scholarly journals Urinary Sodium Excretion and Blood Pressure Relationship across Methods of Evaluating the Completeness of 24-h Urine Collections

Nutrients ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2772
Author(s):  
Abu Mohd Naser ◽  
Feng J. He ◽  
Mahbubur Rahman ◽  
K. M. Venkat Narayan ◽  
Norm R. C. Campbell

We compared the sodium intake and systolic blood pressure (SBP) relationship from complete 24-h urine samples determined by several methods: self-reported no-missed urine, creatinine index ≥0.7, measured 24-h urine creatinine (mCER) within 25% and 15% of Kawasaki predicted urine creatinine, and sex-specific mCER ranges (mCER 15–25 mg/kg/24-h for men; 10–20 mg/kg/24-h for women). We pooled 10,031 BP and 24-h urine sodium data from 2143 participants. We implemented multilevel linear models to illustrate the shape of the sodium–BP relationship using the restricted cubic spline (RCS) plots, and to assess the difference in mean SBP for a 100 mmol increase in 24-h urine sodium. The RCS plot illustrated an initial steep positive sodium–SBP relationship for all methods, followed by a less steep positive relationship for self-reported no-missed urine, creatinine index ≥0.7, and sex-specific mCER ranges; and a plateaued relationship for the two Kawasaki methods. Each 100 mmol/24-h increase in urinary sodium was associated with 0.64 (95% CI: 0.34, 0.94) mmHg higher SBP for self-reported no-missed urine, 0.68 (95% CI: 0.27, 1.08) mmHg higher SBP for creatinine index ≥0.7, 0.87 (95% CI: 0.07, 1.67) mmHg higher SBP for mCER within 25% Kawasaki predicted urine creatinine, 0.98 (95% CI: −0.07, 2.02) mmHg change in SBP for mCER within 15% Kawasaki predicted urine creatinine, and 1.96 (95% CI: 0.93, 2.99) mmHg higher SBP for sex-specific mCER ranges. Studies examining 24-h urine sodium in relation to health outcomes will have different results based on how urine collections are deemed as complete.

Author(s):  
Abu Mohd Naser ◽  
Feng J. He ◽  
Mahbubur Rahman ◽  
Norm R.C. Campbell

We evaluated the relationship between estimated 24-hour urinary sodium excretion from the Kawasaki, Tanaka, and INTERSALT (International Study of Sodium, Potassium, and Blood Pressure) formulas and blood pressure (BP). We pooled 10 034 person-visit data from 3 cohort studies in Bangladesh that had measured 24-hour urine sodium (m-24hUNa), potassium, creatinine excretion, and BP. We used m-24hUNa, potassium, and creatinine where necessary, rather than spot urine values in the formulas. Bland-Altman plots were used to determine the bias associated with formula-estimated sodium relative to m-24hUNa. We compared the sodium excretion and BP relationships from m-24hUNa versus formula-estimated sodium excretions, using restricted cubic spline plots for adjusted multilevel linear models. All formulas overestimated 24-hour sodium at lower levels but underestimated 24-hour sodium at higher levels. There was a linear relationship between m-24hUNa excretion and systolic BP, while estimated sodium excretion from all 3 formulas had a J-shaped relationship with systolic BP. The relationships between urine sodium excretion and diastolic BP were more complex but were also altered by using formulas. All formulas had associations with BP when a sex-specific constant sodium concentration was inserted in place of measured sodium. Since we used the m-24hUNa, potassium, and creatinine concentrations in formulas, the J-shaped relationships are due to intrinsic problems in the formulas, not due to spot urine sampling. Formula-estimated 24-hour urine sodium excretion should not be used to examine the relationship between sodium excretion and BP since they alter the real associations.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xiaofu Du ◽  
Le Fang ◽  
Jianwei Xu ◽  
Xiangyu Chen ◽  
Yamin Bai ◽  
...  

AbstractThe direction and magnitude of the association between sodium and potassium excretion and blood pressure (BP) may differ depending on the characteristics of the study participant or the intake assessment method. Our objective was to assess the relationship between BP, hypertension and 24-h urinary sodium and potassium excretion among Chinese adults. A total of 1424 provincially representative Chinese residents aged 18 to 69 years participated in a cross-sectional survey in 2017 that included demographic data, physical measurements and 24-h urine collection. In this study, the average 24-h urinary sodium and potassium excretion and sodium-to-potassium ratio were 3811.4 mg/day, 1449.3 mg/day, and 4.9, respectively. After multivariable adjustment, each 1000 mg difference in 24-h urinary sodium excretion was significantly associated with systolic BP (0.64 mm Hg; 95% confidence interval [CI] 0.05–1.24) and diastolic BP (0.45 mm Hg; 95% CI 0.08–0.81), and each 1000 mg difference in 24-h urinary potassium excretion was inversely associated with systolic BP (− 3.07 mm Hg; 95% CI − 4.57 to − 1.57) and diastolic BP (− 0.94 mm Hg; 95% CI − 1.87 to − 0.02). The sodium-to-potassium ratio was significantly associated with systolic BP (0.78 mm Hg; 95% CI 0.42–1.13) and diastolic BP (0.31 mm Hg; 95% CI 0.10–0.53) per 1-unit increase. These associations were mainly driven by the hypertensive group. Those with a sodium intake above about 4900 mg/24 h or with a potassium intake below about 1000 mg/24 h had a higher risk of hypertension. At higher but not lower levels of 24-h urinary sodium excretion, potassium can better blunt the sodium-BP relationship. The adjusted odds ratios (ORs) of hypertension in the highest quartile compared with the lowest quartile of excretion were 0.54 (95% CI 0.35–0.84) for potassium and 1.71 (95% CI 1.16–2.51) for the sodium-to-potassium ratio, while the corresponding OR for sodium was not significant (OR, 1.28; 95% CI 0.83–1.98). Our results showed that the sodium intake was significantly associated with BP among hypertensive patients and the inverse association between potassium intake and BP was stronger and involved a larger fraction of the population, especially those with a potassium intake below 1000 mg/24 h should probably increase their potassium intake.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
J Carter ◽  
F Re ◽  
I Hammami ◽  
T Littlejohns ◽  
M Arnold ◽  
...  

Abstract Background Randomised control trials have demonstrated direct positive and causal associations of 24-hr measurements of urinary sodium excretion on blood pressure. However, prospective studies, which often used spot (not 24-hr) measurements of urinary sodium, have reported J-shaped associations with higher risks of cardiovascular disease (CVD) at sodium intake <4 g/day. The reasons for the discrepant results are not fully understood, but have prompted some to question the World Health Organisation's recommendations to restrict sodium intake to <2.3g/day. Purpose We examined the effects of within-person variability in spot urinary sodium (UNa) measurements on immediate and delayed associations of UNa with blood pressure at baseline and at resurvey, and with incident cardiovascular disease in the UK Biobank (UKB). Methods Baseline spot urine samples were measured in 502,619 adults at baseline and in 20,346 participants who were resurveyed at 4 years after baseline. Linear regression was used to assess associations of baseline UNa measurements with systolic blood pressure (SBP; mmHg) at baseline and at resurvey. Cox regression was used estimate the associations between baseline measures of UNa with incident CVD events (recorded from linkage with hospital records). All analyses were adjusted for confounders and corrected for regression dilution bias. Results After excluding participants with prevalent diseases, the primary analyses involved 386,060 adults who were followed-up for a median of 7.8 years, during which ∼13,000 CVD events occurred. Estimated mean (SD) urinary sodium excretion was 77.4 mmol/L (SD 44.4, IQR = 42.8–103.7 mmol/L), and mean SBP/DBP were 137.5/82.3 (SD 18.5/10.1) mmHg, respectively. Within-person variability in UNa was high, with a self-correlation of 0.35 at 4 years between measurements. After adjustment for confounders and correction for regression dilution bias, a 100 mmol/L higher UNa was associated with an immediate 3.2 mmHg higher SBP (95% confidence interval [CI]: 2.8–3.6) in cross-sectional analyses (Figure 1). However, the corresponding associations of baseline UNa with SBP at resurvey was completely attenuated (p=0.20). The predicted risk of CVD was 1.06 (95% CI 1.06–1.07, p<0.001) for a 3.2 mmHg higher SBP, but the observed risk for a 100 mmol/L higher UNa was 0.95 (95% CI 0.82–1.10, p=0.47) (Figure 1). Conclusions While spot measurements of UNa were strongly associated with immediate effects on SBP, the magnitude of within-person variability in UNa precluded detection of associations with SBP several years after baseline or with risk of CVD. The extreme within-person variability in spot UNa may explain the discrepant results of the trials and observational studies of sodium and blood pressure. Figure 1. Spot UNa with SBP and CVD in UK Biobank Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): Core funding from the Medical Research Council-Population Health Research Unit, British Heart Foundation


10.2196/16696 ◽  
2020 ◽  
Vol 8 (8) ◽  
pp. e16696
Author(s):  
Michael P Dorsch ◽  
Maria L Cornellier ◽  
Armella D Poggi ◽  
Feriha Bilgen ◽  
Peiyu Chen ◽  
...  

Background High dietary sodium intake is a significant public health problem in the United States. High sodium consumption is associated with high blood pressure and high risk of cardiovascular disease. Objective The aim of this study was to evaluate the effect of a just-in-time adaptive mobile app intervention, namely, LowSalt4Life, on reducing sodium intake in adults with hypertension. Methods In this study, 50 participants aged ≥18 years who were under treatment for hypertension were randomized (1:1, stratified by gender) into 2 groups, namely, the App group (LowSalt4Life intervention) and the No App group (usual dietary advice) in a single-center, prospective, open-label randomized controlled trial for 8 weeks. The primary endpoint was the change in the 24-hour urinary sodium excretion estimated from spot urine by using the Kawasaki equation, which was analyzed using unpaired two-sided t tests. Secondary outcomes included the change in the sodium intake measured by the food frequency questionnaire (FFQ), the 24-hour urinary sodium excretion, blood pressure levels, and the self-reported confidence in following a low-sodium diet. Results From baseline to week 8, there was a significant reduction in the Kawasaki-estimated 24-hour urinary sodium excretion calculated from spot urine in the App group compared to that in the No App group (–462 [SD 1220] mg vs 381 [SD 1460] mg, respectively; P=.03). The change in the 24-hour urinary sodium excretion was –637 (SD 1524) mg in the App group and –322 (SD 1485) mg in the No App group (P=.47). The changes in the estimated sodium intake as measured by 24-hour dietary recall and by FFQ in the App group were –1537 (SD 2693) mg and –1553 (SD 1764) mg while those in the No App group were –233 (SD 2150) mg and –515 (SD 1081) mg, respectively (P=.07 and P=.01, respectively). The systolic blood pressure change from baseline to week 8 in the App group was –7.5 mmHg while that in the No App group was –0.7 mmHg (P=.12), but the self-confidence in following a low-sodium diet was not significantly different between the 2 groups. Conclusions This study shows that a contextual just-in-time mobile app intervention resulted in a greater reduction in the dietary sodium intake in adults with hypertension than that in the control group over a 8-week period, as measured by the estimated 24-hour urinary sodium excretion from spot urine and FFQ. The intervention group did not show a significant difference from the control group in the self-confidence in following a low sodium diet and in the 24-hour urinary sodium excretion or dietary intake of sodium as measured by the 24-hour dietary recall. A larger clinical trial is warranted to further elucidate the effects of the LowSalt4Life intervention on sodium intake and blood pressure levels in adults with hypertension. Trial Registration ClinicalTrials.gov NCT03099343; https://clinicaltrials.gov/ct2/show/NCT03099343 International Registered Report Identifier (IRRID) RR2-10.2196/11282


2019 ◽  
Author(s):  
Michael P Dorsch ◽  
Maria L Cornellier ◽  
Armella D Poggi ◽  
Feriha Bilgen ◽  
Peiyu Chen ◽  
...  

BACKGROUND High dietary sodium intake is a significant public health problem in the United States. High sodium consumption is associated with high blood pressure and high risk of cardiovascular disease. OBJECTIVE The aim of this study was to evaluate the effect of a just-in-time adaptive mobile app intervention, namely, LowSalt4Life, on reducing sodium intake in adults with hypertension. METHODS In this study, 50 participants aged ≥18 years who were under treatment for hypertension were randomized (1:1, stratified by gender) into 2 groups, namely, the App group (LowSalt4Life intervention) and the No App group (usual dietary advice) in a single-center, prospective, open-label randomized controlled trial for 8 weeks. The primary endpoint was the change in the 24-hour urinary sodium excretion estimated from spot urine by using the Kawasaki equation, which was analyzed using unpaired two-sided <i>t</i> tests. Secondary outcomes included the change in the sodium intake measured by the food frequency questionnaire (FFQ), the 24-hour urinary sodium excretion, blood pressure levels, and the self-reported confidence in following a low-sodium diet. RESULTS From baseline to week 8, there was a significant reduction in the Kawasaki-estimated 24-hour urinary sodium excretion calculated from spot urine in the App group compared to that in the No App group (–462 [SD 1220] mg vs 381 [SD 1460] mg, respectively; <i>P</i>=.03). The change in the 24-hour urinary sodium excretion was –637 (SD 1524) mg in the App group and –322 (SD 1485) mg in the No App group (<i>P</i>=.47). The changes in the estimated sodium intake as measured by 24-hour dietary recall and by FFQ in the App group were –1537 (SD 2693) mg and –1553 (SD 1764) mg while those in the No App group were –233 (SD 2150) mg and –515 (SD 1081) mg, respectively (<i>P</i>=.07 and <i>P</i>=.01, respectively). The systolic blood pressure change from baseline to week 8 in the App group was –7.5 mmHg while that in the No App group was –0.7 mmHg (<i>P</i>=.12), but the self-confidence in following a low-sodium diet was not significantly different between the 2 groups. CONCLUSIONS This study shows that a contextual just-in-time mobile app intervention resulted in a greater reduction in the dietary sodium intake in adults with hypertension than that in the control group over a 8-week period, as measured by the estimated 24-hour urinary sodium excretion from spot urine and FFQ. The intervention group did not show a significant difference from the control group in the self-confidence in following a low sodium diet and in the 24-hour urinary sodium excretion or dietary intake of sodium as measured by the 24-hour dietary recall. A larger clinical trial is warranted to further elucidate the effects of the LowSalt4Life intervention on sodium intake and blood pressure levels in adults with hypertension. CLINICALTRIAL ClinicalTrials.gov NCT03099343; https://clinicaltrials.gov/ct2/show/NCT03099343 INTERNATIONAL REGISTERED REPORT RR2-10.2196/11282


2016 ◽  
Vol 46 (6) ◽  
pp. 766-777 ◽  
Author(s):  
Sonal Dhemla ◽  
Kanika Varma

Purpose There has been a dramatic increase in hypertension in developing countries along with changes in food consumption patterns contributing to higher levels of sodium. Evidence shows that a high level of sodium intake is a major cause of high blood pressure and other heart diseases along with other associated diseases. Therefore, it is important to determine current consumption levels of sodium in a population to facilitate the development and implementation of any specific salt reduction program. Design/methodology/approach The study was conducted among 60 subjects (25-45 years) residing in Jaipur City. Subjects’ sodium consumption levels were assessed via assessment of 24-h urinary sodium excretion levels, the “gold standard” method advocated by WHO/PAHO (2010) and 24-h dietary recall for three days including one holiday. Findings The findings of the study indicated that the subjects were found to be consuming higher levels of sodium (males, 5,792 mg/d; females, 5,911 mg/d) than recommended by WHO, i.e. less than 2,300 mg/d. Completeness of urine was confirmed by fat-free mass determined by electrical bio-impedance (47.6 ± 7.6 kg) and determined by using 24-h urinary excretion of creatinine (33.7 ± 10.1 kg). Two variables were found to be significantly correlated (r = 0.52, p = 0.00). Assuming that the sodium eliminated in the urine comes from the salt only, this excretion would correspond with a dietary salt intake of 14.71 and 15.01 g/d in males and females, respectively. Dietary sodium intake was reported to be 4,133 ± 1,111 mg/day and 3,953 ± 945 mg/d in males and females, respectively. A non-significant difference was found between the two variables. Urinary sodium excretion correlated non-significantly with systolic and diastolic blood pressure figures (r = 0.09 and r = −0.02, respectively). Research limitations/implications The limitations of this study included the small sample size. Purposive sampling was adopted due to difficulty in obtaining urine sample and required willingness of the respondent. This may give fair robust estimate. Originality/value The present results will help provide new data about the baseline salt intake in young and middle-aged population of Jaipur City and will further help the concerned agencies to plan meaningful strategies to reduce salt intake, and it must involve public education and awareness to change the consumption pattern.


Author(s):  
Kaname Tagawa ◽  
Yusuke Tsuru ◽  
Katsumi Yokoi ◽  
Takanori Aonuma ◽  
Junichiro Hashimoto

Abstract Background Central pulse pressure is responsible for the hemodynamics of vital organs, and monitoring this parameter is important for cardiovascular disease prevention. Excess sodium intake and (micro)albuminuria (a manifestation of renal microvascular damage) are known to be strong predictors of cardiovascular disease. We sought to investigate the cross-sectional relationships among dietary sodium intake, albuminuria, and central pulse pressure in a general population cohort. Methods The subjects were 933 apparently healthy adults (mean age, 56 ± 10 years). Radial pressure waveforms were recorded with applanation tonometry to estimate mean arterial pressure, central pulse pressure, forward and backward pressure amplitudes, and augmentation index. The urinary sodium/creatinine and albumin/creatinine ratios were measured in spot urine samples. Results Both the urinary sodium/creatinine and albumin/creatinine ratios were positively correlated with central pulse pressure, even after adjusting for mean arterial pressure (P &lt; 0.001). Moreover, both ratios had a synergistic influence on increasing the central pulse pressure independent of age, sex, estimated glomerular filtration rate, hyperlipidemia, and diabetes (interaction P = 0.04). A similar synergistic influence was found on the forward pressure amplitude, but not on the backward pressure amplitude or augmentation index. The overall results were not altered when the urinary albumin/creatinine ratio was replaced with the existence of chronic kidney disease. Conclusion (Micro)albuminuria strengthens the positive association between urinary sodium excretion and central pulse pressure and systolic forward pressure. Excess sodium intake may magnify the cardiovascular risk by widening the aortic pulsatile pressure, particularly in the presence of concomitant chronic kidney disease.


2021 ◽  
pp. 1-42
Author(s):  
Yi-Jie Wang ◽  
Kuo-Lioug Chien ◽  
Hsiu-Ching Hsu ◽  
Hung-Ju Lin ◽  
Ta-Chen Su ◽  
...  

Abstract Urinary sodium excretion is a potential risk factor for cardiovascular diseases (CVD). However, the underlying biological mechanisms and effects of salt sensitivity are unclear. The purpose of this study was to characterize the relative contribution of biological factors to the sodium-CVD association. A total of 2112 participants were enrolled in this study. Structured questionnaires and blood and urine samples were obtained. Twenty-four-hour sodium excretion was estimated using a single overnight urine sample. Hypertension, metabolic syndrome, and overweight status were considered to indicate salt sensitivity. Cox proportional hazard models were used to investigate the effects of salt sensitivity on urinary sodium excretion and CVD risk. The traditional mediation approach was used to calculate the proportion of mediation. The mean age (standard deviation) of the 2112 participants was 54.5 (12.2) years, and they were followed up for a mean of 14.1 [8.1] years. Compared with those in the lowest quartile, the highest baseline urinary sodium excretion (>4.2g/24 hours) was associated with a 43% higher CVD risk (hazard ratio, 1.43; 95% confidence interval, 1.02-1.99). Participants with high urinary sodium excretion, hypertension, or metabolic syndrome had a significantly high risk of CVD. The carotid intima-media thickness had the largest mediating effect (accounting for 35% of the sodium-CVD association), followed by systolic blood pressure (33%), left ventricular mass (28%), and diastolic blood pressure (14%). Higher urinary sodium excretion increased the risk of CVD, which was explained largely by carotid media-thickness and systolic blood pressure.


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