Low-Carbohydrate Diets and Risk of Incident Atrial Fibrillation: A Prospective Cohort Study

Background-The influences of low-carbohydrate diets in cardiovascular disease are controversial. Few studies have examined the relationship of carbohydrate intake and risk of incident atrial fibrillation (AF). We aimed to evaluate the association between carbohydrate intake and the risk of incident AF in the ARIC (Atherosclerosis Risk in Communities) Study. Methods and Results-We included 13 385 participants (age, 54.2 +/- 5.8 years; 45.1% men and 74.7% white) who completed a dietary questionnaire at baseline (1987-1989) in the ARIC Study. The primary outcome was incident AF, which was identified by ECG performed during study examinations, hospital discharge codes, and death certificates. We used multivariable Cox hazard regression models to assess the association between carbohydrate intake and incident AF. We further explored the effects of specific food source (animal versus plant based) used to replace carbohydrate intake in the low-carbohydrate intake setting. During a median follow-up of 22.4 years, 1808 cases (13.5%) of AF occurred. The hazard ratio for incident AF associated with a 1-SD (9.4%) increase in carbohydrate intake as a percentage of energy intake was 0.82 (95% CI, 0.72-0.94), after adjustment for traditional AF risk factors and other diets factors. Results were similar when individuals were categorized by carbohydrate intake quartiles (hazard ratio, 0.64; 95% CI, 0.49-0.84; comparing extreme quartiles). No association was found between the type of protein or fat used to replace the carbohydrate and risk of incident AF. Conclusions-Low-carbohydrate diets were associated with increased risk of incident AF, regardless of the type of protein or fat used to replace the carbohydrate.