Abstract
Introduction
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.
Purpose
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.
Methods
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.
Results
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).
Conclusions
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.
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References
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 241–253
Armstrong LE (2005) Hydration assessment techniques. Nutr Rev 63:40–54
Black RE, Morris SS, Bryce J (2003) Where and why are 10 million children dying every year? Lancet 361:2226–2234
Caddy B (1984) Saliva as a specimen for drug analysis. In: Baselt RC (ed) Advances in analytical toxicology. Biomedical Publications, Foster City, pp 198–254
Cheuvront SN, Ely BR, Kenefick RW, Sawka MN (2010a) Biological variation and diagnostic accuracy of dehydration assessment markers. Am J Clin Nutr 92:565–573
Cheuvront SN, Kenefick RW, Montain SJ, Sawka MN (2010b) Mechanisms of aerobic performance impairment with heat stress and dehydration. J Appl Physiol 109:1989–1995
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 112:4081–4089
Cheuvront S, Kenefick R, Charkoudian N, Sawka M (2013) Physiologic basis for understanding quantitative dehydration assessment. Am J Clin Nutr 97:455–462
Darrow DC (1938) The importance of deficit of sodium and chloride in dehydration. J Pediatr 13:670–677
Dill DB, Costill DL (1974) Calculation of percentage changes in volumes of blood, plasma, and red cells in dehydration. J Appl Physiol 37:247–248
Ely BR, Cheuvront SN, Kenefick RW, Sawka MN (2011) Limitations of salivary osmolality as a marker of hydration status. Med Sci Sports Exerc 43:1080–1084
Fraser CG, Hyltoft PP, Larsen ML (1990) Setting analytical goals for random analytical error in specific clinical monitoring situations. Clin Chem 36:1625–1628
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 159–181
Gennari FJ, Kassirer JP (1974) Osmotic diuresis. N Engl J Med 291:714–720
Haditsch B, Roessler A, Hinghofer-Szalkay HG (2007) Renal adrenomedullin and high altitude diuresis. Physiol Res 56:779–787
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 165:155–160
Hanley JA, McNeil BJ (1983) A method of comparing the areas under receiver operating characteristic curves derived from the same cases. Radiology 148:839–843
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 50:290–294
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 1277–1289
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, DC
Jackson A, Pollock M (1985) Practical assessment of body composition. Physician Sports Med J 13:75–90
Kimmerly D, Shoemaker J (2003) Hypovolemia and MSNA discharge patterns: assessing and interpreting sympathetic responses. Am J Physiol Heart Circ Physiol 284:H1198–H1204
Laron Z (1957) Skin turgor as a quantitative index of dehydration in children. Pediatrics 19:816–822
Lennquist S (1972) Cold-induced diuresis. A study with special reference to electrolyte excretion, osmolal balance and hormonal changes. Scand J Urol Nephrol 9:1–142
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 127:848–853
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 527:175–184
McGee S, Abernethy III WB, Simel DL (1999) The rational clinical examination. Is this patient hypovolemic? J Amer Med Assoc 281:1022–1029
Nadal JW, Pedersen S, Maddock WG (1941) A comparison between dehydration from salt loss and from water deprivation. J Clin Invest 20:691–703
Nauntofte B (1992) Regulation of electrolyte and fluid secretion in salivary acinar cells. Am J Physiol 263:G823–G837
Nose H, Mack GW, Shi XR, Nadel ER (1988) Shift in body fluid compartments after dehydration in humans. J Appl Physiol 65:318–324
O’Brien C, Young AJ, Sawka MN (1998) Hypohydration and thermoregulation in cold air. J Appl Physiol 84:185–189
Obuchowski N, Lieber M, Wians F (2004) ROC curves in clinical chemistry: uses, misuses, and possible solutions. Clin Chem 50:1118–1125
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 53:975–980
Peacock WF, Soto KM (2010) Current techniques of fluid status assessment. Contrib Nephrol 164:128–142
Proctor G, Carpenter G (2007) Regulation of salivary gland function by autonomic nerves. Auton Neurosci 133:3–18
Romano G, Bortolotti N, Falleti E, Favret G, Gonano F, Bartoli GE (1999) The influence of furosemide on free water clearance. Panminerva Med 41:103–108
Sawka M, Young A, Pandolf K, Dennis R, Valeri C (1992) Erythrocyte, plasma, and blood volume of healthy young men. Med Sci Sports Exerc 24:447–453
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 39:377–390
Schrier RW (1990) Body fluid volume regulation in health and disease: a unifying hypothesis. Ann Intern Med 113:155–159
Seay JF, Ely BR, Kenefick RW, Sauer SG, Cheuvront SN (2013) Hypohydration does not alter standing balance. Mot Control 17:190–202
Smith DL, Shalmiyeva I, Deblois J, Winke M (2012) Use of salivary osmolality to assess dehydration. Prehosp Emerg Care 16:128–135
Stachenfeld N, Silva C, Keefe D, Kokoszka C, Nadel E (1999) Effects of oral contraceptives on body fluid regulation. J Appl Physiol 87:1016–1025
Stason WB, Cannon PJ, Heinemann HO, Laragh JH (1966) Furosemide. A clinical evaluation of its diuretic action. Circulation 34:910–920
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 112:3227–3237
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–R647
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 36:1535–1542
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 49:149–154
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 69:833–841
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 84:1265–1269
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, Switzerland
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Communicated by George Havenith.
The opinions or assertions contained herein are the private views of the authors and should not be construed as official or reflecting the views of the Army or the Department of Defense.
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Ely, B.R., Cheuvront, S.N., Kenefick, R.W. et al. Assessment of extracellular dehydration using saliva osmolality. Eur J Appl Physiol 114, 85–92 (2014). https://doi.org/10.1007/s00421-013-2747-z
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DOI: https://doi.org/10.1007/s00421-013-2747-z