It is strongly recommended to not conduct, fund, or publish research studies that use spot urine samples with estimating equations to assess individuals' sodium (salt) intake in association with health outcomes: a policy statement of the World Hypertension League, International Society of Hypertension and Resolve to Save Lives

Practical use and target value of urine sodium-to-potassium ratio in assessment of hypertension risk for Japanese: Consensus Statement by the Japanese Society of Hypertension Working Group on Urine Sodium-to-Potassium Ratio

Epidemiological studies have demonstrated that the urine sodium-to-potassium (Na/K) ratio is more positively associated with high blood pressure and cardiovascular disease risk than either urine sodium or potassium excretion alone. In this consensus statement, we recommend using the average Na/K ratio of casual urines randomly taken in various times on at least four days a week for a reliable individual estimate because of high day-to-day and intraday variability of casual urine Na/K ratio within individuals. Although a continuous positive association exists between the Na/K ratio and high blood pressure or cardiovascular disease risk, for clinical and public health decision making for Japanese, we recommend using an average urine Na/K ratio of 2 as an optimal target value because this aligns with recommendations for both sodium and potassium intake in the Dietary Reference Intakes for Japanese, 2020, considering a typical Japanese dietary pattern. We also suggest that an average urine Na/K ratio of 4 is a feasible target value to achieve a temporary goal of being below the mean values of the urine Na/K ratio across Japanese general populations. These recommendations apply mainly for apparently healthy individuals, but not for patients with specific conditions due to the lack of supporting data. Current evidence for the usefulness of measuring the urine Na/K ratio for the prevention or control of hypertension remains inconclusive and warrants further investigation.

Factors influencing the efficacy and safety of esaxerenone in hypertensive patients: a pooled analysis of five clinical studies on different comorbidities

This study aimed to identify factors associated with a strong home blood pressure (BP)-lowering effect of esaxerenone and the incidence of elevated serum potassium levels in hypertensive patients treated with esaxerenone. A pooled analysis of five multicenter, prospective, open-label single-arm studies was conducted, including 479 patients in the full analysis set (FAS) and 492 patients in the safety analysis set. Multivariate linear regression analysis of morning home systolic BP (SBP) and diastolic BP (DBP) changes from baseline to Week 12 in the FAS (primary endpoint) showed that male sex (estimated change 4.37 mmHg), office pulse rate ≥100 beats/min (25.10 mmHg), and calcium channel blocker (CCB) use as a basal antihypertensive agent (4.53 mmHg) were significantly associated with a positive estimated change (weaker BP-lowering effect) in morning home SBP. CCB use (3.70 mmHg) was associated with a positive estimated change in morning home DBP. Urine albumin-to-creatinine ratio 30 to <300 mg/gCr (-4.13 mmHg) was significantly associated with a negative estimated change (stronger BP-lowering effect) in morning home SBP. Based on multivariate logistic regression analysis, elevated baseline serum potassium level (≥4.5 vs < 4.5 mEq/L, odds ratio 13.502) was significantly associated with a high incidence of serum potassium level ≥5.5 mEq/L after esaxerenone treatment. In conclusion, factors associated with a strong BP-lowering effect of esaxerenone were female sex and use of renin-angiotensin system inhibitors as a basal antihypertensive drug. Patients with baseline serum potassium levels ≥4.5 mEq/L had an increased risk of developing elevated serum potassium levels (≥5.5 mEq/L) after esaxerenone treatment.

Exploratory study on the relationship between urinary sodium/potassium ratio, salt intake, and the antihypertensive effect of esaxerenone: the ENaK Study

Excessive salt intake is one of the causes of hypertension, and reducing salt intake is important for managing the risk of hypertension and subsequent cardiovascular events. Esaxerenone, a mineralocorticoid receptor blocker, has the potential to exert an antihypertensive effect in hypertensive patients with excessive salt intake, but evidence is still lacking, especially in clinical settings. We aimed to determine if baseline sodium/potassium ratio and baseline estimated 24-h urinary sodium excretion can predict the antihypertensive effect of esaxerenone in patients with essential hypertension inadequately controlled with an angiotensin receptor blocker (ARB) or a calcium channel blocker (CCB). This was an exploratory, open-label, interventional study with a 4-week observation period and a 12-week treatment period. Esaxerenone was orally administered once daily in accordance with the Japanese package insert. In total, 126 patients met the eligibility criteria and were enrolled (ARB subcohort, 67; CCB subcohort, 59); all were included in the full analysis set (FAS) and safety analysis. In the FAS, morning home systolic blood pressure (SBP)/diastolic blood pressure (DBP) significantly decreased from baseline to end of treatment (primary efficacy endpoint) (-11.9 ± 10.9/ - 6.4 ± 6.8 mmHg, both p < 0.001); a similar trend was observed in both subcohorts. Significant reductions were also shown in bedtime home and office SBP/DBP (all p < 0.001). Each BP change was consistent regardless of the urinary sodium/potassium ratio or estimated 24-h urinary sodium excretion at baseline. The urinary albumin-creatinine ratio (UACR) and N-terminal pro-brain natriuretic peptide (NT-proBNP) significantly decreased from baseline to Week 12 in the total population and both subcohorts. No new safety concerns were raised. Esaxerenone significantly decreased morning home, bedtime home, and office BP; UACR; and NT-proBNP in this patient population, regardless of concomitant ARB or CCB use. The antihypertensive effect of esaxerenone was independent of the urinary sodium/potassium ratio and estimated 24-h urinary sodium excretion at baseline.

The Association between Urinary Sodium-Potassium Ratio, Kidney Function, and Blood Pressure in a Cohort from the General Population

INTRODUCTION

Subclinical kidney dysfunction may contribute to salt-sensitive hypertension. We assessed the association between the urinary sodium-potassium ratio (Na/K ratio) and blood pressure (BP) in a general population cohort without diabetes, chronic kidney disease, cardiovascular disease, or treated hypertension. We investigated whether any such association was mediated by the kidney function markers measured glomerular filtration rate (mGFR), urinary albumin-creatinine ratio (ACR), and urinary epidermal growth factor-creatinine ratio (EGF-Cr).

METHODS

The Tromsø Study is a population-based study of inhabitants of the municipality of Tromsø, Northern Norway. Participants aged 50-62 years, without diabetes, chronic kidney disease, or cardiovascular disease, were invited to the substudy Renal Iohexol Clearance Survey in Tromsø 6 (RENIS-T6; 2007-09). For the present study, we excluded participants reporting the use of 1 or more antihypertensive agents, leaving 1,311 RENIS-T6 participants for a cross-sectional analysis. We measured office BP, 24-h ambulatory blood pressure (ABP), and mGFR using iohexol clearance. Na/K ratio, ACR, and EGF-Cr were measured in morning urine samples.

RESULTS

Urinary Na/K ratio was significantly associated with systolic office BP and ABP independently of cardiovascular risk factors and kidney function markers. A one-standard deviation unit increase in the Na/K ratio was associated with increased systolic ABP by 1.0 (0.3-1.6) mm Hg. Urinary Na/K ratio showed a stronger association with office BP than ABP. EGF-Cr, ACR, and mGFR did not mediate the relationship between urinary Na/K ratio and systolic BP.

CONCLUSIONS

In a representative sample of the middle-aged North-European population without diabetes, chronic kidney disease, cardiovascular disease, or treated hypertension, there was a consistent association between urinary Na/K ratio and BP. The association with BP was not mediated through kidney function measures, suggesting a relationship between a diet with high sodium and low potassium and higher BP regardless of kidney function.

Excessive dietary sodium intake augments long-term risk of atrial fibrillation in older adults with hyperglycemia: A community-based prospective cohort study

AIM

Studies investigating the association between sodium intake and new-onset atrial fibrillation (AF) have come to controversial results. This study aimed to assess the effect of excessive sodium intake on new-onset AF in individuals with hyperglycemia.

METHODS

Between April 2007 and November 2011, 2841 community-dwelling individuals aged 60 years and older were recruited from the Shandong area, China. Dietary sodium intake was estimated using 24-hour urine collection within seven consecutive days. Fasting plasma glucose (FPG) and glycated hemoglobin (HbA1c) were assessed. New-onset AF was diagnosed using ICD-10 with codes I48 (I48.0 - I48.9) during follow-up.

RESULTS

The findings were that excessive sodium intake significantly and independently increased the risk of new-onset AF in older adults with hyperglycemia: hazard ratio (HR) 1.525 [95% confidence interval 1.147;2.029] adjusted P = 0.004. The risk of new-onset AF increased by 29.3% (HR 1.293 [1.108;1.509] adjusted P = 0.001) with a one-standard deviation increase in sodium intake. Excessive sodium intake synergistically interacted with hyperglycemia on the increased risk of new-onset AF (HR 1.599 [1.342;1.905] adjusted P < 0.001 for FPG and HR 1.516 [1.271;1.808] adjusted P < 0.001 for HbA1c).

CONCLUSION

Our findings indicate that excessive sodium intake independently enhances the risk of new-onset AF among patients with hyperglycemia. A sodium-restricted diet may perhaps result in a multiplier effect on reducing the risk of new-onset AF.

The damaging duo: Obesity and excess dietary salt contribute to hypertension and cardiovascular disease

Hypertension is a primary risk factor for cardiovascular disease. Cardiovascular disease is the leading cause of death among adults worldwide. In this review, we focus on two of the most critical public health challenges that contribute to hypertension-obesity and excess dietary sodium from salt (i.e., sodium chloride). While the independent effects of these factors have been studied extensively, the interplay of obesity and excess salt overconsumption is not well understood. Here, we discuss both the independent and combined effects of excess obesity and dietary salt given their contributions to vascular dysfunction, autonomic cardiovascular dysregulation, kidney dysfunction, and insulin resistance. We discuss the role of ultra-processed foods-accounting for nearly 60% of energy intake in America-as a major contributor to both obesity and salt overconsumption. We highlight the influence of obesity on elevated blood pressure in the presence of a high-salt diet (i.e., salt sensitivity). Throughout the review, we highlight critical gaps in knowledge that should be filled to inform us of the prevention, management, treatment, and mitigation strategies for addressing these public health challenges.