Acidification is required for calcium and magnesium concentration measurements in equine urine.

Fractional excretion of calcium and magnesium Hydrochloric acid Phosphate

Journal

BMC veterinary research
ISSN: 1746-6148
Titre abrégé: BMC Vet Res
Pays: England
ID NLM: 101249759

Informations de publication

Date de publication:
10 Jan 2024
Historique:
received: 07 02 2023
accepted: 05 12 2023
medline: 11 1 2024
pubmed: 11 1 2024
entrez: 10 1 2024
Statut: epublish

Résumé

Acidification of equine urine to promote dissociation of ion complexes is a common practice for urine ion concentration measurements. The objective of this study was to evaluate the effect of acidification and storage after acidification on calcium (Ca), magnesium (Mg) and phosphate (P) concentrations and on fractional excretion (FE) of these electrolytes. Thirty-two fresh equine urine samples were analysed between December 2016 and July 2020. Complete urinalysis (stick and sediment) was performed on all samples. Ca, Mg, P and creatinine concentrations were measured in supernatant of centrifuged native urine, urine directly centrifuged after acidification and urine centrifuged 1 hour after acidification. Urine was acidified with hydrochloric acid to reach a pH of 1-2. Ca, Mg, P and creatinine concentrations were also measured in blood plasma, and fractional excretion of each electrolyte was calculated. Equality of medians was tested with Friedman tests and Bland-Altman bias plots were used to show the agreement between conditions. Acidification had a statistically significant effect on Ca and Mg concentrations, FE Urine acidification is essential for accurate measurement of Ca and Mg concentrations and therefore FE calculations in equine urine. Storage time of 1 hour after acidification does not significantly change Ca and Mg concentrations.

Sections du résumé

BACKGROUND BACKGROUND
Acidification of equine urine to promote dissociation of ion complexes is a common practice for urine ion concentration measurements. The objective of this study was to evaluate the effect of acidification and storage after acidification on calcium (Ca), magnesium (Mg) and phosphate (P) concentrations and on fractional excretion (FE) of these electrolytes. Thirty-two fresh equine urine samples were analysed between December 2016 and July 2020. Complete urinalysis (stick and sediment) was performed on all samples. Ca, Mg, P and creatinine concentrations were measured in supernatant of centrifuged native urine, urine directly centrifuged after acidification and urine centrifuged 1 hour after acidification. Urine was acidified with hydrochloric acid to reach a pH of 1-2. Ca, Mg, P and creatinine concentrations were also measured in blood plasma, and fractional excretion of each electrolyte was calculated. Equality of medians was tested with Friedman tests and Bland-Altman bias plots were used to show the agreement between conditions.
RESULTS RESULTS
Acidification had a statistically significant effect on Ca and Mg concentrations, FE
CONCLUSIONS CONCLUSIONS
Urine acidification is essential for accurate measurement of Ca and Mg concentrations and therefore FE calculations in equine urine. Storage time of 1 hour after acidification does not significantly change Ca and Mg concentrations.

Identifiants

DOI: 10.1186/s12917-023-03848-1 PMID: 38200552
pubmed: 38200552
doi: 10.1186/s12917-023-03848-1
pii: 10.1186/s12917-023-03848-1
doi:

Types de publication

Journal Article

Langues

eng

Sous-ensembles de citation

IM

Pagination

21

Informations de copyright

© 2024. The Author(s).

Références

McGowan C. Clinical pathology in the racing horse: the role of clinical pathology in assessing fitness and performance in the racehorse. Vet Clin N Am Equine Pract. 2008;24(2):405–21.
doi: 10.1016/j.cveq.2008.03.001
McKenzie EC. 42 - hematology and serum biochemistry of the equine athlete. In: Hinchcliff KW, Kaneps AJ, editors. Equine sports medicine and surgery. 2nd ed. Geor RJ: W.B. Saunders; 2014. p. 921–9.
doi: 10.1016/B978-0-7020-4771-8.00042-9
Avioli LV. Intestinal absorption of calcium. Arch Intern Med. 1972;129(2):345–55.
doi: 10.1001/archinte.1972.00320020189016 pubmed: 4258092
Tryfonidou MA, van den Broek J, van den Brom WE, Hazewinkel HA. Intestinal calcium absorption in growing dogs is influenced by calcium intake and age but not by growth rate. J Nutr. 2002;132(11):3363–8.
doi: 10.1093/jn/132.11.3363 pubmed: 12421852
Hyde ML, Wilkens MR, Fraser DR. In vivo measurement of strontium absorption from the rumen of dairy cows as an index of calcium absorption capacity. J Dairy Sci. 2019;102(6):5699–705.
doi: 10.3168/jds.2018-16052 pubmed: 31005315
Wilkens MR, Marholt L, Eigendorf N, Muscher-Banse AS, Feige K, Schroder B, Breves G, Cehak A. Trans- and paracellular calcium transport along the small and large intestine in horses. Comp Biochem Physiol A Mol Integr Physiol. 2017;204:157–63.
doi: 10.1016/j.cbpa.2016.11.020 pubmed: 27915149
Caple IW, Doake PA, Ellis PG. Assessment of the calcium and phosphorus-nutrition in horses by analysis of urine. Aust Vet J. 1982;58(4):125–31.
doi: 10.1111/j.1751-0813.1982.tb00621.x pubmed: 7126061
Mair TS, Osborn RS. Crystalline composition of equine urinary calculi. Res Vet Sci. 1986;40(3):288–91.
doi: 10.1016/S0034-5288(18)30536-8 pubmed: 3738224
Wood T, Weckman TJ, Henry PA, Chang SL, Blake JW, Tobin T. Equine urine pH: normal population distributions and methods of acidification. Equine Vet J. 1990;22(2):118–21.
doi: 10.1111/j.2042-3306.1990.tb04222.x pubmed: 2318175
King C. Practical use of urinary fractional excretion. J Equine Vet Sci. 1994;14(9):464–8.
doi: 10.1016/S0737-0806(06)81968-4
Gray J, Harris P, Snow DH. Preliminary investigations into the calcium and magnesium status of the horse. Anim Clin Biochem Future. 1988:307–17.
Morris DD, Divers TJ, Whitlock RH. Renal clearance and fractional excretion of electrolytes over a 24-hour period in horses. Am J Vet Res. 1984;45(11):2431–5.
pubmed: 6524740
Harris PA. Preliminary investigations into factors that affect plasma aldosterone concentrations in horses. Res Vet Sci. 1993;54(3):319–28.
doi: 10.1016/0034-5288(93)90129-4 pubmed: 8337480
Harris P, Colles C. The use of creatinine clearance ratios in the prevention of equine rhabdomyolysis: a report of four cases. Equine Vet J. 1988;20(6):459–63.
doi: 10.1111/j.2042-3306.1988.tb01575.x pubmed: 3215174
Coffman J. Percent creatinine clearance ratios. Vet Med Small Anim Clin. 1980;75(4):671–6.
pubmed: 6900459
Ronen N, van Heerden J, van Amstel SR. Clinical and biochemistry findings, and parathyroid hormone concentrations in three horses with secondary hyperparathyroidism. J S Afr Vet Assoc. 1992;63(3):134–6.
pubmed: 1404225
Traver DS, Coffman JR, Moore JN, Salem CA, et al. Urine clearance ratios as a diagnostic aid in equine metabolic disease. Proc Am Assoc Equine Pract. 1976;22:177–83.
Hodgkinson A. Sampling errors in the determination of urine calcium and oxalate: solubility of calcium oxalate in HCl-urine mixtures. Clin Chim Acta. 1981;109(2):239–44.
doi: 10.1016/0009-8981(81)90341-7 pubmed: 7471500
Pratumvinit B, Reesukumal K, Wongkrajang P, Khejonnit V, Klinbua C, Dangneawnoi W. Should acidification of urine be performed before the analysis of calcium, phosphate and magnesium in the presence of crystals? Clin Chim Acta. 2013;426:46–50.
doi: 10.1016/j.cca.2013.08.025 pubmed: 24012827
van Gammeren AJ, van Haperen C, Kuypers AWHM. The effect of acidification and oxalate concentration on urine calcium measurements in EQAS materials and patient samples. Clin Chem Lab Med. 2012;50(2):375–7.
doi: 10.1515/cclm.2011.711
Sodi R, Bailey LB, Glaysher J, Allars L, Roberts NB, Marks EM, Fraser WD. Acidification and urine calcium: is it a preanalytical necessity? Ann Clin Biochem. 2009;46:484–7.
doi: 10.1258/acb.2009.009027 pubmed: 19729500
Sodi R, Godber IM. Effect of refrigeration, centrifugation, acidification, heat treatment and storage on urine calcium, magnesium and phosphate. Clin Chem Lab Med. 2016;54(12):E379–81.
doi: 10.1515/cclm-2016-0064 pubmed: 27155007
Nicar MJ, Hsu MC, Johnson T, Pak CY. The preservation of urine samples for determination of renal stone risk factors. Lab Med. 1987;18(6):382–4.
doi: 10.1093/labmed/18.6.382 pubmed: 11539109
Salek T, Musil P, Psencik M, Palicka V. Post-collection acidification of spot urine sample is not needed before measurement of electrolytes. Biochem Med (Zagreb). 2022;32(2):020702.
doi: 10.11613/BM.2022.020702 pubmed: 35464747 pmcid: 8996324
Walton RM, Cowell RL, Valenciano AC. Equine hematology, cytology, and clinical chemistry. 2nd ed. Hoboken, NJ: Wiley-Blackwell; 2020.
de Moel PJ, van der Helm AWC, van Rijn M, van Dijk JC, van der Meer WGJ. Assessment of calculation methods for calcium carbonate saturation in drinking water for DIN 38404-10 compliance. Drink Water Eng Sci. 2013;6(2):115–24.
doi: 10.5194/dwes-6-115-2013
Baumann JM, Affolter B. From crystalluria to kidney stones, some physicochemical aspects of calcium nephrolithiasis. World J Nephrol. 2014;3(4):256–67.
doi: 10.5527/wjn.v3.i4.256 pubmed: 25374820 pmcid: 4220359
Tiselius HG, Fornander A, Nilsson M. Studies on the crystallization process following addition of calcium phosphate crystals to solutions with a composition corresponding to that in the collecting duct. In: Conference proceedings. 1999.
Espinosa-Ortiz EJ, Eisner BH, Lange D, Gerlach R. Current insights into the mechanisms and management of infection stones. Nat Rev Urol. 2019;16(1):35–53.
doi: 10.1038/s41585-018-0120-z pubmed: 30470787
Coffman J. Clinical chemistry and pathophysiology of horses percent creatinine clearance ratios. Vet Med Small Anim Clin. 1980:671–6.

Auteurs

Sandra Lapsina (S)

Clinical Laboratory, Department for Clinical Diagnostics and Services, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.

Martina Stirn (M)

Clinical Laboratory, Department for Clinical Diagnostics and Services, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.

Regina Hofmann-Lehmann (R)

Clinical Laboratory, Department for Clinical Diagnostics and Services, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.

Angelika Schoster (A)

Clinic for Equine Medicine, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.

Barbara Riond (B)

Clinical Laboratory, Department for Clinical Diagnostics and Services, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland. briond@vetclinics.uzh.ch.

Classifications MeSH