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

Meta-analysis guided development of a standard artificial urine

In this study, we present the first meta-analysis of human urine reported in the literature, drawing data from a total of 35 articles with a combined participant count of 14,021. Through this analysis, we have developed an artificial urine (AU) composition that can be adjusted within typical physiological parameters for in vitro applications. Our findings demonstrate the utility of this AU in determining the solubility of nitrofurantoin, particularly in the context of crystalluria. Notably, we observe that in saline, nitrofurantoin solubility, within the framework of its urinary pharmacokinetics, suggests a risk of crystalluria. However, in AU, this risk is mitigated due to complexation with urea. More broadly, we anticipate that our developed formulation will serve as a foundation for translational studies across biomedical and pharmaceutical sciences.

Association of Dietary Sodium-to-Potassium Ratio with Cardiometabolic Risk Factors in Korean Adults: Findings from the Korean National Health and Nutrition Examination Survey

High-sodium and low-potassium intakes are interdependently linked to hypertension and cardiovascular diseases. We investigated the associations of dietary sodium-to-potassium (Na/K) ratio with cardiometabolic risk factors in 12,996 Korean adults (≥30 years) from the Korean National Health and Nutrition Examination Survey Ⅶ (2016-2018). Food intake was assessed through 24 h dietary recall data. Participants were divided into thirds based on their dietary Na/K ratio, with mean molar Na/K ratios of 1.11 (low), 1.92 (medium), and 3.21 (high). Although no significant associations were found between the dietary Na/K level and the risk of hypertension, obesity, and diabetes in all participants, the high Na/K ratio group had a higher risk of hypertension compared to the low Na/K ratio group in older adults (≥65 years) after adjusting for confounding factors (odds ratio = 1.38, 95% confidence interval: 1.10-1.72). Moreover, a higher Na/K ratio was associated with an increased risk of metabolic syndrome (MetS) in all participants (p for trend = 0.0020). Within MetS components, abdominal obesity, elevated triglycerides, and elevated blood pressure were positively associated with the Na/K level. The food groups positively associated with a lower Na/K ratio were fruits, unsalted vegetables, nuts, potatoes, and dairy products. These findings suggest that a high dietary Na/K ratio may be an important risk factor for hypertension in older adults and MetS in all adults.

Impact of urinary sodium excretion on the prevalence and incidence of metabolic syndrome: a population-based study

OBJECTIVE

To evaluate the association of metabolic syndrome (MetS) risk with 24-hour urinary sodium excretion (24hUNaE) estimated from spot urine samples.

DESIGN

Serial cross-sectional studies were conducted, and those with multiple repeated examinations were used to assess the MetS incidence risk.

SETTING AND PARTICIPANTS

A health check-up programme was conducted between 2018 and 2021 and enrolled 59 292 participants to evaluate the relationship between MetS risk and 24hUNaE in the Third Xiangya Hospital, Changsha, China. Among these participants, 9550 had at least two physical examinations during this period, which were used to evaluate the association of a new occurrence of MetS with 24hUNaE.

OUTCOMES

Guidelines for the prevention and treatment of dyslipidaemia in Chinese adults (revised in 2016) were used to define prevalent and incident MetS.

RESULTS

The prevalence of MetS was 19.3% at the first check-up; among individuals aged ≤55 years, the risk was higher in men than women, while among older individuals, a similar prevalence was observed in both sexes. A significant increase in MetS prevalence was observed per unit increase in 24hUNaE (adjusted OR (AOR) 1.11; 95% CI 1.09 to 1.13), especially for the prevalence of central obesity and elevated blood pressure. Additionally, 27.4% of the participants among the 7842 participants without MetS at the first check-up (male vs female: 37.3% vs 12.9%) were found to have a new occurrence of MetS at the second, third and/or fourth check-ups. A 25% increase in MetS incidence was observed per unit increase in 24hUNaE (95% CI 1.19 to 1.32), which was more prominent in the participants with a new occurrence of central obesity and elevated fasting blood glucose.

CONCLUSIONS

Although the prevalence of MetS seemed stable, new occurrences of MetS remained high, which might result in MetS recurrence. The influence of sodium intake on MetS development is probably attributed to the increase in blood pressure and central obesity, but a new occurrence of MetS may develop through elevated blood glucose and central obesity.