#4412 URINARY SODIUM-TO-POTASSIUM RATIO DOES NOT ACCURATELY REFLECT DIETARY SODIUM-TO-POTASSIUM RATIO

Abstract Background and Aims Low sodium intake is associated with a lower blood pressure less proteinuria, which are important therapeutic targets in chronic kidney disease. In contrast, low potassium has been higher incidence of disease cardiovascular events. Counselling patients regarding their requires accurate estimation intake, but 24-hour urinary excretion can deviate substantially from actual intake. Urinary sodium-to-potassium (Na/K) ratio promising alternative as it affected by incomplete urine collections additionally captures both the effect potassium. Our study aimed to assess whether Na/K reflects dietary more accurately than separate measurement or urine. Method We performed post-hoc analysis on data long-term balance studies Mars105 Mars520. Ten healthy participants consumed diet known content collected samples for 105 205 days. calculated log fold difference between sodium, ratio. A mixed-effects model random intercept per subject was used compare these estimates accuracy. Subsequently, we subgroup salt level (i.e. 6, 9 12 grams day) assessed increasing number collections. Results Overall, underestimated median -0.21 (IQR -0.47 0.09). Estimation using significantly compared (Figure 1A). Only during 6 day, did not perform worse measurements. Although measurements three seven improved accuracy ratio, remained inferior assessment 1B). Conclusion The controlled setting volunteers.