European Journal of Nutrition

, Volume 56, Issue 3, pp 1149–1156 | Cite as

Elevated urinary Na/K ratio among Lebanese elementary school children is attributable to low K intake

  • Carla El Mallah
  • Karina Merhi
  • Hala Ghattas
  • Dareen Shatila
  • Sirine Francis
  • Sani Hlais
  • Imad Toufeili
  • Omar ObeidEmail author
Original Contribution



To estimate total sodium (Na) and potassium (K) intake using non-fasting morning urine specimens among Lebanese elementary (6–10 year old) schoolchildren.


A national cross-sectional study was conducted. A multistage cluster sampling procedure was used to select a representative sample of 1403 healthy children from the eight districts of Lebanon. Age, anthropometric measurements, and urine samples were collected and analyzed for Na, K, and creatinine (Cr).


The ratios of Na and K to Cr were 23.93 ± 15.54 mM/mM (4.86 ± 3.16 mg/mg) and 11.48 ± 5.82 mM/mM (3.97 ± 2.01 mg/mg), respectively, and showed differences (P value <0.001) between age groups. No differences were found between boys and girls in all the measured Na and K parameters. The estimated mean Na intake was 96.57 ± 61.67 mM/day (2.220 ± 1.418 g/day or 5.69 ± 3.64 g NaCl/day) and exceeded the upper limit of intake in half the children. Estimated K intake was 46.6 ± 23.02 mM/day (1.822 ± 0.900 g/day), and almost all children failed to meet the recommended daily K intake. The high Na/K ratio (2.361 ± 1.67 mM/mM or 1.39 ± 0.98 mg/mg) resulted from a combination of high Na and low K intake but was mostly affected by K intake.


About 50 % of children exceeded the recommended daily upper intake for Na, while the majority was below K adequate intake. This unfavorable Na/K ratio is indicative of potentially negative health effects at later stages in life. Interventions aimed at reducing salt intake and increasing consumption of fruits and vegetables are warranted.


Lebanese children Potassium intake Sodium intake Urinary potassium-to-creatinine ratio Urinary sodium-to-creatinine ratio 



This work was funded by the University Research Board (URB) which had no direct or indirect involvements in this project.

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.

Informed consent

All subjects gave their informed consent prior to their inclusion in the study.

Ethical approval

The study protocol was approved by the Institutional Review Board of the American University of Beirut.

Supplementary material

394_2016_1164_MOESM1_ESM.docx (18 kb)
Supplementary material 1 (DOCX 18 kb)


  1. 1.
    Institute of Medicine (2005) Dietary reference intakes for water, potassium, sodium, chloride, and sulfate. National Academy Press, WashingtonGoogle Scholar
  2. 2.
    Strazzullo P, Leclercq C (2014) Sodium. Adv Nutr Int Rev J 5:188–190CrossRefGoogle Scholar
  3. 3.
    Mattes R, Donnelly D (1991) Relative contributions of dietary sodium sources. J Am Coll Nutr 10:383–393CrossRefGoogle Scholar
  4. 4.
    Alexy U, Cheng G, Libuda L, Hilbig A, Kersting M (2012) 24 h-Sodium excretion and hydration status in children and adolescents-Results of the DONALD Study. Clin Nutr 31:78–84CrossRefGoogle Scholar
  5. 5.
    He F, Marrero N, Macgregor G (2008) Salt and blood pressure in children and adolescents. J Hum Hypertens 22:4–11CrossRefGoogle Scholar
  6. 6.
    Tuomilehto J, Jousilahti P, Rastenyte D, Moltchanov V, Tanskanen A, Pietinen P, Nissinen A (2001) Urinary sodium excretion and cardiovascular mortality in Finland: a prospective study. Lancet 357:848–851CrossRefGoogle Scholar
  7. 7.
    Swift PA, Markandu ND, Sagnella GA, He FJ, MacGregor GA (2005) Modest salt reduction reduces blood pressure and urine protein excretion in black hypertensives a randomized control trial. Hypertension 46:308–312CrossRefGoogle Scholar
  8. 8.
    Amiri M, Kelishadi R (2012) Can salt hypothesis explain the trends of mortality from stroke and stomach cancer in western Europe? Int J Prev Med 3:377Google Scholar
  9. 9.
    Karppanen H, Mervaala E (2006) Sodium intake and hypertension. Prog Cardiovasc Dis 49:59–75CrossRefGoogle Scholar
  10. 10.
    Grimes CA, Riddell LJ, Campbell KJ, Nowson CA (2012) Dietary salt intake assessed by 24 h urinary sodium excretion in Australian schoolchildren aged 5–13 years. Public Health Nutr 16:1789–1795CrossRefGoogle Scholar
  11. 11.
    He FJ, Marrero NM, MacGregor GA (2008) Salt intake is related to soft drink consumption in children and adolescents a link to obesity? Hypertension 51:629–634CrossRefGoogle Scholar
  12. 12.
    Geleijnse JM, Witteman JC, Stijnen T, Kloos MW, Hofman A, Grobbee DE (2007) Sodium and potassium intake and risk of cardiovascular events and all-cause mortality: the Rotterdam Study. Eur J Epidemiol 22:763–770CrossRefGoogle Scholar
  13. 13.
    Geleijnse JM, Grobbee DE, Hofman A (1990) Sodium and potassium intake and blood pressure change in childhood. BMJ 300:899–902CrossRefGoogle Scholar
  14. 14.
    Wold Health Organization (2012) Guideline: potassium intake for adults and children. World Health Organization, SwitzerlandGoogle Scholar
  15. 15.
    Chen X, Wang Y (2008) Tracking of blood pressure from childhood to adulthood a systematic review and meta–regression analysis. Circulation 117:3171–3180CrossRefGoogle Scholar
  16. 16.
    Maldonado-Martin A, García-Matarín L, Gil-Extremera B, Avivar-Oyonarte C, García-Granados ME, Gil-García F, Latorre-Hernández J, Miró-Gutiérrez J, Soria-Bonilla A, Vergara-Martín J, Javier-Martínez MR (2002) Blood pressure and urinary excretion of electrolytes in Spanish schoolchildren. J Hum Hypertens 16:473–478CrossRefGoogle Scholar
  17. 17.
    Rodrigues SL, Baldo MP, Machado RC, Forechi L, Molina Mdel C, Mill JG (2014) High potassium intake blunts the effect of elevated sodium intake on blood pressure levels. J Am Soc Hypertens 8:232–238CrossRefGoogle Scholar
  18. 18.
    Tohme R, Jurjus A, Estephan A (2005) The prevalence of hypertension and its association with other cardiovascular disease risk factors in a representative sample of the Lebanese population. J Hum Hypertens 19:861–868CrossRefGoogle Scholar
  19. 19.
    World Health Organization (2014) Noncommunicable diseases (NCD) country profiles, Lebanon. Retrieved from 20 Feb 2014
  20. 20.
    Elliott P, Brown I (2007) Sodium intakes around the world. World Health Organization, GenevaGoogle Scholar
  21. 21.
    Espeland MA, Kumanyika S, Wilson AC, Reboussin DM, Easter L, Self M, Robertson J, Brown WM, McFarlane M, TONE Cooperative Research Group (2001) Statistical issues in analyzing 24-hour dietary recall and 24-hour urine collection data for sodium and potassium intakes. Am J Epidemiol 153:996–1006CrossRefGoogle Scholar
  22. 22.
    Holbrook JT, Patterson KY, Bodner JE, Douglas LW, Veillon C, Kelsay JL, Mertz W, Smith JC (1984) Sodium and potassium intake and balance in adults consuming self-selected diets. Am J Clin Nutr 40:786–793Google Scholar
  23. 23.
    Tanaka T, Okamura T, Miura K, Kadowaki T, Ueshima H, Nakagawa H, Hashimoto T (2002) A simple method to estimate populational 24-h urinary sodium and potassium excretion using a casual urine specimen. J Hum Hypertens 16:97–103CrossRefGoogle Scholar
  24. 24.
    Kawasaki T, Itoh K, Uezono K, Sasaki H (1993) A simple method for estimating 24 h urinary sodium and potassium excretion from second morning voiding urine specimen in adults. Clin Exp Pharmacol Physiol 20:7–14CrossRefGoogle Scholar
  25. 25.
    Kawamura M, Ohmoto A, Hashimoto T, Yagami F, Owada M, Sugawara T (2012) Second morning urine method is superior to the casual urine method for estimating daily salt intake in patients with hypertension. Hypertens Res 35:611–616CrossRefGoogle Scholar
  26. 26.
    Ghattas H, Francis S, El Mallah C, Shatila D, Merhi K, Hlais S, Zimmermann M, Obeid O (2015) Lebanese children are iodine deficient and urinary sodium and fluoride excretion are weak positive predictors of urinary iodine. Eur J Nutr (in press)Google Scholar
  27. 27.
    Johner S, Boeing H, Thamm M, Remer T (2015) Urinary 24-h creatinine excretion in adults and its use as a simple tool for the estimation of daily urinary analyte excretion from analyte/creatinine ratios in populations. Eur J Clin Nutr 69(12):1336–1343CrossRefGoogle Scholar
  28. 28.
    Remer T, Neubert A, Maser-Gluth C (2002) Anthropometry-based reference values for 24-h urinary creatinine excretion during growth and their use in endocrine and nutritional research. Am J Clin Nutr 75:561–569Google Scholar
  29. 29.
    Manz F, Kehrt R, Lausen B, Merkel A (1999) Urinary calcium excretion in healthy children and adolescents. Pediatr Nephrol 13:894–899CrossRefGoogle Scholar
  30. 30.
    Aburto NJ, Ziolkovska A, Hooper L, Elliott P, Cappuccio FP, Meerpohl JJ (2013) Effect of lower sodium intake on health: systematic review and meta-analyses. BMJ 346:f1326. doi: 10.1136/bmj.f1326 CrossRefGoogle Scholar
  31. 31.
    Powles J, Fahimi S, Micha R, Khatibzadeh S, Shi P, Ezzati M, Engell RE, Lim SS, Danaei G, Mozaffarian D (2013) Global Burden of Diseases Nutrition and Chronic Diseases Expert Group (NutriCoDE). Global, regional and national sodium intakes in 1990 and 2010: a systematic analysis of 24 h urinary sodium excretion and dietary surveys worldwide. BMJ 3:e003733CrossRefGoogle Scholar
  32. 32.
    Aparicio A, Rodríguez-Rodríguez E, Cuadrado-Soto E, Navia B, López-Sobaler A, Ortega R (2015) Estimation of salt intake assessed by urinary excretion of sodium over 24 h in Spanish subjects aged 7–11 years. Eur J Nutr 19:1–8Google Scholar
  33. 33.
    Campanozzi A, Avallone S, Barbato A, Iacone R, Russo O, De Filippo G, D’Angelo G, Pensabene L, Malamisura B, Cecere G, Micillo M, Francavilla R, Tetro A, Lombardi G, Tonelli L, Castellucci G, Ferraro L, Di Biase R, Lezo A, Salvatore S, Paoletti S, Siani A, Galeone D, Strazzullo P, MINISAL-GIRCSI Program Study Group (2015) High sodium and low potassium intake among italian children: relationship with age, body mass and blood pressure. PLoS ONE 10:e0121183CrossRefGoogle Scholar
  34. 34.
    Oliveira AC, Padrão P, Moreira A, Pinto M, Neto M, Santos T, Madureira J, Fernandes Ede O, Graça P, Breda J, Moreira P (2015) Potassium urinary excretion and dietary intake: a cross-sectional analysis in 8–10 year-old children. BMC Pediatr 15:60CrossRefGoogle Scholar
  35. 35.
    Safarinejad MR (2003) Urinary mineral excretion in healthy iranian children. Pediatr Nephrol 18:140–144CrossRefGoogle Scholar
  36. 36.
    Kelishadi R, Gheisari A, Zare N, Farajian S, Shariatinejad K (2013) Salt intake and the association with blood pressure in young Iranian children: first report from the middle East and North Africa. Int J Prev Med 4:475Google Scholar
  37. 37.
    Meneton P, Lafay L, Tard A, Dufour A, Ireland J, Ménard J, Volatier JL (2009) Dietary sources and correlates of sodium and potassium intakes in the French general population. Eur J Clin Nutr 63:1169–1175CrossRefGoogle Scholar
  38. 38.
    Magriplis E, Farajian P, Pounis GD, Risvas G, Panagiotakos DB, Zampelas A (2011) High sodium intake of children through ‘hidden’ food sources and its association with the Mediterranean diet: the GRECO study. J Hypertens 29:1069–1076CrossRefGoogle Scholar
  39. 39.
    Cordain L, Eaton SB, Sebastian A, Mann N, Lindeberg S, Watkins BA, O’Keefe JH, Brand-Miller J (2005) Origins and evolution of the Western diet: health implications for the 21st century. Am J Clin Nutr 81:341–354Google Scholar
  40. 40.
    Fischer PW, Vigneault M, Huang R, Arvaniti K, Roach P (2009) Sodium food sources in the Canadian diet. Appl Physiol Nutr Metab 34:884–892CrossRefGoogle Scholar
  41. 41.
    Ohta Y, Tsuchihashi T, Ueno M, Kajioka T, Onaka U, Tominaga M, Eto K (2004) Relationship between the awareness of salt restriction and the actual salt intake in hypertensive patients. Hypertens Res 27:243–246CrossRefGoogle Scholar
  42. 42.
    Anderson CA, Appel LJ, Okuda N, Brown IJ, Chan Q, Zhao L, Ueshima H, Kesteloot H, Miura K, Curb JD, Yoshita K, Elliott P, Yamamoto ME, Stamler J (2010) Dietary sources of sodium in China, Japan, the United Kingdom, and the United States, women and men aged 40 to 59 years: the INTERMAP study. J Am Diet Assoc 110:736–745CrossRefGoogle Scholar
  43. 43.
    Almedawar MM, Nasreddine L, Olabi A, Hamade H, Awad E, Toufeili I, Arnaout S, Isma’eel HA (2005) Sodium intake reduction efforts in Lebanon. Cardiovasc Diagn Ther 5:178Google Scholar
  44. 44.
    Nasreddine L, Akl C, Al-Shaar L (2014) Consumer knowledge, attitudes and salt-related behavior in the middle-East: the case of Lebanon. Nutrients 6:5079–5102CrossRefGoogle Scholar
  45. 45.
    WHO J, FAO (2003) Diet, nutrition and the prevention of chronic diseases. World Health Organ Tech Rep Ser 916Google Scholar
  46. 46.
    De Santo N, Dilorio B, Capasso G, Russo F, Stamler J, Stamler R, Giordano C (1986) The urinary sodium/potassium ratio in children from southern Italy living in Cimitile: a case for concern. Int J Pediatr Nephrol 8:153–158Google Scholar
  47. 47.
    Kristbjornsdottir OK, Halldorsson TI, Thorsdottir I, Gunnarsdottir I (2012) Association between 24-hour urine sodium and potassium excretion and diet quality in six-year-old children: a cross sectional study. Nutr J 11:94CrossRefGoogle Scholar
  48. 48.
    Kristjansdottir AG, Thorsdottir I, De Bourdeaudhuij I, Due P, Wind M, Klepp K-I (2006) Determinants of fruit and vegetable intake among 11-year-old schoolchildren in a country of traditionally low fruit and vegetable consumption. Int J Behav Nutr Phys Act 3:41CrossRefGoogle Scholar
  49. 49.
    Kristjansdottir AG, Thorsdottir I (2009) Adherence to food-based dietary guidelines and evaluation of nutrient intake in 7-year-old children. Public Health Nutr 12:1999–2008CrossRefGoogle Scholar
  50. 50.
    McGill CR, Fulgoni VL III, DiRienzo D, Huth PJ, Kurilich AC, Miller GD (2008) Contribution of dairy products to dietary potassium intake in the United States population. J Am Coll Nutr 27:44–50CrossRefGoogle Scholar
  51. 51.
    Remer T, Fonteyn N, Alexy U, Berkemeyer S (2006) Longitudinal examination of 24-h urinary iodine excretion in schoolchildren as a sensitive, hydration status–independent research tool for studying iodine status. Am J Clin Nutr 83:639–646Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2016

Authors and Affiliations

  • Carla El Mallah
    • 1
  • Karina Merhi
    • 1
  • Hala Ghattas
    • 2
  • Dareen Shatila
    • 1
  • Sirine Francis
    • 1
  • Sani Hlais
    • 3
  • Imad Toufeili
    • 1
  • Omar Obeid
    • 1
    Email author
  1. 1.Department of Nutrition and Food Science, Faculty of Agricultural and Food SciencesAmerican University of BeirutBeirutLebanon
  2. 2.Faculty of Health SciencesAmerican University of BeirutBeirutLebanon
  3. 3.Faculty of MedicineAmerican University of BeirutBeirutLebanon

Personalised recommendations