Urinary sodium to potassium ratio: A simple and useful indicator of diet quality in population-based studies
Abstract Background Urinary sodium (Na) and potassium (K) are related to dietary intakes of Na and K, and well-known risk factors of hypertension and cardiovascular events. This study aimed to evaluate the associations between urinary Na/K ratio and different dietary patterns. Methods we recruited 1864 adult men and women (aged 18-93 years), participated in the sixth examination of Tehran Lipid and Glucose Study. Fasting spot urine samples were collected and concentrations of Na and K were determined. The principle component analysis (PCA) was conducted to drive major dietary patterns among population. Mediterranean dietary pattern score, as well as DASH score, were calculated. Linear regression models adjusted for potential confounding variables were used to assess associations between dietary patterns scores and urinary Na/K ratio. Results Mean age of participants was 43.7±13.9 years, and 47% were men. Mean urinary Na and K concentrations were 139±41.0 and 57.9±18.6 mmol/L, respectively. Mean urinary Na/K was 2.40±0.07. A significant positive association was found between Western dietary pattern and urinary Na/K ratio (β=0.06; 95% CI= 0.01, 0.16). Traditional dietary pattern derived from usual dietary intakes of Iranian adults, as well as Mediterranean and DASH dietary pattern scores were inversely associated to urinary Na/K ratio (β= –0.14; 95% CI= –0.24, –0.11, β=–0.07; 95% CI= –0.09, –0.01, β=–0.12; 95% CI= –0.05, –0.02, respectively). Conclusions Urinary Na/K ratio may suggest as a simple, inexpensive and helpful method to monitor and improve diet quality in population-based studies.