Assessment of dietary sodium intake using a food frequency questionnaire and 24-hour urinary sodium excretion: a systematic literature review

Introduction: Adherence to the recommended dietary sodium intake is challenging given the ubiquity of sodium in the US food supply. We hypothesized that a multifactorial, behavioral intervention that emphasized spices and herbs would facilitate adherence to dietary sodium recommendations. Methods: SPICE was a two-phase study including adults, 18 years or older, for whom Dietary Guidelines for Americans recommends 1500 mg/d of sodium. In phase one, 55 individuals were fed a low sodium diet for 4 weeks to acclimatize them to eating according to dietary sodium recommendations. Participants were provided all food, snacks and calorie-containing drinks. In phase two, 40 participants from phase 1 were randomized to either a multifactorial behavioral intervention designed to reduce sodium intake (n=20) or a self-directed control group (n=20), for 20 weeks. The intervention included advice on replacing sodium with spices and herbs. The primary study outcome was 24-hour urinary sodium excretion. We used linear regression analyses to determine the effects of the intervention on urinary sodium excretion. Results: Participants were 65% female, 88% African American; 63% had hypertension, 18% had diabetes; mean(sd) age was 61(9.7) years, and BMI was 30(8.9) kg/m 2 . During phase one (controlled feeding), mean 24-hour urinary sodium excretion decreased (150 mmol/d to 72 mmol/d). At the end of the 20-week behavioral intervention, 24-hour urinary sodium excretion increased in both arms but was 42 mmol/d lower in the intervention group than in the control group, p=0.002 (Figure). These findings were robust to methods excluding incomplete urine collections (Mage equation: mean difference -47.4, p=0.001, Joosens equation: mean difference -34.6, p=0.04). Conclusions: A multi-factorial behavioral intervention that emphasizes spices and herbs facilitates adherence to the recommended dietary sodium intake.

Download Full-text

Association between 24-h urinary sodium and potassium excretion and blood pressure among Chinese adults aged 18–69 years

Scientific Reports ◽

10.1038/s41598-021-83049-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Xiaofu Du ◽

Le Fang ◽

Jianwei Xu ◽

Xiangyu Chen ◽

Yamin Bai ◽

...

Keyword(s):

Blood Pressure ◽

Sodium Excretion ◽

Sodium Intake ◽

Urinary Sodium Excretion ◽

Urinary Sodium ◽

Inverse Association ◽

Potassium Excretion ◽

Chinese Adults ◽

Potassium Intake ◽

Sodium And Potassium

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.

Download Full-text

Abstract P403: Seasonal Variation in the Daily Urinary Sodium Excretion in Outpatients From the Northern Japan

Hypertension ◽

10.1161/hyp.70.suppl_1.p403 ◽

2017 ◽

Vol 70 (suppl_1) ◽

Author(s):

Tomoko Hashimoto

Keyword(s):

Seasonal Variation ◽

Sodium Excretion ◽

Salt Intake ◽

Sodium Intake ◽

Urinary Sodium Excretion ◽

Urinary Sodium ◽

Reliable Estimate ◽

Significant Difference ◽

The Mean ◽

Northern Japan

Although the daily urinary sodium excretion (UNaV) is considered to provide the most reliable estimate of the daily sodium intake, it may be affected by salt loss due to sweating in summer. However, theseasonal variation in the daily UNaV associated with a normal lifestyle is unknown. This study was performed in 348 outpatients from the Morioka region during three seasons: summer(summer 1), winter, and the following summer (summer 2). The daily UNaV (g salt/day) was estimated by the second morning urine method three times during each season. Seasonal variation was defined as a significant trend across the three seasons together with a significant difference between winter and both summers. In women, the daily UNaV was higher in winter (11.8±3.0 g salt/day) than in summer 1 (11.2±2.9g salt/day) or summer 2 (11.0±2.9 g salt/day). In contrast, there was no marked seasonal variation in men. An analysis stratified by age (4 quartiles) identified seasonal variation in the older 2 quartiles of women (aged ≧68 years). In these women, the mean seasonal difference in the daily UNaV was 0.9 g of salt/day for both winter vs. summer 1 and winter vs. summer 2, while it was 0.1-0.8 g of salt/day in the other groups. Seasonal variation in the daily UNaV only occurred in older female patients and was relatively small. This is evidence for restricting salt intake throughout the year and should reassure patients who are anxious about salt loss due to sweating in summer.

Download Full-text

Urine Spot Samples Can Be Used to Estimate 24-Hour Urinary Sodium Excretion in Children

Journal of Nutrition ◽

10.1093/jn/nxy211 ◽

2018 ◽

Vol 148 (12) ◽

pp. 1946-1953 ◽

Cited By ~ 6

Author(s):

Magali Rios-Leyvraz ◽

Pascal Bovet ◽

René Tabin ◽

Bernard Genin ◽

Michel Russo ◽

...

Keyword(s):

Sodium Excretion ◽

Salt Intake ◽

Sodium Intake ◽

Population Level ◽

Urinary Sodium Excretion ◽

Cross Sectional Study ◽

Urinary Sodium ◽

Cross Sectional ◽

High Sodium ◽

Individual Level

ABSTRACT Background The gold standard to assess salt intake is 24-h urine collections. Use of a urine spot sample can be a simpler alternative, especially when the goal is to assess sodium intake at the population level. Several equations to estimate 24-h urinary sodium excretion from urine spot samples have been tested in adults, but not in children. Objective The objective of this study was to assess the ability of several equations and urine spot samples to estimate 24-h urinary sodium excretion in children. Methods A cross-sectional study of children between 6 and 16 y of age was conducted. Each child collected one 24-h urine sample and 3 timed urine spot samples, i.e., evening (last void before going to bed), overnight (first void in the morning), and morning (second void in the morning). Eight equations (i.e., Kawasaki, Tanaka, Remer, Mage, Brown with and without potassium, Toft, and Meng) were used to estimate 24-h urinary sodium excretion. The estimates from the different spot samples and equations were compared with the measured excretion through the use of several statistics. Results Among the 101 children recruited, 86 had a complete 24-h urine collection and were included in the analysis (mean age: 10.5 y). The mean measured 24-h urinary sodium excretion was 2.5 g (range: 0.8–6.4 g). The different spot samples and equations provided highly heterogeneous estimates of the 24-h urinary sodium excretion. The overnight spot samples with the Tanaka and Brown equations provided the most accurate estimates (mean bias: −0.20 to −0.12 g; correlation: 0.48–0.53; precision: 69.7–76.5%; sensitivity: 76.9–81.6%; specificity: 66.7%; and misclassification: 23.0–27.7%). The other equations, irrespective of the timing of the spot, provided less accurate estimates. Conclusions Urine spot samples, with selected equations, might provide accurate estimates of the 24-h sodium excretion in children at a population level. At an individual level, they could be used to identify children with high sodium excretion. This study was registered at clinicaltrials.gov as NCT02900261.

Download Full-text

Effects of hypoproteinemia on renal hemodynamics, arterial pressure, and fluid volume

AJP Renal Physiology ◽

10.1152/ajprenal.1987.252.1.f91 ◽

1987 ◽

Vol 252 (1) ◽

pp. F91-F98

Author(s):

R. D. Manning

Keyword(s):

Mean Arterial Pressure ◽

Arterial Pressure ◽

Sodium Excretion ◽

Sodium Intake ◽

Renal Plasma Flow ◽

Urinary Sodium Excretion ◽

Renal Hemodynamics ◽

Fluid Volume ◽

Urinary Sodium ◽

Plasma Aldosterone Concentration

The effects of long-term hypoproteinemia on renal hemodynamics, arterial pressure, and fluid volume were studied in eight conscious dogs over a 34-day period. Plasma protein concentration (PPC) was decreased by daily plasmapheresis, and the effects of decreasing and increasing sodium intake were measured. By the 12th day of plasmapheresis, during which sodium intake was 30 meq/day, PPC had decreased to 2.5 g/dl from a control value of 7.2 g/dl, mean arterial pressure had decreased to 78% of control, glomerular filtration rate (GFR) was 75.2% of control, and urinary sodium excretion was decreased. By day 18 of plasmapheresis, estimated renal plasma flow (ERPF) was decreased to 60% of control due to the decreased arterial pressure and an increase in renal vascular resistance. Also, plasma renin activity and plasma aldosterone concentration were both increased, and the relationship between mean arterial pressure and urinary sodium excretion was distinctly shifted to the left along the arterial pressure axis. In contradistinction to acute experiments, chronic hypoproteinemia results in decreases in GFR, ERPF, and urinary sodium excretion and has marked effects on both fluid volume and arterial pressure regulation.

Download Full-text

Spot urine and 24-h diet recall estimates of dietary sodium intake from the 2008/09 New Zealand Adult Nutrition Survey: a comparison

10.26686/wgtn.12831818 ◽

2020 ◽

Author(s):

RM McLean ◽

SM Williams ◽

Lisa Te Morenga ◽

JI Mann

Keyword(s):

New Zealand ◽

Sodium Excretion ◽

Sodium Intake ◽

Urinary Sodium Excretion ◽

Dietary Sodium ◽

Urine Collection ◽

Limits Of Agreement ◽

Nutrition Survey ◽

Spot Urine ◽

Diet Recall

© 2018, Macmillan Publishers Limited, part of Springer Nature. Background: We aimed to test the difference between estimates of dietary sodium intake using 24-h diet recall and spot urine collection in a large sample of New Zealand adults. Methods: We analysed spot urine results, 24-h diet recall, dietary habits questionnaire and anthropometry from a representative sample of 3312 adults aged 15 years and older who participated in the 2008/09 New Zealand Adult Nutrition Survey. Estimates of adult population sodium intake were derived from 24-h diet recall and spot urine sodium using a formula derived from analysis of INTERSALT data. Correlations, limits of agreement and mean difference were calculated for the total sample, and for population subgroups. Results: Estimated total population 24-h urinary sodium excretion (mean (95% CI)) from spot urine samples was 3035 mg (2990, 3079); 3612 mg (3549, 3674) for men and 2507 mg (2466, 2548) for women. Estimated mean usual daily sodium intake from 24-h diet recall data (excluding salt added at the table) was 2564 mg (2519, 2608); 2849 mg (2779, 2920) for men and 2304 mg (2258, 2350) for women. Correlations between estimates were poor, especially for men, and limits of agreement using Bland–Altman mean difference analysis were wide. Conclusions: There is a poor agreement between estimates of individual sodium intake from spot urine collection and those from 24-hour diet recall. Although, both 24-hour dietary recall and estimated urinary excretion based on spot urine indicate mean population sodium intake is greater than 2 g, significant differences in mean intake by method deserve further investigation in relation to the gold standard, 24-hour urinary sodium excretion.

Download Full-text

24-Hour vs. Spot Urinary Sodium and Potassium Measurements in Adult Hypertensive Patients: A Cohort Validation Study

American Journal of Hypertension ◽

10.1093/ajh/hpz104 ◽

2019 ◽

Vol 32 (10) ◽

pp. 983-991

Author(s):

Elizabeth R Wan ◽

Jennifer Cross ◽

Reecha Sofat ◽

Stephen B Walsh

Keyword(s):

Sodium Excretion ◽

Sodium Intake ◽

Urinary Sodium Excretion ◽

Sodium Concentration ◽

Serum Biochemistry ◽

Urinary Sodium ◽

Hypertensive Patients ◽

Spot Urine ◽

Sodium Ingestion ◽

Weak Negative Correlation

Abstract BACKGROUND Sodium intake is correlated with the development of hypertension. Guyton’s principals suggest that the 24-hour urinary sodium excretion reflects sodium ingestion over the same period. 24-hour urine collections are arduous to collect, so many centers use spot urinary measurements instead. We compared spot to matched 24-hour urinary electrolyte measurements. METHODS We examined 419 hypertensive patients from the UCL Complex Hypertension Clinic. 77 had matched and complete 24-hour and spot urinary and serum biochemistry to examine. We compared the spot and 24-hour urinary; sodium concentration, Na/Cr ratio, FENa, Kawasaki and Tanaka estimated sodium excretion as well as the potassium concentration, K/Cr ratio, Kawasaki and Tanaka potassium excretion. RESULTS Our cohort was 58% male and the median age was 41 years. The 24-hour and spot Na concentrations correlated moderately (r = 0.4633, P < 0.0001). The 24-hour and spot Na/creatinine ratios correlated weakly (r = 0.2625, P = 0.0194). The 24-hour and spot FENa results showed a weak negative correlation (r = −0.222, P = ns). The 24-hour sodium excretion and the Kawasaki-derived spot urine sodium excretion correlated moderately (r = 0.3118, P = 0.0052). All Bland–Altman analyses showed poor agreement. The 24-hour and spot potassium concentrations correlated very poorly (r = 0.1158, P = ns). The 24-hour and spot urinary K/creatinine ratios correlated weakly (r = 0.47, P ≤ 0.0001). 24-hour and Kawasaki and Tanaka estimated potassium excretions correlated much better (r = 0.58, P < 0.0001). CONCLUSIONS Spot urinary measurements of sodium give a very poor understanding of the natriuresis occurring over the same 24-hour period. The Kawasaki and Tanaka estimations of the 24-hour sodium excretion showed a much lower correlation than previously reported.

Download Full-text

Effects of within-person variability in spot urinary sodium measurements on the associations with blood pressure and risk of cardiovascular disease in 0.5 Million adults in UK Biobank

European Heart Journal ◽

10.1093/ehjci/ehaa946.2857 ◽

2020 ◽

Vol 41 (Supplement_2) ◽

Author(s):

J Carter ◽

F Re ◽

I Hammami ◽

T Littlejohns ◽

M Arnold ◽

...

Keyword(s):

Blood Pressure ◽

Cardiovascular Disease ◽

Sodium Excretion ◽

Cox Regression ◽

Sodium Intake ◽

Urinary Sodium Excretion ◽

Urinary Sodium ◽

World Health ◽

Funding Source ◽

Uk Biobank

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

Download Full-text