ArticleClinical and experimental nephrology2011
Validation of the equations for estimating daily sodium excretion from spot urine in patients with chronic kidney disease.
Article in Clinical and experimental nephrology, 2011. The graph could read no effect estimate from its abstract, so it casts no vote on the map. An erratum has been issued. Cited by 22 papers.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
22 citing papers in PubMed, 45 citations in OpenAlex.
- Renal effects of a sodium-glucose cotransporter 2 inhibitor, tofogliflozin, in relation to sodium intake and glycaemic status.Diabetes, obesity & metabolism · 2019Trial
- Spot urine sodium measurements do not accurately estimate dietary sodium intake in chronic kidney disease.The American journal of clinical nutrition · 2016Trial
- Validation of a new self-administered dietary salt intake questionnaire in patients with chronic kidney disease.Hypertension research : official journal of the Japanese Society of Hypertension · 2026Article
- Practical prediction of 24-hour urinary sodium excretion in young people: a new formula derived from Tanaka and INTERSALT formulas.Hypertension research : official journal of the Japanese Society of Hypertension · 2026Article
- Appropriate use of spot-urine sodium estimates for population-level and exploratory analyses: a response to Campbell and Cappuccio.Nutrition & metabolism · 2026Article
- Challenges in improving the equation for estimating 24-h urinary sodium excretion from casual urine in hypertensive patients taking antihypertensive drugs: addressing overestimation, especially at low sodium excretion levels.Hypertension research : official journal of the Japanese Society of Hypertension · 2026Article
- Sodium Intake Estimation in Chronic Kidney Disease: From Measurement Methods to Clinical Outcomes.Turkish journal of nephrology · 2025Article
- Spot urinary sodium in CKD patients: correlation with 24h-excretion and evaluation of commonly used prediction equations.BMC nephrology · 2024Article
- Association between urinary salt excretion and albuminuria in Japanese patients with chronic kidney disease: the Fukuoka kidney disease registry study.Clinical and experimental nephrology · 2021Article
- Estimation of sodium consumption by novel formulas derived from random spot and 12-hour urine collection.PloS one · 2021Article
- Total Body Sodium Balance in Chronic Kidney Disease.International journal of nephrology · 2021Review
- Estimation of Sodium and Potassium Intake: Current Limitations and Future Perspectives.Nutrients · 2020Review
- Risk Reduction for End-Stage Renal Disease by Dietary Guidance Using the Gustatory Threshold Test for Salty Taste.Nutrients · 2020Article
- Estimated 24 h Urinary Sodium-to-Potassium Ratio Is Related to Renal Function Decline: A 6-Year Cohort Study of Japanese Urban Residents.International journal of environmental research and public health · 2020Article
- Estimating the urinary sodium excretion in patients with chronic kidney disease is not useful in monitoring the effects of a low-salt diet.Kidney research and clinical practice · 2018Article
- Article
- Reliable Quantification of the Potential for Equations Based on Spot Urine Samples to Estimate Population Salt Intake: Protocol for a Systematic Review and Meta-Analysis.JMIR research protocols · 2016Article
- Genome-Wide Gene-Sodium Interaction Analyses on Blood Pressure: The Genetic Epidemiology Network of Salt-Sensitivity Study.Hypertension (Dallas, Tex. : 1979) · 2016Article
- Estimation of daily protein intake based on spot urine urea nitrogen concentration in chronic kidney disease patients.Clinical and experimental nephrology · 2016Article
- Effect of One-Week Salt Restriction on Blood Pressure Variability in Hypertensive Patients with Type 2 Diabetes.PloS one · 2016Article
Corrections and comments
- Erratum issued
Authors and funding
13 authors at 2 institutions in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundMeasuring sodium excretion in a 24-h urine collection is the most reliable method of estimating salt intake, but it is not applicable to all patients. As an alternative, equations for estimating Na excretion from Japanese by a spot urine sample were created, but they have not been validated in patients with chronic kidney disease (CKD), which are frequently associated with nocturia and medication.
methodsWe enrolled 136 patients with CKD and collected both 24-h urine and the first morning urine. Na excretion was estimated from the first morning urine by Kawasaki's equation, which was originally used for the second morning urine, and Tanaka's equation, which is applied for spot urine samples taken at any time from 9 am to 7 pm. We evaluated the two equations for bias, RMSE and accuracy within 30 and 50% of the measured Na excretion.
resultsBias, RMSE and accuracy within 30% of the estimated Na excretion were 48 ± 69 and 2 ± 69 mmol/day, 84 and 69 mmol/day, and 35 and 49% using Kawasaki's equation and Tanaka's equation, respectively. Na excretion in the first morning urine was accurately estimated by Tanaka's equation, but it was overestimated by Kawasaki's equation. Nocturia and medication such as diuretics and ACE inhibitor or angiotensin receptor blocker did not affect the accuracy with which Na excretion was estimated by Tanaka's equation substantially.
conclusionTanaka's equation for estimating Na excretion from the first morning urine in patients with CKD is accurate enough for use in clinical practice.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.