Morning Fasting Urine Samples Research Articles

Associations between 24-hour urinary sodium excretion and all-cause mortality in adults living in north China

Objective: To investigate the associations between 24-hour urinary sodium excretion (24hUNaE) and all-cause mortality in adult Northern Chinese population. Methods: Data from this study were derived from the prospective urban and rural epidemiology (PURE) study in north China. Baseline information of all participants were obtained by face to face interview through trained research staffs based on questionnaires, and morning fasting urine samples of participants were collected to estimate 24hUNaE and 24-hour potassium excretion (24hUKE). Multivariable frailty Cox regression models were used to explore the association between 24hUNaE (<3.00, 3.00-3.99, 4.00-4.99, 5.00-5.99 and ≥6 g/d) and all-cause death. Results: A total of 27 310 participants were included in this study. The mean 24hUNaE was (5.84±1.73) g/d. After a median follow-up of 8.8 years, 1 024 participants died (3.7%), including 390 cardiovascular related deaths and 591 non-cardiovascular related deaths. The cause of death of the remaining patients could not be determined. Using 24hUNaE level of 4.00-4.99 g/d as the reference group, after fully adjustment, 24hUNaE ≥6.00 g/d was associated with an increased risk of all-cause death (HR=1.24, 95%CI: 1.02-1.49) and cardiovascular related death (HR=1.39, 95%CI: 1.02-1.88). 24hUNaE<3.00 g/d was associated with increased risk of all-cause mortality (HR=1.38, 95%CI: 0.96-1.99). There was no significant association between 24hUNaE and non-cardiovascular related death. Furthermore, using the combination of 24hUNaE 4.00-4.99 g/d and 24hUKE≥2.11 g/d as the reference group, the highest risk occurred in participants with the combination of low sodium (<3.00 g/d) and low potassium (<2.11 g/d). Conclusion: 24hUNaE equal or higher than 6 g/d or lower than 3 g/d is associated with increased risk of all-cause mortality and cardiovascular related death in Northern Chinese population. Besides, moderate sodium intake in combination with increased potassium intake might reduce the risk of all-cause death.

Performance of equations for estimation of 24-hour urinary sodium from morning fasting urine samples in a multisite study in India.

Background Dietary salt intake is an important modifiable risk factor for cardiovascular diseases. Estimation of 24-hour salt intake using morning urine samples needs to be validated in the Indian context. We examined the performance of INTERSALT, Tanaka and Kawasaki equations for the estimation of 24-hour urinary sodium from morning fasting urine (MFU) samples. Methods We enrolled 486 adults aged 18-69 years from four regions of India with equal rural/urban and sex representation to provide 24-hour urine samples. The next day, a MFU sample was obtained. Based on the volume and sodium content of the 24-hour urine sample, 24-hour sodium excretion (reference method) was calculated. Sodium levels in the MFU samples were measured along with other parameters required, and the above equations were used to estimate 24-hour urinary sodium levels. Intraclass correlation coefficient (ICC) was used to assess the degree of agreement between the estimates from the reference method and the three equations. Bland-Altman (BA) plots were used to identify systematic bias and limits of agreement. A difference of 1 g of salt (0.39 g of sodium) between the mean salt intake by 24-hour urine and as estimated by equations was considered acceptable. Results A total of 346 participants provided both the samples. The mean (SD) daily salt intake estimated by the 24-hour urine sample method was 9.9 (5.8) g. ICC was low for all the three equations: highest for Kawasaki (0.16; 95% CI 0.05-0.26) and least for Tanaka (0.12; 0.02-0.22). Only Tanaka equation provided estimates within 1 g of measured 24-hour salt intake (-0.36 g). BA plots showed that as the mean values increased, all the three equations provided lower estimates of salt intake. Conclusion Tanaka equation provided acceptable values of 24-hour salt intake at the population level. However, poor performance of all the equations highlights the need to understand the reasons and develop better methods for the measurement of sodium intake at the population level.

Association of Urinary Sodium Excretion and Diabetic Kidney Disease in Patients With Type 2 Diabetes Mellitus: A Cross-Sectional Study.

BackgroundDiabetic kidney disease (DKD) is the leading cause of end-stage kidney disease worldwide. Epidemiological evidence of the association between urinary sodium excretion and the presence of DKD in patients with type 2 diabetes mellitus (T2DM) has not yet been well established.MethodsWe performed a cross-sectional study of 1545 patients with T2DM over aged 20 years old from January 2018 to December 2020. Urinary sodium excretion was measured by 24-hour urine samples in inpatients and morning fasting urine samples in outpatients. The associations between urinary sodium excretion and the risks of DKD were examined using stepwise regression analysis, logistic regression analysis and multivariable-adjusted restricted cubic splines (RCS).ResultsRegression analysis showed that urinary sodium was independently associated with urinary albumin to creatinine ratio (UACR) level (P = 0.006) and the risks of DKD (P = 0.042). In multivariable-adjusted RCS analysis, urinary sodium excretion was significantly associated with UACR in all patients (P = 0.008), and exhibited a J-shaped relationship. Logistic regression analysis showed that increased urinary sodium excretion was significantly associated with increased risks of DKD [OR (95% CI); 1.56 (1.07-2.27); P = 0.020]. However, the relationships between urinary sodium excretion and the risks of DKD and albuminuria showed no significance, after further adjustment for HOMA-IR and ba-PWV (brachial-ankle pulse wave velocity) (Both P > 0.05).ConclusionsHigher urinary sodium excretion level was associated with increased risks of DKD among patients with T2DM, dependent of vascular sclerosis and insulin resistance.

Association of Urinary Sodium Excretion and Left Ventricular Hypertrophy in People With Type 2 Diabetes Mellitus: A Cross-Sectional Study

BackgroundIt has been well documented that left ventricular hypertrophy (LVH) is highly associated with the incidence of cardiovascular disease (CVD). Evidence indicated that high sodium intake was closely related with LVH in general population. However, information is not available regarding the association between urinary sodium excretion and LVH in patients with type 2 diabetes mellitus (T2DM). This study aimed to explore the association between urinary sodium excretion and LVH in patients with T2DM.MethodsThis cross-sectional analysis included baseline data from 1,556 individuals with T2DM enrolled in the NanFang Prospective Diabetes Study (NFPDS). Urinary sodium excretion levels were measured from 24-hour urine samples of inpatients and morning fasting urine samples of outpatients. Left ventricular dimensions were assessed by echocardiography. The associations between urinary sodium excretion and the risks of cardiovascular events, LVH and left ventricular mass index (LVMI) were examined using linear regression analysis, logistic regression and restricted cubic splines (RCS).ResultsUrinary sodium excretion levels were positively associated with cardiometabolic risk factors, including systolic blood pressure, body mass index, waist circumference and LVMI (All P<0.001). Odds ratios of the highest quartile of urinary sodium excretion compared with the lowest quartile were 1.80 (95% CI, 1.28-2.54; P=0.001) for LVH and 1.77 (95% CI, 1.06-2.94; P=0.028) for CVD, after adjusted for demographics, lifestyle risk factors and cardiovascular risk factors. Multivariable-adjusted RCS analysis of the association between urinary sodium excretion and LVMI showed a significant association (P=0.001) and lacked evidence of a nonlinear association (P=0.406).ConclusionThis study indicated that high urinary sodium excretion was independently associated with increased risk of LVH and CVD in patients with T2DM, suggesting that control of sodium intake may be valuable for the prevention of diabetic cardiovascular complications.

Associations of estimated 24-h urinary sodium excretion with mortality and cardiovascular events in Chinese adults: a prospective cohort study.

To investigate the associations of sodium excretion with blood pressure, mortality and cardiovascular diseases in Chinese population. We studied 39 366 individuals aged 35-70 years from 115 urban and rural communities in 12 centers across mainland China. Trained research staff conducted face-to-face interview to record baseline information of all participants based on questionnaires, and collected their morning fasting urine samples to estimate 24-h sodium excretion (24hUNaE). Multivariable frailty Cox regression accounting for clustering by centre was performed to examine the association between estimated 24hUNaE and the primary composite outcome of death and major cardiovascular events in a Chinese population. Mean 24hUNaE was 5.68 (SD 1.69) g/day. After a median follow-up of 8.8 years, the composite outcome occurred in 3080 (7.8%) participants, of which 1426 (3.5%) died and 2192 (5.4%) suffered from cardiovascular events. 24hUNaE was positively associated with increased SBP and DBP. Using the 24hUNaE level of 4-4.99 g/day as the reference group, a 24hUNaE of either lower (<3 g/day) or higher (≥7 g/day) was associated with an increased risk of the composite outcome with a hazard ratio of 1.22 (95% confidence interval: 1.01-1.49) and 1.15 (95% confidence interval: 1.01-1.30), respectively. A similar trend was observed between 24hUNaE level and risk of death or major cardiovascular events. These findings support a positive association between estimated urinary sodium excretion and blood pressure, and a possible J-shaped pattern of association between sodium excretion and clinical outcomes, with the lowest risk in participants with sodium excretion between 3 and 5 g/day.

Estimating the urinary sodium excretion in patients with chronic kidney disease is not useful in monitoring the effects of a low-salt diet

BackgroundSeveral epidemiologic studies have suggested that the urine sodium excretion (USE) can be estimated in lieu of performing 24-hour urine collection. However, this method has not been verified in patients with chronic kidney disease (CKD) or in an interventional study. The purpose of this study was to evaluate the usefulness of estimating USE in a prospective low-salt diet education cohort (ESPECIAL).MethodsA new formula was developed on the basis of morning fasting urine samples from 228 CKD patients in the ESPECIAL cohort. This formula was compared to the previous four formulas in the prediction of 24-hour USE after treatment with olmesartan and low-salt diet education.ResultsMost previously reported formulas had low predictability of the measured USE based on the ESPECIAL cohort. Only the Tanaka formula showed a small but significant bias (9.8 mEq/day, P < 0.05) with a low correlation (r = 0.34). In contrast, a new formula showed improved bias (−0.1 mEq/day) and correlation (r = 0.569) at baseline. This formula demonstrated no significant bias (−1.2 mEq/day) with the same correlation (r = 0.571) after 8 weeks of treatment with olmesartan. Intensive low-salt diet education elicited a significant decrease in the measured USE. However, none of the formulas predicted this change in the measured urine sodium after diet adjustment.ConclusionWe developed a more reliable formula for estimating the USE in CKD patients. Although estimating USE is applicable in an interventional study, it may be unsuitable for estimating the change of individual sodium intake in a low-salt intervention study.

Urinary biomarkers as indicator of chronic inflammation and endothelial dysfunction in obese adolescents

BackgroundObesity is a pro-inflammatory state that may predispose patients to acute coronary syndrome characterized by chronic low grade inflammation resulting in endothelial dysfunction (ED). The aim of the study was to evaluate urinary biomarkers of inflammation and ED in adolescents with obesity.MethodsSixty three subjects were recruited for the study. Twenty healthy adolescents with normal body mass (NW), 14 overweight (OW), 29 obese (OA) subjects were selected. An EndoPat 2000 device was used to measure the reactive hyperemia index (RHI). First morning fasting urine samples were tested for interleukin 6 (IL-6), endothelin 1 (ET-1), alpha-1-acid glycoprotein (AGP), tumor necrosis factor- α (TNF-α) and corrected to urinary creatinine.ResultsUrinary TNF-α was significantly higher in OA group (52.4 ± 15.3 pg/mg) compared to adolescents with NW (14.1 ± 1.2 pg/mg, P = 0.04). ET-1 levels were found to be higher in OW (5.18 ± 1.6 pg/mg) compared with NW (3 · 47 ± 0.3 pg/mg, P = 0.24); and higher in OA (8.48 ± 3.1 pg/mg) compared to both NW (P = 0.19) and OW (P = 0.40). Similarly a higher AGP level was observed in OW (864.8 ± 156 ng/mg) and OA (808.3 ± 186 ng/mg) compared to NW (653 ± 69 ng/mg) (P = 0.16 & 0.49 respectively). Inflammatory markers namely, TNF-α, IL-6 and AGP significantly and positively correlated with each other and with ET-1, a marker for endothelial dysfunction. This significant correlation was also observed when tested separately in the subgroups (NW, OW and OA). There were no differences in RHI levels among the study groups.ConclusionUrinary TNF-alpha is significantly elevated in obese adolescents and correlates with urinary ET-1, which is recognized as a biomarker for endothelial dysfunction. Since obesity is a chronic inflammatory state, elevated urinary TNF-alpha might be used as a non invasive tool to monitor the level of that inflammation.

OS 03-07 URINARY SODIUM EXCRETION AND RISK OF CARDIOVASCULAR EVENTS IN CHINESE POPULATION

Abstract Evidence shows that a sodium intake between 3 g per day and 6 g per day was associated with the lowest risk of death and cardiovascular events in global population. However, the optimal range of sodium intake for cardiovascular health in China is still controversial. We enrolled individuals from 115 urban and rural communities in 12 areas across China mainland. Trained local staff recorded baseline information from 43034 participants with interview-based questionnaires, and obtained morning fasting urine samples to estimated 24-hour sodium (used as a surrogate for intake). We examined the association between estimated urinary sodium excretion and the composite outcome of death and major cardiovascular events in Chinese population. The mean estimated sodium excretion was 5.84 g per day. With a median follow-up of 4.00 years, the composite outcome occurred in 916 (2.13%) participants, of which 597 (1.39%) died and 476 (1.11%) suffered from cardiovascular diseases. As compared with an estimated sodium excretion of 5.00 to 6.99 g per day (reference range), a higher estimated sodium excretion ( 8.00 g per day) was associated with an increased but not significant risk of the composite outcome (odds ratio, 1.15; 95% confidence interval [CI], 0.82 to 1.61), as well as that with an estimated sodium excretion below 4.00 g per day (odds ratio, 1.21; 95% CI, 0.93 to 1.58). We recorded similar trend in death, but major cardiovascular events had a different tendency. An estimated sodium intake between 4 g per day and 7 g per day was associated with a lower risk of death and cardiovascular events in China. The recommended daily intake of sodium is 1 g larger than that suggested by former study, because Asian people, especially Chinese, generally eat more salt than other countries, and the tolerance of sodium may be higher.

The association of hypercalciuria and hyperuricosuria with vesicoureteral reflux in children.

One of the important complications of vesicoureteral reflux (VUR) is the development of urolithiasis. Identifying factors involved in development of urolithiasis in children with VUR is immensely important. This study was conducted to determine the association between hypercalciuria and hyperuricosuria with VUR in children. One-hundred children with VUR (case group) were compared to 100 healthy children (control group) in terms of hypercalciuria and hyperuricosuria. To measure these markers, random morning fasting urine samples were used. Data were analyzed using statistical tests. Hypercalciuria and hyperuricosuria frequencies, and also urine calcium/creatinine (Ca/Cr) and urine uric acid/creatinine (UA/Cr) ratios were significantly higher in the case group compared to the control group (P<0.05). A significant difference was found between hypercalciuria and hyperuricosuria in severity of VUR (P<0.05). A positive correlation was observed between hypercalciuria and hyperuricosuria and severity of VUR (P<0.05). The present study showed that there is association between hypercalciuria, hyperuricosuria and VUR in children. It is recommended to adopt measures to prevent the development of urolithiasis in VUR patients.

Urinary Sodium and Potassium Excretion, Mortality, and Cardiovascular Events

BackgroundThe optimal range of sodium intake for cardiovascular health is controversial.MethodsWe obtained morning fasting urine samples from 101,945 persons in 17 countries and estimated 24-hour sodium and potassium excretion (used as a surrogate for intake). We examined the association between estimated urinary sodium and potassium excretion and the composite outcome of death and major cardiovascular events.ResultsThe mean estimated sodium and potassium excretion was 4.93 g per day and 2.12 g per day, respectively. With a mean follow-up of 3.7 years, the composite outcome occurred in 3317 participants (3.3%). As compared with an estimated sodium excretion of 4.00 to 5.99 g per day (reference range), a higher estimated sodium excretion (≥7.00 g per day) was associated with an increased risk of the composite outcome (odds ratio, 1.15; 95% confidence interval [CI], 1.02 to 1.30), as well as increased risks of death and major cardiovascular events considered separately. The association between a high estimated sodium excretion and the composite outcome was strongest among participants with hypertension (P=0.02 for interaction), with an increased risk at an estimated sodium excretion of 6.00 g or more per day. As compared with the reference range, an estimated sodium excretion that was below 3.00 g per day was also associated with an increased risk of the composite outcome (odds ratio, 1.27; 95% CI, 1.12 to 1.44). As compared with an estimated potassium excretion that was less than 1.50 g per day, higher potassium excretion was associated with a reduced risk of the composite outcome.ConclusionsIn this study in which sodium intake was estimated on the basis of measured urinary excretion, an estimated sodium intake between 3 g per day and 6 g per day was associated with a lower risk of death and cardiovascular events than was either a higher or lower estimated level of intake. As compared with an estimated potassium excretion that was less than 1.50 g per day, higher potassium excretion was associated with a lower risk of death and cardiovascular events. (Funded by the Population Health Research Institute and others.)