{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,12]],"date-time":"2026-01-12T05:15:02Z","timestamp":1768194902051,"version":"3.49.0"},"reference-count":38,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2020,8,5]],"date-time":"2020-08-05T00:00:00Z","timestamp":1596585600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Frederik Paulson chair, Ghent University","award":["Frederik Paulson chair, Ghent University"],"award-info":[{"award-number":["Frederik Paulson chair, Ghent University"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JCM"],"abstract":"<jats:p>Urea is the most abundant and the largest contributing factor for urine osmolality. Urinary urea excretion is highly interrelated with dietary protein intake. Accordingly, an increase of urinary urea excretion due to high protein diet may lead to urea-induced osmotic diuresis. This study aims to explore the association between nocturnal polyuria (NP) and urea. This is a post hoc analysis of a prospective observational study of subjects who completed a renal function profile between October 2011 and February 2015 (n = 170). Each subject underwent a 24 h urine collection, which included 8 urine samples collected at 3 h intervals. Urine volume, osmolality, creatinine, urea and sodium were determined. Urinary urea excretion was used to estimate dietary protein intake. Compared to the control group, subjects with NP exhibited significantly higher nighttime urea and sodium excretion. Estimated evening dietary protein intake was correspondingly significantly higher amongst the NP subgroup. Nighttime diuresis rate was positively associated with age and nighttime free water clearance, creatinine clearance, sodium excretion, and urea excretion in NP subjects. Therefore, increased nocturnal urinary urea excretion may reflect an additional important mediator of nocturia owing to excess nocturnal urine production.<\/jats:p>","DOI":"10.3390\/jcm9082532","type":"journal-article","created":{"date-parts":[[2020,8,5]],"date-time":"2020-08-05T15:13:18Z","timestamp":1596640398000},"page":"2532","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":12,"title":["Could Evening Dietary Protein Intake Play a Role in Nocturnal Polyuria?"],"prefix":"10.3390","volume":"9","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-0244-5375","authenticated-orcid":false,"given":"Upeksha S.","family":"Alwis","sequence":"first","affiliation":[{"name":"Department of Human Structure and Repair, Ghent University, 9000 Ghent, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5702-6792","authenticated-orcid":false,"given":"Joris","family":"Delanghe","sequence":"additional","affiliation":[{"name":"Department of Diagnostic Sciences, Ghent University, 9000 Ghent, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1030-9848","authenticated-orcid":false,"given":"Lien","family":"Dossche","sequence":"additional","affiliation":[{"name":"Department of Internal Medicine and Pediatrics, Ghent University, 9000 Ghent, Belgium"},{"name":"Department of Pediatric Nephrology, Ghent University, 9000 Ghent, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Johan Vande","family":"Walle","sequence":"additional","affiliation":[{"name":"Department of Internal Medicine and Pediatrics, Ghent University, 9000 Ghent, Belgium"},{"name":"Department of Pediatric Nephrology, Ghent University, 9000 Ghent, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"John","family":"Van Camp","sequence":"additional","affiliation":[{"name":"Department of Food Technology, Safety and Health, Ghent University, 9000 Ghent, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5236-0783","authenticated-orcid":false,"given":"Thomas F.","family":"Monaghan","sequence":"additional","affiliation":[{"name":"Department of Urology, SUNY Downstate Health Sciences University, Brooklyn, NY 11203, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Saskia","family":"Roggeman","sequence":"additional","affiliation":[{"name":"Research and Policy Department, Psychiatric Center Sint-Jan-Baptist, 9060 Zelzate, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7173-2039","authenticated-orcid":false,"given":"Karel","family":"Everaert","sequence":"additional","affiliation":[{"name":"Department of Human Structure and Repair, Ghent University, 9000 Ghent, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2020,8,5]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"499","DOI":"10.1002\/nau.23917","article-title":"International Continence Society (ICS) report on the terminology for nocturia and nocturnal lower urinary tract function","volume":"38","author":"Hashim","year":"2019","journal-title":"Neurourol. Urodyn."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"S46","DOI":"10.1002\/nau.23569","article-title":"How can we develop a more clinically useful and robust algorithm for diagnosing and treating nocturia? ICI-RS 2017","volume":"37","author":"Everaert","year":"2018","journal-title":"Neurourol. Urodyn."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1358","DOI":"10.1016\/j.juro.2011.05.083","article-title":"Excessive nocturnal urine production is a major contributing factor to the etiology of nocturia","volume":"186","author":"Weiss","year":"2011","journal-title":"J. Urol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1028","DOI":"10.1016\/j.juro.2013.10.100","article-title":"The association between nocturia and nocturnal polyuria in clinical and epidemiological studies: A systematic review and meta-analyses","volume":"191","author":"Hofmeester","year":"2014","journal-title":"J. Urol."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"283","DOI":"10.1016\/j.eururo.2014.09.003","article-title":"Diagnosing the pathophysiologic mechanisms of nocturnal polyuria","volume":"67","author":"Goessaert","year":"2015","journal-title":"Eur. Urol."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"439","DOI":"10.1093\/ageing\/afz200","article-title":"Phenotyping nocturnal polyuria: Circadian and age-related variations in diuresis rate, free water clearance and sodium clearance","volume":"49","author":"Monaghan","year":"2020","journal-title":"Age Ageing"},{"key":"ref_7","first-page":"47","article-title":"The pathophysiology of monosymptomatic nocturnal enuresis with special emphasis on the circadian rhythm of renal physiology","volume":"7175","author":"Dossche","year":"2016","journal-title":"Eur. J. Pediatr."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"478","DOI":"10.1002\/nau.23939","article-title":"International continence society consensus on the diagnosis and treatment of nocturia","volume":"38","author":"Everaert","year":"2019","journal-title":"Neurourol. Urodyn."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"369","DOI":"10.1007\/s40272-020-00401-7","article-title":"Pediatric pharmacology of desmopressin in children with enuresis: A comprehensive review","volume":"22","author":"Gasthuys","year":"2020","journal-title":"Pediatr. Drugs"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"60","DOI":"10.1016\/j.urology.2017.04.025","article-title":"Dietary sodium restriction reduces nocturnal urine volume and nocturnal polyuria index in renal allograft recipients with nocturnal polyuria","volume":"106","author":"Okumura","year":"2017","journal-title":"Urology"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"927","DOI":"10.1002\/nau.23929","article-title":"Effect of salt intake reduction on nocturia in patients with excessive salt intake","volume":"38","author":"Matsuo","year":"2019","journal-title":"Neurourol. Urodyn."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"633","DOI":"10.1111\/jch.13829","article-title":"Sodium restriction improves nocturia in patients at a cardiology clinic","volume":"22","author":"Monaghan","year":"2020","journal-title":"J. Clin. Hypertens"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"223","DOI":"10.1038\/nrneph.2013.22","article-title":"Vasopressin: A novel target for the prevention and retardation of kidney disease?","volume":"9","author":"Bankir","year":"2013","journal-title":"Nat. Rev. Nephrol."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1702","DOI":"10.1093\/ajcn\/87.6.1702","article-title":"Urea-nitrogen production and salvage are modulated by protein intake in fed humans: Results of an oral stable-isotope-tracer protocol and compartmental modeling","volume":"87","author":"Fouillet","year":"2008","journal-title":"Am. J. Clin. Nutr."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1444","DOI":"10.2215\/CJN.10311013","article-title":"Urea and ammonia metabolism and the control of renal nitrogen excretion","volume":"10","author":"Weiner","year":"2015","journal-title":"Clin. J. Am. Soc. Nephrol."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"F2","DOI":"10.1152\/ajprenal.00614.2014","article-title":"Protein-and diabetes-induced glomerular hyperfiltration: Role of glucagon, vasopressin, and urea","volume":"309","author":"Bankir","year":"2015","journal-title":"Am. J. Physiol.-Ren. Physiol."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"EFSA Panel on Dietetic Products, Nutrition, and Allergies (NDA) (2012). Scientific opinion on dietary reference values for protein. EFSA J., 10, 1\u201366.","DOI":"10.2903\/j.efsa.2012.2557"},{"key":"ref_18","unstructured":"Higgins, C. (2020, May 07). Urea and the Clinical Value of Measuring Blood Urea Concentration. Available online: acutecaretesting.org\/en\/articles\/urea-and-the-clinicalvalue-of-measuring-blood-urea-concentration."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"594","DOI":"10.1152\/jappl.1969.26.5.594","article-title":"Effect of urine flow rate on urea reabsorption in man: Urea as a tubular marker","volume":"26","author":"Goldstein","year":"1969","journal-title":"J. Appl. Physiol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"578","DOI":"10.1038\/ki.1988.36","article-title":"Protein-induced glomerular hyperfiltration: Role of hormonal factors","volume":"33","author":"Krishna","year":"1988","journal-title":"Kidney Int."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"F613","DOI":"10.1152\/ajprenal.1986.250.4.F613","article-title":"Human renal response to a meat meal","volume":"250","author":"Hostetter","year":"1986","journal-title":"Am. J. Physiol.-Ren. Fluid Electrolyte Physiol."},{"key":"ref_22","unstructured":"Floege, J. (2010). Assessment of Renal Function. Comprehensive Clinical Nephrology, Elsevier."},{"key":"ref_23","first-page":"245","article-title":"Evaluation of the \u201cAuto-Stat 6010\u201d automatic osmometer and its comparison with the \u201cDigimatic-Advanced 3DII\u201d manual osmometer","volume":"31","author":"Elorza","year":"1993","journal-title":"Eur. J. Clin. Chem. Clin. Biochem."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1011","DOI":"10.1373\/49.6.1011","article-title":"Re-evaluation of formulas for predicting creatinine clearance in adults and children, using compensated creatinine methods","volume":"49","author":"Wuyts","year":"2003","journal-title":"Clin. Chem."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"1721","DOI":"10.1093\/clinchem\/25.10.1721","article-title":"Chemical inhibition used in a kinetic urease\/glutamate dehydrogenase method for urea in serum","volume":"25","author":"Sampson","year":"1979","journal-title":"Clin. Chem."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"306","DOI":"10.1177\/2211068212472183","article-title":"Cobas 8000 modular analyzer series evaluated under routine-like conditions at 14 sites in Australia, Europe, and the United States","volume":"18","author":"Roth","year":"2013","journal-title":"J. Lab. Autom."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"e12687","DOI":"10.14814\/phy2.12687","article-title":"Effect of increased protein intake on renal acid load and renal hemodynamic responses","volume":"4","author":"Dopheide","year":"2016","journal-title":"Physiol. Rep."},{"key":"ref_28","unstructured":"Bel, S., and Tafforeau, J. (2016). Proteins. Food Consumption Survey 2014\u20132015. Report 4, WIV-ISP."},{"key":"ref_29","unstructured":"Bel, S., and Tafforeau, J. (2016). Sodium. Food Consumption Survey 2014\u20132015. Report 4, WIV-ISP."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"258","DOI":"10.1007\/s10157-015-1164-5","article-title":"Estimation of daily protein intake based on spot urine urea nitrogen concentration in chronic kidney disease patients","volume":"20","author":"Kanno","year":"2016","journal-title":"Clin. Exp. Nephrol."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"382","DOI":"10.1007\/s12072-007-9019-0","article-title":"Estimation of protein intake using urinary urea nitrogen in patients with early-stage liver cirrhosis","volume":"1","author":"Kida","year":"2007","journal-title":"Hepatol. Int."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"1333","DOI":"10.1016\/j.nut.2015.05.004","article-title":"Effect of urine urea nitrogen and protein intake adjusted by using the estimated urine creatinine excretion rate on the antiproteinuric effect of angiotensin II type I receptor blockers","volume":"31","author":"Chin","year":"2015","journal-title":"Nutrition"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"1321","DOI":"10.1111\/j.1532-5415.2000.tb02608.x","article-title":"Nocturnal polyuria in older people: Pathophysiology and clinical implications","volume":"48","author":"Miller","year":"2000","journal-title":"J. Am. Geriatr. Soc."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"909","DOI":"10.2215\/CJN.00320106","article-title":"Age-related increase in plasma urea level and decrease in fractional urea excretion: Clinical application in the syndrome of inappropriate secretion of antidiuretic hormone","volume":"1","author":"Musch","year":"2006","journal-title":"Clin. J. Am. Soc. Nephrol."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"R700","DOI":"10.1152\/ajpregu.00500.2006","article-title":"Sex difference in urine concentration across differing ages, sodium intake, and level of kidney disease","volume":"292","author":"Perucca","year":"2007","journal-title":"Am. J. Physiol. Regul. Integr. Comp. Physiol."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"399","DOI":"10.3945\/an.115.010777","article-title":"Circadian rhythms, metabolism, and chrononutrition in rodents and humans","volume":"7","author":"Johnston","year":"2016","journal-title":"Adv. Nutr."},{"key":"ref_37","doi-asserted-by":"crossref","unstructured":"Kessler, K., and Pivovarova-Ramich, O. (2019). Meal timing, aging, and metabolic health. Int. J. Mol. Sci., 20.","DOI":"10.3390\/ijms20081911"},{"key":"ref_38","doi-asserted-by":"crossref","unstructured":"EFSA Panel on Dietetic Products, Nutrition, and Allergies (NDA) (2010). Scientific Opinion on Dietary reference values for water. EFSA J., 8, 1459.","DOI":"10.2903\/j.efsa.2010.1459"}],"container-title":["Journal of Clinical Medicine"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2077-0383\/9\/8\/2532\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T09:56:56Z","timestamp":1760176616000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2077-0383\/9\/8\/2532"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,8,5]]},"references-count":38,"journal-issue":{"issue":"8","published-online":{"date-parts":[[2020,8]]}},"alternative-id":["jcm9082532"],"URL":"https:\/\/doi.org\/10.3390\/jcm9082532","relation":{},"ISSN":["2077-0383"],"issn-type":[{"value":"2077-0383","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,8,5]]}}}