+1 Recommend
0 collections
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Validation and Assessment of Three Methods to Estimate 24-h Urinary Sodium Excretion from Spot Urine Samples in High-Risk Elder Patients of Stroke from the Rural Areas of Shaanxi Province

      Read this article at

          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.


          Background: 24-h urine collection is regarded as the “gold standard” for monitoring sodium intake at the population level, but ensuring high quality urine samples is difficult to achieve. The Kawasaki, International Study of Sodium, Potassium, and Blood Pressure (INTERSALT) and Tanaka methods have been used to estimate 24-h urinary sodium excretion from spot urine samples in some countries, but few studies have been performed to compare and validate these methods in the Chinese population. Objective: To compare and validate the Kawasaki, INTERSALT and Tanaka formulas in predicting 24-h urinary sodium excretion using spot urine samples in 365 high-risk elder patients of strokefrom the rural areas of Shaanxi province. Methods: Data were collected from a sub-sample of theSalt Substitute and Stroke Study. 365 high-risk elder patients of stroke from the rural areas of Shaanxi province participated and their spot and 24-h urine specimens were collected. The concentrations of sodium, potassium and creatinine in spot and 24-h urine samples wereanalysed. Estimated 24-h sodium excretion was predicted from spot urine concentration using the Kawasaki, INTERSALT, and Tanaka formulas. Pearson correlation coefficients and agreement by Bland-Altman method were computed for estimated and measured 24-h urinary sodium excretion. Results: The average 24-h urinary sodium excretion was 162.0 mmol/day, which representing a salt intake of 9.5 g/day. Three predictive equations had low correlation with the measured 24-h sodium excretion (r = 0.38, p < 0.01; ICC = 0.38, p < 0.01 for the Kawasaki; r = 0.35, p < 0.01; ICC = 0.31, p < 0.01 for the INTERSALT; r = 0.37, p < 0.01; ICC = 0.34, p < 0.01 for the Tanaka). Significant biases between estimated and measured 24-h sodium excretion were observed (all p < 0.01 for three methods). Among the three methods, the Kawasaki method was the least biased compared with the other two methods (mean bias: 31.90, 95% Cl: 23.84, 39.97). Overestimation occurred when the Kawasaki and Tanaka methods were used while the INTERSALT method underestimated 24-h sodium excretion. Conclusion: The Kawasaki, INTERSALT and Tanaka methods for estimation of 24-h urinary sodium excretion from spot urine specimens were inadequate for the assessment of sodium intake at the population level in high-risk elder patients of stroke from the rural areas of Shaanxi province, although the Kawasaki method was the least biased compared with the other two methods.

          Related collections

          Most cited references 30

          • Record: found
          • Abstract: found
          • Article: not found

          Intersalt: an international study of electrolyte excretion and blood pressure. Results for 24 hour urinary sodium and potassium excretion. Intersalt Cooperative Research Group.

          The relations between 24 hour urinary electrolyte excretion and blood pressure were studied in 10,079 men and women aged 20-59 sampled from 52 centres around the world based on a highly standardised protocol with central training of observers, a central laboratory, and extensive quality control. Relations between electrolyte excretion and blood pressure were studied in individual subjects within each centre and the results of these regression analyses pooled for all 52 centres. Relations between population median electrolyte values and population blood pressure values were also analysed across the 52 centres. Sodium excretion ranged from 0.2 mmol/24 h (Yanomamo Indians, Brazil) to 242 mmol/24 h (north China). In individual subjects (within centres) it was significantly related to blood pressure. Four centres found very low sodium excretion, low blood pressure, and little or no upward slope of blood pressure with age. Across the other 48 centres sodium was significantly related to the slope of blood pressure with age but not to median blood pressure or prevalence of high blood pressure. Potassium excretion was negatively correlated with blood pressure in individual subjects after adjustment for confounding variables. Across centres there was no consistent association. The relation of sodium to potassium ratio to blood pressure followed a pattern similar to that of sodium. Body mass index and heavy alcohol intake had strong, significant independent relations with blood pressure in individual subjects.
            • Record: found
            • Abstract: found
            • Article: not found

            Relative contributions of dietary sodium sources.

            Information on the relative contributions of all dietary sodium (Na) sources is needed to assess the potential efficacy of manipulating the component parts in efforts to implement current recommendations to reduce Na intake in the population. The present study quantified the contributions of inherently food-borne, processing-added, table, cooking, and water sources in 62 adults who were regular users of discretionary salt to allow such an assessment. Seven-day dietary records, potable water collections, and preweighted salt shakers were used to estimate Na intake. Na added during processing contributed 77% of total intake, 11.6% was derived from Na inherent to food, and water was a trivial source. The observed table (6.2%) and cooking (5.1%) values may overestimate the contribution of these sources in the general population due to sample characteristics, yet they were still markedly lower than previously reported values. These findings, coupled with similar observations from other studies, indicate that reduction of discretionary salt will contribute little to moderation of total Na intake in the population.
              • Record: found
              • Abstract: not found
              • Article: not found

              Guideline: Sodium Intake for Adults and Children


                Author and article information

                Int J Environ Res Public Health
                Int J Environ Res Public Health
                International Journal of Environmental Research and Public Health
                11 October 2017
                October 2017
                : 14
                : 10
                [1 ]Xi’an Jiaotong University Health Science Center, School of Public Health, No. 76 West Yanta Road, Xi’an 710061, Shaanxi, China; mawenxia1028@ (W.M.); zhangrj@ (R.Z.); 18792674133@ (F.L.); 18792423075@ (D.Y.); fym0401@ (Y.F.) rongjie5001@ (J.R.)
                [2 ]The George Institute for Global Health at Peking University Health Science Center, No. 6 Zhichun Road Haidian District, Beijing 100088, China; xyin@
                Author notes
                [* ]Correspondence: mtian@ (M.T.); yuyan@ (Y.Y.); Fax: +86-029-826-55111 (Y.Y.)
                © 2017 by the authors.

                Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (


                Public health

                urinary sodium excretion, spot urine, 24-h urine


                Comment on this article