Presentation Abstract

Session: 12-Nutrition
Wednesday, Mar 03, 2010, 5:00 PM - 7:00 PM
Presentation: P165 - Habitual Dietary Sodium Intake Is Inversely Associated with Coronary Flow Reserve Detected by Positron Emission Tomography
Location: Grand Ballroom A
Pres. Time: Wednesday, Mar 03, 2010, 5:00 PM - 7:00 PM
Category: +EPI - Nutrition
Keywords: Cardiovascular disease; Sodium; Diet
Author(s): Silvia C Eufinger, Emory Univ, Atlanta, GA; John Votaw, Tracy Faber, Thomas R Ziegler, Emory Univ Sch of Med, Atlanta, GA; Jack Goldberg, Vietnam Era Twin Registry, Seattle, WA; J Douglas Bremner, Viola Vaccarino, Emory Univ Sch of Med, Atlanta, GA
Abstract: Introduction: Evidence links habitual dietary salt intake to hypertension and cardiovascular disease, but investigation of its influence on cardiovascular function is limited. We sought to examine the relationship between habitual dietary sodium and coronary flow reserve (CFR), a measure of overall coronary vasodilator capacity and microvascular function.
Hypothesis: Higher habitual sodium consumption is associated with lower CFR.
Methods: The Willett food-frequency questionnaire was administered to 288 male middle-aged predominantly healthy twins, including 135 monozygotic and dizygotic twin pairs and 18 unpaired twins, who were recruited from the Vietnam Era Twin Registry. Reported food intake was used to derive habitual daily dietary sodium intake for the previous 12 months. CFR was measured by positron emission tomography [N13] ammonia, with quantitation of myocardial blood flow at rest and after adenosine stress. Mixed-effect regression analysis was used to examine between- and within-twin pair differences.
Results: The twins’ mean age was 54 years (SD = 3), and 91% (263 out of 288) were white. An increment in dietary sodium of 1000 mg/d was associated with a 9% lower CFR (95% CI: -16.0, -2.0) after adjustment for energy intake, other nutritional factors, demographic characteristics, and CVD risk factors (P = 0.02). Across quintiles of sodium consumption, CFR was inversely associated with dietary sodium (P for trend = 0.03) with the top quintile (sodium >1458 mg/d) having a 15.6% lower CFR than the bottom quintile (sodium <728 mg/d). This association persisted within twin pairs: a 1000 mg/d within-pair difference in dietary sodium was associated with an 8% lower CFR in the twin with the higher dietary sodium than in the co-twin with the lower dietary sodium (P = 0.05). These associations did not differ by zygosity.
Conclusions: Habitual dietary sodium is inversely associated with CFR, a measure of coronary microvascular function, independent of CVD risk factors and shared familiar and genetic factors. Our study provides a novel mechanism for the adverse effects of dietary salt on the cardiovascular system and support the importance of reducing salt intake to promote cardiovascular health.
Disclosures:  S.C. Eufinger: None. J. Votaw: None. T. Faber: None. T.R. Ziegler: None. J. Goldberg: None. J.D. Bremner: None. V. Vaccarino: None.