European Journal of Applied Physiology

, Volume 114, Issue 1, pp 85–92 | Cite as

Assessment of extracellular dehydration using saliva osmolality

  • Brett R. Ely
  • Samuel N. Cheuvront
  • Robert W. Kenefick
  • Marissa G. Spitz
  • Kristen R. Heavens
  • Neil P. Walsh
  • Michael N. Sawka
Original Article



When substantial solute losses accompany body water an isotonic hypovolemia (extracellular dehydration) results. The potential for using blood or urine to assess extracellular dehydration is generally poor, but saliva is not a simple ultra-filtrate of plasma and the autonomic regulation of salivary gland function suggests the possibility that saliva osmolality (Sosm) may afford detection of extracellular dehydration via the influence of volume-mediated factors.


This study aimed to evaluate the assessment of extracellular dehydration using Sosm. In addition, two common saliva collection methods and their effects on Sosm were compared.


Blood, urine, and saliva samples were collected in 24 healthy volunteers during paired euhydration and dehydration trials. Furosemide administration and 12 h fluid restriction were used to produce extracellular dehydration. Expectoration and salivette collection methods were compared in a separate group of eight euhydrated volunteers. All comparisons were made using paired t-tests. The diagnostic potential of body fluids was additionally evaluated.


Dehydration (3.1 ± 0.5 % loss of body mass) decreased PV (−0.49 ± 0.12 L; −15.12 ± 3.94 % change), but Sosm changes were marginal (<10 mmol/kg) and weakly correlated with changes in absolute or relative PV losses. Overall diagnostic accuracy was poor (AUC = 0.77–0.78) for all body fluids evaluated. Strong agreement was observed between Sosm methods (Expectoration: 61 ± 10 mmol/kg, Salivette: 61 ± 8 mmol/kg, p > 0.05).


Extracelluar dehydration was not detectable using plasma, urine, or saliva measures. Salivette and expectoration sampling methods produced similar, consistent results for Sosm, suggesting no methodological influence on Sosm.


Hypohydration Hypovolemia Volume depletion Hydration assessment Furosemide 


  1. Adolph EF, Wills JH (1947) Thirst. In: Visscher MB, Bronk DW, Landis EM, Ivy AC (eds) Physiology of Man in the Desert, Interscience, New York, NY, pp 241–253Google Scholar
  2. Armstrong LE (2005) Hydration assessment techniques. Nutr Rev 63:40–54CrossRefGoogle Scholar
  3. Black RE, Morris SS, Bryce J (2003) Where and why are 10 million children dying every year? Lancet 361:2226–2234PubMedCrossRefGoogle Scholar
  4. Caddy B (1984) Saliva as a specimen for drug analysis. In: Baselt RC (ed) Advances in analytical toxicology. Biomedical Publications, Foster City, pp 198–254Google Scholar
  5. Cheuvront SN, Ely BR, Kenefick RW, Sawka MN (2010a) Biological variation and diagnostic accuracy of dehydration assessment markers. Am J Clin Nutr 92:565–573PubMedCrossRefGoogle Scholar
  6. Cheuvront SN, Kenefick RW, Montain SJ, Sawka MN (2010b) Mechanisms of aerobic performance impairment with heat stress and dehydration. J Appl Physiol 109:1989–1995PubMedCrossRefGoogle Scholar
  7. Cheuvront SN, Ely BR, Kenefick RW, Buller MJ, Charkoudian N, Sawka MN (2012) Hydration assessment using the cardiovascular response to standing. Eur J Appl Physiol 112:4081–4089PubMedCrossRefGoogle Scholar
  8. Cheuvront S, Kenefick R, Charkoudian N, Sawka M (2013) Physiologic basis for understanding quantitative dehydration assessment. Am J Clin Nutr 97:455–462PubMedCrossRefGoogle Scholar
  9. Darrow DC (1938) The importance of deficit of sodium and chloride in dehydration. J Pediatr 13:670–677CrossRefGoogle Scholar
  10. Dill DB, Costill DL (1974) Calculation of percentage changes in volumes of blood, plasma, and red cells in dehydration. J Appl Physiol 37:247–248PubMedGoogle Scholar
  11. Ely BR, Cheuvront SN, Kenefick RW, Sawka MN (2011) Limitations of salivary osmolality as a marker of hydration status. Med Sci Sports Exerc 43:1080–1084PubMedCrossRefGoogle Scholar
  12. Fraser CG, Hyltoft PP, Larsen ML (1990) Setting analytical goals for random analytical error in specific clinical monitoring situations. Clin Chem 36:1625–1628PubMedGoogle Scholar
  13. Freund BJ, Young AJ (1996) Environmental influences body fluid balance during exercise: cold exposure. In: Buskirk ER, Puhl SM (eds) Body Fluid Balance: Exercise and Sport. CRC, New York, pp 159–181Google Scholar
  14. Gennari FJ, Kassirer JP (1974) Osmotic diuresis. N Engl J Med 291:714–720PubMedCrossRefGoogle Scholar
  15. Haditsch B, Roessler A, Hinghofer-Szalkay HG (2007) Renal adrenomedullin and high altitude diuresis. Physiol Res 56:779–787PubMedGoogle Scholar
  16. Hagan RD, Diaz FJ, McMurray RG, Horvath SM (1980) Plasma volume changes related to posture and exercise. Proceedings of the Society for Experimental Biology and Medicine 165:155–160Google Scholar
  17. Hanley JA, McNeil BJ (1983) A method of comparing the areas under receiver operating characteristic curves derived from the same cases. Radiology 148:839–843PubMedGoogle Scholar
  18. Hayajneh WA, Jdaitawi H, Al SA, Hayajneh YA (2010) Comparison of clinical associations and laboratory abnormalities in children with moderate and severe dehydration. J Pediatr Gastroenterol Nutr 50:290–294PubMedCrossRefGoogle Scholar
  19. Hoyt RW, Honig A (1996) Body fluid and energy metabolism at high altitude. In: Blatteis CM, Fregley MJ (eds) Handbook of Physiology: Adaptation to the environment, Oxford University Press for the American Physiological Society, New York, pp 1277–1289Google Scholar
  20. Institute of Medicine (2005) Dietary reference intakes for water, potassium, sodium, chloride, and sulfate. Dietary reference intakes for water, potassium, sodium, chloride, and sulfate The National Academies Press, Washington, DCGoogle Scholar
  21. Jackson A, Pollock M (1985) Practical assessment of body composition. Physician Sports Med J 13:75–90Google Scholar
  22. Kimmerly D, Shoemaker J (2003) Hypovolemia and MSNA discharge patterns: assessing and interpreting sympathetic responses. Am J Physiol Heart Circ Physiol 284:H1198–H1204PubMedGoogle Scholar
  23. Laron Z (1957) Skin turgor as a quantitative index of dehydration in children. Pediatrics 19:816–822PubMedGoogle Scholar
  24. Lennquist S (1972) Cold-induced diuresis. A study with special reference to electrolyte excretion, osmolal balance and hormonal changes. Scand J Urol Nephrol 9:1–142PubMedGoogle Scholar
  25. Mange K, Matsuura D, Cizman B, Soto H, Ziyadeh FN, Goldfarb S, Neilson EG (1997) Language guiding therapy: the case of dehydration versus volume depletion. Ann Intern Med 127:848–853PubMedCrossRefGoogle Scholar
  26. Matsuo R, Garrett J, Proctor G, Carpenter G (2000) Reflex secretion of proteins into submandibular saliva in conscious rats, before and after preganglionic sympathectomy. J Physiol 527:175–184PubMedCrossRefGoogle Scholar
  27. McGee S, Abernethy III WB, Simel DL (1999) The rational clinical examination. Is this patient hypovolemic? J Amer Med Assoc 281:1022–1029Google Scholar
  28. Nadal JW, Pedersen S, Maddock WG (1941) A comparison between dehydration from salt loss and from water deprivation. J Clin Invest 20:691–703PubMedCentralPubMedCrossRefGoogle Scholar
  29. Nauntofte B (1992) Regulation of electrolyte and fluid secretion in salivary acinar cells. Am J Physiol 263:G823–G837PubMedGoogle Scholar
  30. Nose H, Mack GW, Shi XR, Nadel ER (1988) Shift in body fluid compartments after dehydration in humans. J Appl Physiol 65:318–324PubMedGoogle Scholar
  31. O’Brien C, Young AJ, Sawka MN (1998) Hypohydration and thermoregulation in cold air. J Appl Physiol 84:185–189PubMedGoogle Scholar
  32. Obuchowski N, Lieber M, Wians F (2004) ROC curves in clinical chemistry: uses, misuses, and possible solutions. Clin Chem 50:1118–1125PubMedCrossRefGoogle Scholar
  33. Oliver SJ, Laing SJ, Wilson S, Bilzon JL, Walsh NP (2008) Saliva indices track hypohydration during 48 h of fluid restriction or combined fluid and energy restriction. Arch Oral Biol 53:975–980PubMedCrossRefGoogle Scholar
  34. Peacock WF, Soto KM (2010) Current techniques of fluid status assessment. Contrib Nephrol 164:128–142Google Scholar
  35. Proctor G, Carpenter G (2007) Regulation of salivary gland function by autonomic nerves. Auton Neurosci 133:3–18PubMedCrossRefGoogle Scholar
  36. Romano G, Bortolotti N, Falleti E, Favret G, Gonano F, Bartoli GE (1999) The influence of furosemide on free water clearance. Panminerva Med 41:103–108PubMedGoogle Scholar
  37. Sawka M, Young A, Pandolf K, Dennis R, Valeri C (1992) Erythrocyte, plasma, and blood volume of healthy young men. Med Sci Sports Exerc 24:447–453PubMedGoogle Scholar
  38. Sawka MN, Burke LM, Eichner ER, Maughan RJ, Montain SJ, Stachenfeld NS (2007) American College of Sports Medicine position stand. Exercise and fluid replacement. Med Sci Sports Exerc 39:377–390PubMedCrossRefGoogle Scholar
  39. Schrier RW (1990) Body fluid volume regulation in health and disease: a unifying hypothesis. Ann Intern Med 113:155–159PubMedCrossRefGoogle Scholar
  40. Seay JF, Ely BR, Kenefick RW, Sauer SG, Cheuvront SN (2013) Hypohydration does not alter standing balance. Mot Control 17:190–202Google Scholar
  41. Smith DL, Shalmiyeva I, Deblois J, Winke M (2012) Use of salivary osmolality to assess dehydration. Prehosp Emerg Care 16:128–135PubMedCrossRefGoogle Scholar
  42. Stachenfeld N, Silva C, Keefe D, Kokoszka C, Nadel E (1999) Effects of oral contraceptives on body fluid regulation. J Appl Physiol 87:1016–1025PubMedGoogle Scholar
  43. Stason WB, Cannon PJ, Heinemann HO, Laragh JH (1966) Furosemide. A clinical evaluation of its diuretic action. Circulation 34:910–920PubMedCrossRefGoogle Scholar
  44. Taylor NA, van den Heuvel AM, Kerry P, McGhee S, Peoples GE, Brown MA, Patterson MJ (2012) Observations on saliva osmolality during progressive dehydration and partial rehydration. Eur J Appl Physiol 112:3227–3237PubMedCrossRefGoogle Scholar
  45. Vokes TJ, Weiss NM, Schreiber J, Gaskill MB, Robertson GL (1988) Osmoregulation of thirst and vasopressin during normal menstrual cycle. Am J Physiol 254:R641–R647PubMedGoogle Scholar
  46. Walsh NP, Laing SJ, Oliver SJ, Montague JC, Walters R, Bilzon JL (2004a) Saliva parameters as potential indices of hydration status during acute dehydration. Med Sci Sports Exerc 36:1535–1542PubMedCrossRefGoogle Scholar
  47. Walsh NP, Montague JC, Callow N, Rowlands AV (2004b) Saliva flow rate, total protein concentration and osmolality as potential markers of whole body hydration status during progressive acute dehydration in humans. Arch Oral Biol 49:149–154PubMedCrossRefGoogle Scholar
  48. Wang Z, Deurenberg P, Wang W, Pietrobelli A, Baumgartner RN, Heymsfield SB (1999) Hydration of fat-free body mass: review and critique of a classic body-composition constant. Am J Clin Nutr 69:833–841PubMedGoogle Scholar
  49. Warren JL, Bacon WE, Harris T, McBean AM, Foley DJ, Phillips C (1994) The burden and outcomes associated with dehydration among US elderly, 1991. Am J Public Health 84:1265–1269PubMedCrossRefGoogle Scholar
  50. World Health Organization (1995) The treatment of diarrhoea: a manual for physicians and other senior health workers. Department of Child and Adolescent Health and Development, Geneva, SwitzerlandGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg (outside the USA) 2013

Authors and Affiliations

  • Brett R. Ely
    • 1
    • 2
  • Samuel N. Cheuvront
    • 1
  • Robert W. Kenefick
    • 1
  • Marissa G. Spitz
    • 1
  • Kristen R. Heavens
    • 1
  • Neil P. Walsh
    • 3
  • Michael N. Sawka
    • 4
  1. 1.Thermal and Mountain Medicine DivisionU.S. Army Research Institute of Environmental MedicineNatickUSA
  2. 2.Department of Human PhysiologyUniversity of OregonEugeneUSA
  3. 3.Extremes Research GroupBangor UniversityBangorUK
  4. 4.School of Applied Physiology, Georgia Institute of TechnologyAtlantaUSA

Personalised recommendations