Tanaka Formula Research Articles

ϵ$$ \epsilon $$‐Nash equilibrium of non‐cooperative Lagrangian dynamic games based on the average sub‐gradient robust integral sliding mode control

SummaryIn non‐cooperative multi‐player games, an average sub‐gradient (ASG) strategy for finding an ‐Nash equilibrium. For convex (but not necessarily strictly convex) individual cost functions, the function convergence of the multi‐player game is demonstrated. Applying Tanaka's formula that characterizes the Nash equilibrium leads to finding the strategy for each player. A min‐max formulation defines the corresponding solution for each player. The main result is proving the reachability of the desired regime, obtaining an explicit upper bound for Tanaka's function decrement. Detailed analyses for two‐player and multi‐player games are developed. For a class of two‐player games with a convex performance function, a set of numerical studies shows the applicability of the proposed method. So, the tracking of the arm in 3‐links robot is considered as an illustrative example.

Sodium and potassium excretion and its association with cardiovascular disorders in Mexican adults.

Worldwide, as well as in Mexico, the leading cause of death is cardiovascular disease (CVD). Hypertension is the main risk factor for CVD; about 50% of the adult population suffers from this condition. High sodium (Na) intake combined with low potassium (K) intake can trigger cardiovascular disorders such as high blood pressure (BP). The aim of this study was to estimate the mean excretion of Na and K in Mexican adults using a spot urine sample, and its association with cardiovascular disorders. Information on 2,778 adults, 20-59 years of age, who participated in ENSANUT-2016 was analyzed. Na and K were estimated using Tanaka formulae. Biomarkers such as glucose, total cholesterol, triglycerides, HDL cholesterol and LDL cholesterol, and anthropometry were measured. Mean Na was 3,354 mg/day (95%CI: 3,278, 3,429), 1,440 mg/day of K (95%CI: 1,412, 1,469), and the Na-K ratio was 2.4. The excretion of Na was greater in adults with high BP (3,542 mg/day) compared to those with normal BP (3,296 mg/day). In adults with hypertension, excretion of K was 10% greater (1,534 mg/day) than in adults with normal BP (1,357 mg/day). In adults with moderate reduction of renal function, Na excretion was 22% less (2,772 mg/day) than in adults with normal kidney function (3,382 mg/day). The results of this study show that the cardiovascular health of Mexican adults is at risk, as they showed high Na excretion and low K excretion.

#842 Validation of the excessive salt intake screening questionnaire in CKD patients

Abstract Background and Aims Excessive salt intake is implicated in the progression of hypertension, chronic kidney disease (CKD), diabetic nephropathy, cardiovascular diseases, cerebrovascular diseases, and increased mortality. In Japan, average salt consumption surpasses the levels recommended by national guidelines and the WHO. However, individuals seldom have the chance to gauge their salt intake accurately. This study aimed to validate a screening tool initially developed by Sasaki et al. to identify individuals with excessive salt intake using health check-up data from Asahi City, Chiba Prefecture, Japan. Method This study was conducted as a part of the Cities Changing Diabetes (CCD). CCD is Novo Nordisk's commitment to drive action against type 2 diabetes and obesity in cities globally. It is a partnership program to accelerate the prevention of diabetes and obesity by addressing the systemic change in urban environments. Participants of this study were drawn from specific health examinations in Asahi City. Consent was obtained, and dialysis patients were excluded. Spot urine samples were analyzed for sodium and creatinine to estimate daily salt intake via Tanaka's formula. The screening tool incorporated risk factors such as age, gender, Body Mass Index (obesity), hypertension (use of antihypertensive drugs), frequency of soup intake, saltiness of home-cooked meals compared to restaurants, efforts to reduce salt intake, and frequency of dining out. The primary outcome was excessive salt intake, defined as an intake exceeding one standard deviation above the mean. Discrimination was assessed using the Area Under the Curve (AUC), while calibration was evaluated with a calibration plot and the Hosmer-Lemeshow test. Results Of the 1532 CKD participants, the mean age was 76.3 years, with males comprising 46%. The average daily salt intake was 9.3 g (SD: 2.39), and the estimated Glomerular Filtration Rate (GFR) was 50.6 ml/min/1.73 m² (SD: 14.5). The distribution of CKD stages included 1198 stage 3a, 285 stage 3b, 43 stage 4, and 5 stage 5 patients. The AUC of screening tool was 0.65 (95% CI: 0.61 to 0.69), and its calibration slope (with an intercept) was 0.98 (95% CI: 0.72 to 1.25). The Hosmer-Lemeshow test yielded a p-value of 0.626. Conclusion The predictive capability of the existing model for excessive salt intake was limited in the CKD population, which may suggest a need for a screening method distinct from that used in the general population. Factors such as changes in sodium excretion due to reduced renal function and the effects of diuretics should also be considered when interpreting these results. Integrating this questionnaire into routine health check-ups could enhance dietary monitoring and intervention, potentially attenuating the progression of CKD and its associated complications. There remains scope for further refinement of the tool's accuracy by incorporating additional predictors.

Evaluation of three prediction formulas of 24-hour urinary sodium excretion in Chinese residents: a systematic review and meta-analysis.

To determine the appropriateness of three widely used formulas estimating 24-h urinary Na (24hUNa) from spot urine samples in the Chinese population. Systematic review and meta-analysis. Literature review was conducted to identify studies for estimating 24hUNa using the Kawasaki, Tanaka and INTERSALT formulas simultaneously in PubMed, Embase and the Cochrane library databases. The mean difference (MD) and correlation coefficients (r) between measures and estimates from different formulas were assessed. Information extraction and quality assessment were performed in thirteen studies involving 8369 subjects. Two studies which affected the overall robustness were excluded in the 'leave-one-out' sensitivity analyses. Within the final meta-analysis included eleven studies and 7197 participants, 36·07 mmol/d (95 %CI 16·89, 55·25) of MD was observed in the Kawasaki formula, and -19·62 mmol/d (95 %CI -37·37, -1·87) in the Tanaka formula and -35·78 mmol/d (95 %CI -50·76, -20·80) in the INTERSALT formula; a pooled r-Fisher's Z of 0·39 (95 %CI 0·32, 0·45) in the Kawasaki formula, 0·43 (95 %CI 0·37, 0·49) in the Tanaka formula and 0·36 (95 %CI 0·31, 0·42) in the INTERSALT formula. Subgroup analyses were conducted to explore the possible factors affecting the accuracy of the formula estimation from three mainly aspects: population types, Na intake levels and urine specimen types. The meta-analysis suggested that the Tanaka formula performed a more accurate estimate in Chinese population. Time of collecting spot urine specimens and Na intake level of the sample population might be the main factors affecting the accuracy of the formula estimation.

Tanaka Formula and Local Time for a Class of Interacting Branching Measure-valued Diffusions

Tanaka Formula and Local Time for a Class of Interacting Branching Measure-valued Diffusions

An infinite-dimensional representation of the Ray-Knight theorems

The classical Ray-Knight theorems for Brownian motion determine the law of its local time process either at the first hitting time of a given value a by the local time at the origin, or at the first hitting time of a given position b by Brownian motion. We extend these results by describing the local time process jointly for all a and all b, by means of stochastic integral with respect to an appropriate white noise. Our result applies to µ-processes, and has an immediate application: a µ-process is the height process of a Feller continuous-state branching process (CSBP) with immigration (Lambert [10]), whereas a Feller CSBP with immigration satisfies a stochastic differential equation driven by a white noise (Dawson and Li [7]); our result gives an explicit relation between these two descriptions and shows that the stochastic differential equation in question is a reformulation of Tanaka's formula.

Effect of dipeptidyl peptidase-4 inhibitors on glycated hemoglobin levels relies on dietary sodium intake

AimsSodium load increases endogenous glucagon-like peptide-1 (GLP-1) levels in humans. Therefore, patients with an increased amount of dietary sodium intake are supposed to have higher endogenous GLP-1 levels compared to those with less dietary sodium intake. Therefore, it can be hypothesized that patients with type 2 diabetes mellitus (T2DM) with more dietary sodium intake show better dipeptidyl peptidase-4 inhibitor (DPP-4i) effect on glycemic control because of the expected higher GLP-1 level. Thus, we performed a single-center cohort study to explore this idea. MethodsMedical records of patients with T2DM prescribed DPP-4i in the last 11 years were investigated. Dietary sodium intake was measured before the DPP-4i prescription with Tanaka's formula using casual spot urine samples. The effect of DPP-4i on glycemic control was estimated by the subtraction of glycated hemoglobin (HbA1c) before DPP-4i initiation from HbA1c 1 year after DPP-4i administration. We analyzed 50 patients. ResultsDPP-4i improved HbA1c by −0.41% ± 0.66%. The effect of DPP-4i on glycemic control was significantly negatively correlated with the dietary sodium intake (r = −0.400). Thus, the more dietary sodium intake, the better the glycemic control by DPP-4i. ConclusionsThus, patients can expect better plasma glucose control by DPP-4is if patients are taking increased dietary sodium intake.

A Novel Hybrid Approach for Computing Electromagnetic Scattering from Objects with Honeycomb Structures

We propose in this paper a novel hybrid numerical modeling method for computing electromagnetic scattering from inhomogeneous targets containing honeycomb structures. In the proposed approach, the whole honeycomb structure is divided into the inner and outer two subregions. Each thin wall of a unit cell in the outer subregion is replaced by a zero-thickness surface, with the aid of a resistive sheet boundary condition (RSBC) to describe the electric and magnetic field discontinuities across the surface. Each unit cell in the inner subregion is homogenized by using the Hashin–Shtrikman and the Mori–Tanaka formulae. The two subregions are further divided into smaller subdomains by introducing the Robin-type transmission condition to couple subregion interfaces, as well as subdomain interfaces. The whole solution region is then discretized and solved using the nonconformal domain decomposition-based hybrid finite element–boundary integral–multilevel fast multipole algorithm (FE-BI-MLFMA). The numerical results demonstrate that the proposed approach exhibits a high accuracy, efficiency, and flexibility. Solutions of scattering by a wing-like object and a practical unmanned aerial vehicle (UAV) model with honeycomb radar-absorbing structures are presented, showing the superior performance of the proposed algorithm.

A Meyer-Itô formula for stable processes via fractional calculus

The infinitesimal generator of a one-dimensional strictly alpha -stable process can be represented as a weighted sum of (right and left) Riemann-Liouville fractional derivatives of order alpha and one obtains the fractional Laplacian in the case of symmetric stable processes. Using this relationship, we compute the inverse of the infinitesimal generator on Lizorkin space, from which we can recover the potential if alpha in (0,1) and the recurrent potential if alpha in (1,2). The inverse of the infinitesimal generator is expressed in terms of a linear combination of (right and left) Riemann-Liouville fractional integrals of order alpha . One can then state a class of functions that give semimartingales when applied to strictly stable processes and state a Meyer-Itô theorem with a non-zero (occupational) local time term, providing a generalization of the Tanaka formula given by Tsukada [1]. This result is used to find a Doob-Meyer (or semimartingale) decomposition for |X_t - x|^{gamma } with X a recurrent strictly stable process of index alpha and gamma in (alpha -1,alpha ), generalizing the work of Engelbert and Kurenok [2] to the asymmetric case.

S-54-4: DIETARY SALT INTAKE ASSESSED BY SPOT URINARY SODIUM EXCRETION FROM CHILD TO ADULTHOOD IN A JAPANESE TOWN

In clinical practice, a high salt intake is strongly associated with elevation of blood pressure. To prevent and treat hypertension, it is important to restrict salt in one’s diet from child and adolescence. However, data are lacking regarding dietary salt intake from child to adulthood in general population. Therefore, we evaluated the dietary salt intake assessed by spot urinary sodium excretion from child to adulthood in a Japanese town. A total of 534 persons of both sexes, aged from 3 to 91 years were under study. The Tanaka formula was used to estimate 24-h urinary sodium excretion, which reflects salt intake. The average salt intake was 8.0 ± 2.7 g/day (n = 534); that of the men was 8.2 ± 2.8 g/day (n = 206), and that of the women was 7.8 ± 2.6 g/day (n = 249). When we assessed by age group, the average salt intake was 3.8 ± 2.2 g/day in 3 years old (n = 79), 6.8 ± 1.5 g/day in 11 years old (n = 36), 8.0 ± 1.5 g/day in 14 years old (n = 37), 8.6 ± 2.8 g/day in 20 s and 30 s (n = 37), 8.0 ± 1.7 g/day in 40 s (n = 24), 8.9 ± 2.2 g/day in 50 s (n = 32), 8.9 ± 2.1 g/day in 60 s (n = 108), 9.2 ± 1.9 g/day in 70 s (n = 182), and 9.0 ± 2.2 g/day in over 80 s (n = 22). Notably, dietary salt intake was over 6 g/day even in 11 years old. The salt intake was significantly higher in the older age group (P < 0.001 for trend) and was significantly associated with higher systolic and diastolic blood pressure. In conclusion, it is important to educate children, their parents, childcare professionals, and society about proper salt restriction and potassium supplementation, as well as to improve the food environment.

S-54-3: PREDICTION AND PREVENTION OF THE ONSET OF HYPERTENSION FROM THE VIEWPOINT OF ESTIMATED 24-HOUR SALT EXCRETION AND PHYSICAL FITNESS TEST

Objective: Both dietary salt and physical activity contribute substantially to development and progression of blood pressure elevation. Earlier detection of blood pressure change by daily simple procedures are effective for health promotion less expensively. We performed both longitudinal and cross-sectional observations for the subjects with annual comprehensive health checkup to test relationships among daily salt intake, physical activity, and blood pressure elevation. Methods: We performed following three observations. A)Body weights, interviewed salt intakes (i-NaCl), and estimated salt intakes (e-NaCl) for single spot urine (Tanaka formula) were measured and compared to blood pressure change monthly for one year in total 17,794 participants. B) To test significance of shared e-NaCl information to health promotions, we shared e-NaCl to total 98,908 participants individually and, subsequently, annual-mean e-NaCl was compared for 5 years. C) To test significance of physical activity for blood pressure elevations, we performed 5-year follow up study for total 22,972 participants to examine the onset of hypertension and physical activity as followings; duration of single-leg balance with eyes closed (sec), grip strength (kg), forward bending (cm), whole body reaction time (msec), vertical jump distance (cm), and supine leg-up (sec), respectively. Results: A) Only e-NaCl was found to have a strong correlation with the monthly mean systolic blood pressure as shown in a figure. B) By sharing e-NaCl information with participants, annual mean of e-NaCl decreased significantly from 9.22 g/day (male) and 8.79 g/day (female) in 2012 to 9.03 g/day (male) and 8.63 g/day (female) in 2017. C) Even when adjusted for gender, age, BMI, systolic and diastolic blood pressure of first year, single-leg balance with eyes closed and forward bending were significantly associated with the onset of hypertension. Conclusion: Since e-NaCl is affected by salt excretion due to sweating, it was presumed that the amount of salt to be excreted in urine correlated well with seasonal changes in blood pressure. In addition, e-NaCl measurement is a good tool that can be used for health guidance to examinees for their life style promotion. It was found that flexibility and a sense of equilibrium are related to the onset of blood pressure.

S-54-5: CHANGES IN ESTIMATED SALT AND POTASSIUM INTAKE AND SODIUM-TO-POTASSIUM RATIO USING SPOT URINE MEASUREMENTS: A 10-YEAR FOLLOW-UP OF NIPPON DATA2010

Background: Reducing dietary salt (sodium) intake and increasing potassium intake and sodium to potassium ratio (Na/K) are crucial in preventing hypertension. However, these changes by aging have not yet been evaluated in Japanese general population. Methods: NIPPON DATA2010 is a cohort study in the participants of the National Health and Nutrition Survey of Japan in 2010, we assessed changes in dietary sodium and potassium intake from 2010 to 2020 using spot urine. Of 2,732 participants in the 2010 survey, 667 participants (mean age 54.8 ± 8.2 years, women 59.1%) underwent spot urine measurements in both 2010 and 2020 survey. Using Tanaka formula, we estimated 24-hour salt intake (g/day) and potassium excretion (mg/day), and calculated sodium to potassium (Na/K) ratio (mmol/mmol) in spot urine for each participant. We assessed these changes from 2010 to 2020 by sex and age groups. Results: Change in estimated 24-hour salt intake from 2010 to 2020 was not a statistically significant in all groups (see table). Only estimated 24-hour potassium excretion showed a statistically significant increase in women and men ≧60 years, and the change showed a tendency towards statistical significance in men < 60 years. Na/K ratio was significantly reduced in women and men ≧60 years, not in men < 60 years. Conclusions: Potassium intake increased and dietary Na/K ratio decreased by 10-year aging in Japanese men and women, except for relatively younger men.

Evaluation Of Valid VO2max Criteria For Graded Exercise Testing In Cancer Survivors

INTRO: Using a metabolic cart (met cart) to obtain an individual's maximal oxygen consumption (VO2max) is considered the gold standard method of measurement. An accurate VO2max value is important in every population for individualized exercise prescriptions (ExRx), but specifically within the cancer population due to treatment status. Certain criteria must be met for a value to be considered a true VO2max. Utilizing gas analysis to track the changing respiratory exchange ratio (RER) and achieving >1.10 is the best criteria to determine if true max was obtained. Other maximal criteria such as 85% of heart rate max (HR) using the Tanaka formula and rate of perceived exertion (RPE) of >7 on the Modified Borg Scale also have the potential to be used as maximal criteria eliminating the need for a met cart. It is unknown if HR and RPE can be used independently as valid termination criteria in the cancer population during VO2max assessments. PURPOSE: To evaluate the frequency of achieving VO2max as determined by RER and alternate maximal criteria using HR and RER in a sample of cancer survivors. METHODS: Forty cancer survivors participated in the study. Subjects performed one GXT per week for three weeks using gas analysis. RER, HR, and RPE values were recorded. A total of 111 GXTs were used for data analysis. A Cochran’s Q test was used to determine if there were differences in the frequency of successful achievement of RER, HR, and RPE maximal criteria during the GXTs. RESULTS: Maximal criteria was successfully met in 95, 89, and 102 GXTs when evaluating RER, HR, and RPE, respectively. No significant differences occurred in the achievement of max between RER, HR, and RPE criteria (p < 0.061). CONCLUSION: The findings from this data set suggest that HR and RPE may be valid and suitable criteria for termination of a GXT if obtaining an RER value is not feasible or clinically practical. Cancer survivors experience toxicities such as skin irritation, muscular impairments, balance issues, peripheral neuropathy, and/or cancer related fatigue, making use of a met cart and mask potential impediments to maximal performance. Elimination of the met cart may allow the individual to advance further into a GXT leading to more accurate VO2max values and thus more accurate ExRx in the cancer population.

A Flexible and Efficient Method for the Analysis of Electromagnetic Scattering by Inhomogeneous Objects With Honeycomb Structures

We present in this letter an efficient numerical method for the analysis of electromagnetic scattering by inhomogeneous objects with arbitrarily oriented honeycomb radar absorbing structures. In this method, each cellular honeycomb structure is first homogenized as a diagonal anisotropic medium in local coordinate system by using a new hybrid Hashin–Shtrikman and Mori–Tanaka formula. Then, a Euler rotation matrix is employed for describing a honeycomb structure with arbitrary orientation in a global coordinate system by transforming a diagonal tensor into a general 3 × 3 tensor. Finally, the object with homogenized honeycomb structures are simulated by using the nonconformal domain decomposition finite element-boundary integral-multilevel fast multipole algorithm. Numerical examples are presented to demonstrate the accuracy, efficiency and capability of the proposed algorithm, including the scattering by a typical sandwich panel with honeycomb core, and a complicated fighter model which includes antenna array, dielectric radome and radar-absorbing honeycomb structure.

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.

Salt and potassium intake evaluated with spot urine and brief questionnaires in combination with blood pressure control status in hypertensive outpatients in a real-world setting.

Reducing salt and increasing potassium intake are recommended lifestyle modifications for patients with hypertension. The estimated 24-h urinary salt excretion value from spot urine using Tanaka's formula and the salt check-sheet scores, questionnaire-based scores of salt intake, are practical indices of daily salt intake. However, few studies have evaluated salt intake with these methods in hypertensive outpatients. We examined salt and potassium intake with the spot urine method and the salt check-sheet scores of hypertensive outpatients in a multi-facility, real-world setting and examined whether the salt or potassium intake evaluated with these methods related to inadequate blood pressure control. Hypertensive outpatients from 12 medical facilities in the Okinawa prefecture were enrolled from November 2011 to April 2014 (n = 1559, mean age 63.9 years, 46% women). The mean blood pressure, urinary salt excretion value, urinary potassium excretion value, and total score on the salt check-sheet were 129/75 mmHg, 8.7 g/day, 1.6 g/day, and 10.4 points, respectively. The urinary salt excretion value and total score on the salt check-sheet but not urinary potassium excretion value were associated with inadequate blood pressure control (≥140/90 mmHg). Higher body mass index, estimated glomerular filtration rate, urinary potassium excretion value, total score on the salt check-sheet, and presence of inadequate blood pressure control were associated with high urinary salt excretion (≥10.2 g/day). In conclusion, hypertensive outpatients with high urinary salt excretion values estimated using Tanaka's formula or with high scores on the salt check sheet may be candidates for more intensive salt reduction guidance.

Evaluation of Relationship between Mesiodistal Width of Permanent Canines and Premolars with Permanent Lower First Molars and Incisors for Space Analysis

Introduction: One of the simplest methods to predict mesiodistal width of permanent canines and premolars is using Tanaka and Johnston’s prediction formula; however, dental size varies according to race. The study aimed to examine the relationship between incisors mesiodistal width and mandibular first molar’s with mesiodistal width of maxillary and mandibular canines and premolars and to determine the reliability of Tanaka and Johnston prediction formula. Materials &amp; Methods: In the present cross-sectional study, 200 pairs of a dental cast of 12-25 years old were selected and the greatest mesiodistal width of canines and premolars crown in each jaw and incisors and mandibular first molars were measured with a digital caliper with 0.01 resolution. Data were analyzed using regression analysis, t-test (p value &lt; 0.05). Results: There was a significant statistical difference between actual width and Tanaka and Johnston prediction formula in the group under study (p value &lt; 0.001). Moreover, a new linear equation for the prediction of mesiodistal width of maxillary and mandibular canines and premolars based on mesiodistal width of lower incisors and mandibular first molars was developed using regression analysis. Conclusion: In statistical terms, Tanaka and Johnston’s prediction formula is not applicable for the population under study because maxillary estimated measures were a little high and mandibular estimated measures were a little low.

The first passage time on the (reflected) Brownian motion with broken drift hitting a random boundary

This paper studies the first passage times of a (reflected) Brownian motion with broken drift over a random boundary. The time-dependent Meyer–Tanaka formula allows us to obtain the formulas on the joint Laplace transform of the hitting time and hitting position. This paper extends the results of first rendezvous times of (reflected) Brownian motion and compound Poisson-type processes in Perry et al. (2004).

Urinary Sodium and Potassium, and Risk of Ischemic and Hemorrhagic Stroke (INTERSTROKE): A Case-Control Study.

BACKGROUNDAlthough low sodium intake (<2 g/day) and high potassium intake (>3.5 g/day) are proposed as public health interventions to reduce stroke risk, there is uncertainty about the benefit and feasibility of this combined recommendation on prevention of stroke.METHODSWe obtained random urine samples from 9,275 cases of acute first stroke and 9,726 matched controls from 27 countries and estimated the 24-hour sodium and potassium excretion, a surrogate for intake, using the Tanaka formula. Using multivariable conditional logistic regression, we determined the associations of estimated 24-hour urinary sodium and potassium excretion with stroke and its subtypes.RESULTSCompared with an estimated urinary sodium excretion of 2.8–3.5 g/day (reference), higher (>4.26 g/day) (odds ratio [OR] 1.81; 95% confidence interval [CI], 1.65–2.00) and lower (<2.8 g/day) sodium excretion (OR 1.39; 95% CI, 1.26–1.53) were significantly associated with increased risk of stroke. The stroke risk associated with the highest quartile of sodium intake (sodium excretion >4.26 g/day) was significantly greater (P < 0.001) for intracerebral hemorrhage (ICH) (OR 2.38; 95% CI, 1.93–2.92) than for ischemic stroke (OR 1.67; 95% CI, 1.50–1.87). Urinary potassium was inversely and linearly associated with risk of stroke, and stronger for ischemic stroke than ICH (P = 0.026). In an analysis of combined sodium and potassium excretion, the combination of high potassium intake (>1.58 g/day) and moderate sodium intake (2.8–3.5 g/day) was associated with the lowest risk of stroke.CONCLUSIONSThe association of sodium intake and stroke is J-shaped, with high sodium intake a stronger risk factor for ICH than ischemic stroke. Our data suggest that moderate sodium intake—rather than low sodium intake—combined with high potassium intake may be associated with the lowest risk of stroke and expected to be a more feasible combined dietary target.

Estimated 24-hour urinary sodium excretion as a risk factor for oxidative stress in Zambian adults: A cross-sectional study.

IntroductionPersistent oxidative stress predisposes to various non-communicable diseases (NCDs), whose occurrence is increasing in sub-Saharan Africa. The aim of this study was to evaluate the link between markers of oxidative stress and some risk factors for NCDs in a Zambian cohort.MethodsWe assessed oxidative stress by measuring 8-isoprostane (lipid oxidative stress) and 8-hydroxydeoxyguanosine (DNA oxidative stress). In addition, we measured mycotoxins (aflatoxin M1 and ochratoxin A), salt intake estimated from 24-hour sodium excretion calculated using the Tanaka and Kawaski formulae, and 1-hydroxypyrene (a metabolite of polycyclic aromatic hydrocarbons). Data on lifestyle risk factors were collected using questionnaires.ResultsIncluded were 244 participants; 128 (52%) were female and the median age was 48 years (IQR 39–58). The median level of 8-isoprostane was 0.13 ng/mg creatinine (IQR 0.08–0.23) while that of 8-hydroxydeoxyguanosine (8-OHdG) was 4 ng/mg creatinine (IQR 2–10). The median 24-hour sodium excretion was 21 g (IQR 16–25 g), with none being less than the 5 g recommended by WHO. Unadjusted urinary levels of 8-isoprostane were moderately correlated with 1-hydroxypyrene (Spearman r = 0.30, p<0.001) and estimated 24-hour urine sodium (Spearman r = 0.38, p<0.001). Urinary levels of 8-OHdG were not correlated with 1-hydroxypyrene, estimated 24-hour urine sodium, aflatoxin M1 or ochratoxin A (all p-values >0.05). Using logistic regression, adjusted and unadjusted 8-isoprostanes levels were associated with 1-hydroxypyrene (p = 0.02 and p = 0.001 respectively) and estimated 24-hour urine sodium method (p = 0.003 and p<0.001 respectively). However, only unadjusted 8-OHdG was associated with 1-hydroxypyrene (p = 0.03) and age (p = 0.007).ConclusionsEstimated 24-hour urinary sodium is high among Zambians and it is associated with lipid but not DNA oxidative stress. High exposure to polycyclic aromatic hydrocarbons is also associated with oxidative stress.