Abstract 15707: Dietary Potassium and Sodium Intake and Cardiovascular Fitness in United States Community Dwelling Young Adults

Abstract

Introduction: Low cardiovascular fitness strongly predicts cardiovascular disease and all-cause mortality in adults. Higher sodium (Na) and lower potassium (K) intakes have shown to be associated with adverse cardiovascular events. However, the association of K and Na intake with cardiovascular fitness is unknown in young adults. Methods: We included data on participants aged 20 to 49 years from three cycles (1999-2004) of the National Health and Nutrition Examination Survey. Estimated VO2max was measured using submaximal exercise test. 24-hour dietary interview format was used to estimate Na and K intake. The main exposure of interest was Na and K intake per 1000mg/day, and a nine-category variable for joint Na and K intake was generated by dividing Na and K intake into tertiles (low, moderate, high). The main outcome measure was eVO2max scaled to standard deviation (1-SD). The cross-sectional association between Na and K intake and eVO2max was assessed using survey design-based multivariable linear regression adjusted for clinically and biologically plausible confounders. Results: There were 3222 participants, with mean age 33.9 years; 48% were female and 70.6% identified as White. Only 27 (0.8%) participants met the dietary recommendation goal for Na (<2g) and K (>3.5g) intake per the World Health Organization. K intake per 1000mg was positively associated with a (1-SD) increase in eVO2max (β estimate = 0.04, P value = 0.01) in a fully adjusted model. Na intake per 1000mg was positively associated with (1-SD) increase in eVO2max (β estimate = 0.004, P value = 0.80) without reaching statistical significance in a fully adjusted model. The association of K intake and eVO2max was modified by Na intake ( P value = 0.01). The joint category with moderate Na intake and high K intake was positively associated with eVO2max (β estimate = 0.21, P value = 0.009) compared to the joint category with low Na and K intake in a fully adjusted model. Conclusion: These findings suggest that higher potassium intake is associated with higher cardiovascular fitness independent of blood pressure, especially in conjunction with lower sodium intake. Higher potassium intake may have a role in improving cardiovascular fitness in young adults and could prevent future cardiovascular events.