD. However, in those with a history of CHD, Med diet score was not associated with risk of SCD, but the convenience dietary pattern was significantly and positively associated with risk of SCD (HR for quartile 4 vs. quartile 1 [referent]: 1.74; 95% CI: 1.08-2.78; p trend = 0.04), and the sweets dietary pattern was significantly and inversely associated with risk of SCD (HR for quartile 4 vs. quartile 1: 0.56; 95% CI: 0.33-0.94; p trend = 0.01). Conclusions: The associations of dietary patterns with risk of SCD in REGARDS participants differed by history of CHD.