{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,17]],"date-time":"2026-10-17T20:28:36Z","timestamp":1792268916250,"version":"4.4.0"},"reference-count":23,"publisher":"Ovid Technologies (Wolters Kluwer Health)","issue":"5","content-domain":{"domain":["lww.com","ovid.com"],"crossmark-restriction":true},"short-container-title":["JASN"],"published-print":{"date-parts":[[2021,5]]},"abstract":"<jats:p>\n                    Two papers, one in 1986 and another one in 1988, reported a strong inverse correlation between urinary anion gap (UAG) and urine ammonia excretion (UNH\n                    <jats:sub>4<\/jats:sub>\n                    ) in patients with metabolic acidosis and postulated that UAG could be used as an indirect measure of UNH\n                    <jats:sub>4<\/jats:sub>\n                    . This postulation has persisted until now and is widely accepted. In this review, we discuss factors regulating UAG and examine published evidence to uncover errors in the postulate and the design of the original studies. The essential fact is that, in the steady state, UAG reflects intake of Na, K, and Cl. Discrepancy between intake and urinary output of these electrolytes (\n                    <jats:italic toggle=\"yes\">i.e<\/jats:italic>\n                    ., UAG) indicates selective extrarenal loss of these electrolytes or nonsteady state. UNH\n                    <jats:sub>4<\/jats:sub>\n                    excretion, which depends, in the absence of renal dysfunction, mainly on the daily acid load, has no consistent relationship to UAG either theoretically or in reality. Any correlation between UAG and UNH\n                    <jats:sub>4<\/jats:sub>\n                    , when observed, was a fortuitous correlation and cannot be extrapolated to other situations. Furthermore, the normal value of UAG has greatly increased over the past few decades, mainly due to increases in dietary intake of potassium and widespread use of sodium salts with anions other than chloride as food additives. The higher normal values of UAG must be taken into consideration in interpreting UAG.\n                  <\/jats:p>","DOI":"10.1681\/asn.2020101509","type":"journal-article","created":{"date-parts":[[2021,3,5]],"date-time":"2021-03-05T14:41:28Z","timestamp":1614955288000},"page":"1025-1028","update-policy":"https:\/\/doi.org\/10.1097\/lww.0000000000001000","source":"Crossref","is-referenced-by-count":29,"title":["The Urine Anion Gap: Common Misconceptions"],"prefix":"10.1681","volume":"32","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-9826-1134","authenticated-orcid":false,"given":"Jaime","family":"Uribarri","sequence":"first","affiliation":[{"name":"Renal Division, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Man S.","family":"Oh","sequence":"additional","affiliation":[{"name":"Renal Division, Department of Medicine, State University of New York at Downstate, Brooklyn, New York"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"276","published-online":{"date-parts":[[2021,5,3]]},"reference":[{"key":"B1-20240826","doi-asserted-by":"crossref","first-page":"198","DOI":"10.1097\/00000441-198610000-00003","article-title":"The urine anion gap: A clinically useful index of ammonium excretion","volume":"292","author":"Goldstein","year":"1986","journal-title":"Am J Med Sci"},{"key":"B2-20240826","doi-asserted-by":"crossref","first-page":"594","DOI":"10.1056\/NEJM198803103181002","article-title":"The use of the urinary anion gap in the diagnosis of hyperchloremic metabolic acidosis","volume":"318","author":"Batlle","year":"1988","journal-title":"N Engl J Med"},{"key":"B5-20240826","doi-asserted-by":"crossref","first-page":"180","DOI":"10.1159\/000185842","article-title":"Is the urine anion gap a reliable index of urine ammonium excretion in most situations?","volume":"54","author":"Inase","year":"1990","journal-title":"Nephron"},{"key":"B6-20240826","doi-asserted-by":"crossref","first-page":"597","DOI":"10.1016\/S0022-2143(99)90190-7","article-title":"Urine electrolytes and the urine anion and osmolar gaps","volume":"133","author":"Kirschbaum","year":"1999","journal-title":"J Lab Clin Med"},{"key":"B7-20240826","doi-asserted-by":"crossref","first-page":"252","DOI":"10.1159\/000049059","article-title":"Value and determinants of urine anion gap","volume":"90","author":"Oh","year":"2002","journal-title":"Nephron"},{"key":"B8-20240826","doi-asserted-by":"crossref","first-page":"915","DOI":"10.1038\/ki.1989.280","article-title":"A new method for estimating G-I absorption of alkali","volume":"36","author":"Oh","year":"1989","journal-title":"Kidney Int"},{"key":"B9-20240826","doi-asserted-by":"crossref","first-page":"759","DOI":"10.1038\/ki.2013.367","article-title":"Spooky sodium balance","volume":"85","author":"Titze","year":"2014","journal-title":"Kidney Int"},{"key":"B10-20240826","first-page":"207","article-title":"An extravenal mechanism for the maintenance of potassium balance in severe chronic renal failure","volume":"80","author":"Hayes","year":"1967","journal-title":"Trans Assoc Am Physicians"},{"key":"B11-20240826","doi-asserted-by":"crossref","first-page":"247","DOI":"10.1042\/cs0730247","article-title":"Evidence for large intestinal control of potassium homoeostasis in uraemic patients undergoing long-term dialysis","volume":"73","author":"Sandle","year":"1987","journal-title":"Clin Sci (Lond)"},{"key":"B12-20240826","doi-asserted-by":"crossref","first-page":"548","DOI":"10.1016\/0016-5085(94)90184-8","article-title":"Pathophysiology of potassium absorption and secretion by the human intestine","volume":"107","author":"Agarwal","year":"1994","journal-title":"Gastroenterology"},{"key":"B13-20240826","doi-asserted-by":"crossref","first-page":"195","DOI":"10.2215\/CJN.13791217","article-title":"The urine anion gap in context","volume":"13","author":"Batlle","year":"2018","journal-title":"Clin J Am Soc Nephrol"},{"key":"B15-20240826","doi-asserted-by":"crossref","first-page":"494","DOI":"10.1161\/01.HYP.4.4.494","article-title":"Overnight urine collections to estimate sodium intake","volume":"4","author":"Luft","year":"1982","journal-title":"Hypertension"},{"key":"B16-20240826","doi-asserted-by":"crossref","first-page":"1209","DOI":"10.1001\/jama.2018.1156","article-title":"Estimated 24-hour urinary sodium and potassium excretion in US adults","volume":"319","author":"Cogswell","year":"2018","journal-title":"JAMA"},{"key":"B17-20240826","doi-asserted-by":"crossref","first-page":"579","DOI":"10.1016\/j.juro.2010.03.129","article-title":"Adequacy of a single 24-hour urine collection for metabolic evaluation of recurrent nephrolithiasis","volume":"184","author":"Castle","year":"2010","journal-title":"J Urol"},{"key":"B18-20240826","doi-asserted-by":"crossref","first-page":"e0228490","DOI":"10.1371\/journal.pone.0228490","article-title":"Separating the effects of 24-hour urinary chloride and sodium excretion on blood pressure and risk of hypertension: Results from PREVEND","volume":"15","author":"van der Leeuw","year":"2020","journal-title":"PLoS One"},{"key":"B19-20240826","doi-asserted-by":"crossref","first-page":"1029","DOI":"10.1093\/ije\/dyw319","article-title":"Fruit and vegetable intake and the risk of cardiovascular disease, total cancer and all-cause mortality-a systematic review and dose-response meta-analysis of prospective studies","volume":"46","author":"Aune","year":"2017","journal-title":"Int J Epidemiol"},{"key":"B20-20240826","doi-asserted-by":"crossref","first-page":"150","DOI":"10.1053\/j.ackd.2012.10.008","article-title":"Sodium- and phosphorus-based food additives: Persistent but surmountable hurdles in the management of nutrition in chronic kidney disease","volume":"20","author":"Guti\u00e9rrez","year":"2013","journal-title":"Adv Chronic Kidney Dis"},{"key":"B21-20240826","doi-asserted-by":"crossref","first-page":"359","DOI":"10.1159\/000168150","article-title":"A modification of the urine osmolal gap: An improved method for estimating urine ammonium","volume":"10","author":"Dyck","year":"1990","journal-title":"Am J Nephrol"},{"key":"B22-20240826","doi-asserted-by":"crossref","first-page":"205","DOI":"10.2215\/CJN.03770417","article-title":"Urine anion gap to predict urine ammonium and related outcomes in kidney disease","volume":"13","author":"Raphael","year":"2018","journal-title":"Clin J Am Soc Nephrol"},{"key":"B23-20240826","doi-asserted-by":"crossref","first-page":"2215","DOI":"10.1172\/JCI104001","article-title":"The relation of sulfur metabolism to acid-base balance and electrolyte excretion: The effects of DL-methionine in normal man","volume":"38","author":"Lemann","year":"1959","journal-title":"J Clin Invest"},{"key":"B24-20240826","doi-asserted-by":"crossref","first-page":"310","DOI":"10.2337\/diab.30.4.310","article-title":"The mechanism of hyperchloremic acidosis during the recovery phase of diabetic ketoacidosis","volume":"30","author":"Oh","year":"1981","journal-title":"Diabetes"},{"key":"B25-20240826","doi-asserted-by":"crossref","first-page":"1223","DOI":"10.1172\/JCI104353","article-title":"Effects of chronic hypercapnia on electrolyte and acid-base equilibrium. I. Adaptation","volume":"40","author":"Polak","year":"1961","journal-title":"J Clin Invest"},{"key":"B26-20240826","doi-asserted-by":"crossref","first-page":"1243","DOI":"10.1016\/j.kint.2016.12.017","article-title":"The genetic and clinical spectrum of a large cohort of patients with distal renal tubular acidosis","volume":"91","author":"Palazzo","year":"2017","journal-title":"Kidney Int"}],"container-title":["Journal of the American Society of Nephrology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.ovid.com\/10.1681\/ASN.2020101509","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,8,7]],"date-time":"2026-08-07T19:24:42Z","timestamp":1786130682000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.ovid.com\/10.1681\/ASN.2020101509"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,5]]},"references-count":23,"journal-issue":{"issue":"5","published-print":{"date-parts":[[2021]]}},"URL":"https:\/\/doi.org\/10.1681\/asn.2020101509","relation":{},"ISSN":["1046-6673","1533-3450"],"issn-type":[{"value":"1046-6673","type":"print"},{"value":"1533-3450","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,5]]}}}