Abstract P016: Dietary Carbohydrate Intake and QT Interval: The Third National Health and Nutritional Examination Survey (NHANES III)
Prolonged QT interval is associated with increased cardiovascular mortality and sudden death. Data on the relationship between dietary carbohydrate intake and QT interval are scarce. We cross-sectionally examined the association between dietary carbohydrate intakes and QT interval in a nationally representative sample of U.S. adults, with the consideration of three types of carbohydrate replacements. Our study included 7,867 participants aged 20 years and older in NHANES III (1988-1994). QT interval was measured using a standard 12-lead electrocardiogram. Dietary data were collected using single 24-hour dietary recall. Three low-carbohydrate-diet (LCD) scores were generated: overall LCD score was calculated based on total carbohydrate, fat, and protein, an animal-based LCD score was calculated using intakes of saturated fat and animal protein, and a prudent LCD score was calculated using intakes of unsaturated fat and vegetable protein. Restricted quadratic spline models with knots at the 5th, 50th, and 95th percentile adjusted for age, sex, race, physical activity level, total energy intake, current smoking status, alcohol intake, history of cardiovascular disease, and RR-interval were used to calculate adjusted QT intervals and test for trends. The mean (SE) age of this study sample was 56.6 (0.4) years and the mean of body mass index was 27.3 (0.1) kg/m2. Adjusted QT intervals ranged from 409.8 ms in the lowest stratum to 407.3 ms in the highest stratum of the overall LCD score, from 409.8 ms in the lowest stratum to 406.8 ms in the highest stratum of the animal LCD score, and from 411.2 ms in the lowest stratum to 407.2 ms in the highest stratum of the prudent LCD score. Significant linear trends were observed for all three LCD scores (P value for trend: 0.01 for the overall LCD score, 0.007 for the animal-based LCD score, and 0.02 for the prudent LCD score). In conclusion, a diet higher in carbohydrates and lower in protein and fat was associated with a longer QT interval, regardless of protein and fat sources.
- © 2013 by American Heart Association, Inc.