Estimated 24 Hour Urinary Sodium and Potassium Excretion in a Population of Moroccan Adults

Background: Excessive sodium (Na) intake and low potassium (K) intake are associated with adverse cardiovascular health outcomes. Morocco lacks data on actual Na and K intake in adults. The aim of this study was to estimate the mean intake of Na and K in a Moroccan population of adults using the 24-h urinary excretion and to examine their association with blood pressure (BP). Methods: A total of 371 adults, who participated in the urinary validation sub-study of the STEP-wise Survey-Morocco-2017-2018, have complete data on demographic, anthropometric and blood pressure and have provided a valid 24-h urine collection according to the standard protocol of the World Health Organization (WHO). Results: The mean 24-h urinary sodium excretion was 2794 mg (SD, 1394) and the median was 2550 mg (IQR, 1780-3726). The mean 24-h urinary potassium excretion was 1898 mg (SD, 1044) and the median was 1640 mg (IQR, 1170-2410). Sodium excretion was between 3000 and 5000 mg/day in 31% of participants, < 3000 mg/day in 64%, and > 5000 mg/day in only 5%. No significant association of urinary sodium or potassium with blood pressure was found. Conclusion: Sodium intake in the studied population of Moroccan adults was higher than WHO recommendation and was comparable to levels reported in countries from Eastern Mediterranean Region. The vast majority of participants had a sodium intake < 5000 mg/day, with only 5% were above this level. Potassium intake was in the range of 1000 to 3000 mg/day. Within these ranges, there was no association between sodium or potassium intake and blood pressure. This information is crucial to help implement the national strategy to reduce sodium intake as a cost-effective intervention to prevent chronic disease in Morocco.

Urinary Potassium Excretion, Fibroblast Growth Factor 23, and Incident Hypertension in the General Population-Based PREVEND Cohort

High plasma fibroblast growth factor 23 (FGF23) and low potassium intake have each been associated with incident hypertension. We recently demonstrated that potassium supplementation reduces FGF23 levels in pre-hypertensive individuals. The aim of the current study was to address whether 24-h urinary potassium excretion, reflecting dietary potassium intake, is associated with FGF23, and whether FGF23 mediates the association between urinary potassium excretion and incident hypertension in the general population. At baseline, 4194 community-dwelling individuals without hypertension were included. Mean urinary potassium excretion was 76 (23) mmol/24 h in men, and 64 (20) mmol/24 h in women. Plasma C-terminal FGF23 was 64.5 (54.2–77.8) RU/mL in men, and 70.3 (56.5–89.5) RU/mL in women. Urinary potassium excretion was inversely associated with FGF23, independent of age, sex, urinary sodium excretion, bone and mineral parameters, inflammation, and iron status (St. β −0.02, p < 0.05). The lowest sex-specific urinary potassium excretion tertile (HR 1.18 (95% CI 1.01–1.37)), and the highest sex-specific tertile of FGF23 (HR 1.17 (95% CI 1.01–1.37)) were each associated with incident hypertension, compared with the reference tertile. FGF23 did not mediate the association between urinary potassium excretion and incident hypertension. Increasing potassium intake, and reducing plasma FGF23 could be independent targets to reduce the risk of hypertension in the general population.

Association of Urinary Potassium Excretion with Blood Pressure Variability and Cardiovascular Outcomes in Patients with Pre-Dialysis Chronic Kidney Disease

Dietary potassium intake is a dilemma in patients with chronic kidney disease (CKD). We investigated the association of urine potassium excretion, a surrogate for dietary potassium intake, with blood pressure variability (BPV) and cardiovascular (CV) outcomes in patients with pre-dialysis CKD. A total of 1860 participants from a cohort of pre-dialysis CKD (KNOW-CKD) patients were divided into the quartiles by spot urine potassium-to-creatinine ratio. The first quartile (26.423 ± 5.731 mmol/gCr) was defined as low urine potassium excretion. Multivariate linear regression analyses revealed an independent association of low urine potassium excretion with high BPV (adjusted β coefficient 1.163, 95% confidence interval 0.424 to 1.901). Cox regression analyses demonstrated that, compared to high urine potassium excretion, low urine potassium excretion is associated with increased risk of CV events (adjusted hazard ratio 2.502, 95% confidence interval 1.162 to 5.387) but not with all-cause mortality. In conclusion, low urine potassium excretion is associated with high BPV and increased risk of CV events in patients with pre-dialysis CKD. The restriction of dietary potassium intake should be individualized in patients with pre-dialysis CKD.

Nalfurafine, a G-Protein–Biased KOR (Kappa Opioid Receptor) Agonist, Enhances the Diuretic Response and Limits Electrolyte Losses to Standard-of-Care Diuretics

Nalfurafine is a G-protein–biased KOR (kappa opioid receptor) agonist that produces analgesia and lacks CNS adverse effects. Here, we examined the cardiovascular and renal responses to intravenous and oral nalfurafine alone and in combination with furosemide, hydrochlorothiazide, or amiloride. We hypothesized that nalfurafine, given its distinct mechanism of vasopressin inhibition, would increase urine output to these diuretics and limit electrolyte loss. Following catheterization, conscious Sprague-Dawley rats received an isotonic saline infusion and were then administered an intravenous bolus of nalfurafine, a diuretic, or a combination. Mean arterial pressure, heart rate, and urine output were recorded for 90 minutes. In another study, rats were placed in metabolic cages and administered drug in an oral volume load. Hourly urine samples were then collected for 5 hours. Intravenous and oral nalfurafine produced a marked diuresis, antinatriuresis, antikaliuresis, and a decrease in mean arterial pressure. Compared with diuretic treatment alone, intravenous coadministration with nalfurafine significantly increased urine output to furosemide and hydrochlorothiazide and decreased sodium and potassium excretion. Notably, mean arterial pressure was reduced with nalfurafine/diuretic combination therapy compared to diuretics alone. Similarly, oral coadministration of nalfurafine significantly increased urine output to hydrochlorothiazide and decreased sodium and potassium excretion, whereas combination with furosemide only limited the amount of sodium excreted. Further, both intravenous and oral coadministration of nalfurafine enhanced the diuresis to amiloride and decreased sodium excretion. Together, these findings demonstrate that nalfurafine enhances the diuresis to standard-of-care diuretics without causing an excessive loss of electrolytes, offering a new approach to treat several cardiovascular conditions.

High Adherence to Mediterranean Diet Is Not Associated with an Improved Sodium and Potassium Intake

Prevention and control of hypertension and cerebro-cardiovascular diseases are associated with adequate sodium and potassium intake and adherence to a Mediterranean dietary pattern. The aim of this study was to assess the association between adherence to a Mediterranean diet (MD) and the excretion of sodium and potassium as surrogate measures of intake. This is a cross-sectional analysis as part of a larger study (the iMC SALT randomized controlled trial) among workers of a public university. A food frequency questionnaire was used to assess the adherence to MD, using the alternative Mediterranean diet (aMED) score; sodium and potassium excretions were estimated by 24-h urine collections. Sociodemographic and other lifestyle characteristics were also obtained. The associations between the adherence to MD and Na and K excretion were calculated by logistic regression, adjusting for confounding variables. From the 109 selected participants, seven were excluded considering urine screening and completeness criteria, leaving a final sample of 102 subjects (48% male, average age 47 years). Mean sodium and potassium excretion were 3216 mg/day and 2646 mg/day, respectively. Sodium and potassium excretion were significantly higher in men, but no differences were found according to different levels of MD adherence. In logistic regression analysis, sodium, potassium, and sodium-to-potassium ratio urinary excretion tertiles were not associated with MD adherence (low/moderate versus high), even after adjustment for confounding variables. A high adherence to MD was thus not associated with a different level of sodium and potassium intake.

Accuracy of equations for predicting 24-h urinary potassium excretion from spot urine samples in Chinese children

Accurate assessments of potassium intake in children are important for the early prevention of CVD. Currently, there is no simple approach for accurate estimation of potassium intake in children. We aim to evaluate the accuracy of 24-h urinary potassium excretion (24UKV) estimation in children using three common equations: the Kawasaki, Tanaka and Mage formulas, in a hospital-based setting. A total of 151 participants aged 5–18 years were initially enrolled, and spot urine samples were collected in the whole 24-h duration to measure the concentrations of potassium and creatinine. We calculated the mean difference, absolute and relative difference and misclassification rate between measured 24UKV and the predicted ones using Kawasaki, Tanaka and Mage formulas in 129 participants. The mean measured 24UKV was 1193·3 mg/d in our study. Mean differences between estimated and measured 24UKV were 1215·6, −14·9 and 230·3 mg/d by the Kawasaki, Tanaka and Mage formulas, respectively. All estimated 24UKV were significantly different from the measured values in all the time point (all P < 0·05), except for the predicted values from Tanaka formula using morning, afternoon and evening spot urine. The proportions with relative differences over 40 % were 87·2%, 32·5% and 47·3 % for Kawasaki, Tanaka and Mage formulas, respectively. Misclassification rates were 91·5 % for Kawasaki, 44·4 % for Tanaka and 58·9 % for Mage formula at the individual level. Our findings showed that misclassification could occur on the individual level when using Kawasaki, Tanaka and Mage formulas to estimate 24UKV from spot urine in the child population.

Sodium and Potassium Excretion of Schoolchildren and Relationship with Their Family Excretion in China

This cross-sectional study aimed to assess 24-h urinary sodium and potassium excretion in children and the relationships with their family excretion. Using the baseline data of a randomized trial conducted in three cities of China in 2018, a total of 590 children (mean age 8.6 ± 0.4 years) and 1180 adults (mean age 45.8 ± 12.9 years) from 592 families had one or two complete 24-h urine collections. The average sodium, potassium excretion and sodium-to-potassium molar ratio of children were 2180.9 ± 787.1 mg/d (equivalent to 5.5 ± 2.0 g/d of salt), 955.6 ± 310.1 mg/d and 4.2 ± 1.7 respectively, with 77.1% of the participants exceeding the sodium recommendation and 100% below the proposed potassium intake. In mixed models adjusting for confounders, every 1 mg/d increase in sodium excretion of adult family members was associated with a 0.11 mg/d (95% CI: 0.06 to 0.16, p < 0.0001) increase in sodium excretion of children. The family-child regression coefficient corresponds to 0.20 mg/d (95% CI: 0.15 to 0.26, p < 0.0001) per 1 mg/d in potassium and to 0.36 (95% CI: 0.26 to 0.45, p < 0.0001) in sodium-to-potassium molar ratio. Children in China are consuming too much sodium and significantly inadequate potassium. The sodium, potassium excretion and sodium-to-potassium ratio of children are associated with their family excretions in small to moderate extent. Efforts are warranted to support salt reduction and potassium enhancement in children through comprehensive strategies engaging with families, schools and food environments.

24-h Potassium Excretion Is Associated with Components of the Metabolic Syndrome: Results from a National Survey Based on Urine Collection in Adults

A balanced diet and weight loss are the first lines of treatment for the prevention of metabolic syndrome (MS). Dietary strategies may include changing the composition of macronutrients, adopting a particular dietary pattern as a Mediterranean diet. However, the role of micronutrients, particularly potassium, in the propensity for or treatment of the syndrome is unclear. The study aimed to examine the relationship between the presence of the MS and its risk factors and the 24-h potassium excretion as the most valid proxy for dietary intake. The analyses were performed as part of the national survey estimating sodium and other electrolytes excretion conducted between 2014–2016 in Israel. The survey included urine collection, anthropometric and blood pressure measurements, and a comprehensive medical questionnaire that included details on the intake of medications that may affect electrolyte secretion. A model was constructed to evaluate the probability for the MS. MS score and its probability were examined in relation to potassium excretion at different levels and in stratification to sex. A total of 581 participants were included in the analysis. The mean potassium excretion was 2818 ± 1417 mg. The prevalence of the MS was 18.5% among participants with above-average potassium excretion and about 10.4% among participants with lower-than-average excretion (p = 0.007). A dose–response relationship was observed between MS score and potassium: the higher the score, the lower was the excretion of potassium. Potassium excretion, rather than sodium excretion, correlated with all components of the MS and even predicted MS independently from other variables. This is the first study based on a national survey showing that potassium consumption, as represented by daily excretion in urine, is inversely related to the presence of MS components after adjustment for several leading variables and careful exclusion of participants taking drugs which may interfere in potassium excretion.