Glycosuria is the excretion of glucose into the urine. Ordinarily, urine contains no glucose because the kidneys are able to reabsorb all of the filtered glucose from the tubular fluid back into the bloodstream. Glycosuria is nearly always caused by elevated blood glucose levels, most commonly due to untreated diabetes mellitus. Rarely, glycosuria is due to an intrinsic problem with glucose reabsorption within the kidneys (such as Fanconi syndrome), producing a condition termed renal glycosuria.[1] Glycosuria leads to excessive water loss into the urine with resultant dehydration, a process called osmotic diuresis.
Alimentary glycosuria is a temporary condition, when a high amount of carbohydrate is taken, it is rapidly absorbed in some cases where a part of the stomach is surgically removed, the excessive glucose appears in urine producing glycosuria.
In a patient with glucosuria, diabetes is confirmed by measuring fasting or random plasma glucose and glycated hemoglobin(HbA1c).[2]
Pathophysiology
Blood is filtered by millions of nephrons, the functional units that comprise the kidneys. In each nephron, blood flows from the arteriole into the glomerulus, a tuft of leaky capillaries. The Bowman's capsule surrounds each glomerulus, and collects the filtrate that the glomerulus forms. The filtrate contains waste products (e.g. urea), electrolytes (e.g. sodium, potassium, chloride), amino acids, and glucose. The filtrate passes into the renal tubules of the kidney. In the first part of the renal tubule, the proximal tubule, glucose is reabsorbed from the filtrate, across the tubular epithelium and into the bloodstream. The proximal tubule can only reabsorb a limited amount of glucose (~375 mg/min[3]), known as the transport maximum. When the blood glucose level exceeds about 160–180 mg/dL (8.9-10 mmol/L), the proximal tubule becomes overwhelmed and begins to excrete glucose in the urine.
Approximate correlation between dipstick designation and urine concentration of glucose
This point is called the renal threshold for glucose (RTG).[5] Some people, especially children and pregnant women, may have a low RTG (less than ~7 mmol/L[5] glucose in blood to have glucosuria).
If the RTG is so low that even normal blood glucose levels produce the condition, it is referred to as renal glycosuria.
If yeast is present in the bladder, the sugar in the urine may begin to ferment, producing a rare condition known as urinary auto-brewery syndrome.
References
^Rose, Burton; Rennke, Helmut (1994). Renal pathophysiology – the essentials (1st ed.). Philadelphia: Lippincott Williams & Wilkins. pp. 194. ISBN0-683-07354-0.
^DeFronzo, Ralph A.; Hompesch, Marcus; Kasichayanula, Sreeneeranj; Liu, Xiaoni; Hong, Ying; Pfister, Marc; Morrow, Linda A.; Leslie, Bruce R.; Boulton, David W. (October 2013). "Characterization of Renal Glucose Reabsorption in Response to Dapagliflozin in Healthy Subjects and Subjects With Type 2 Diabetes". Diabetes Care. 36 (10): 3169–3176. doi:10.2337/dc13-0387. ISSN 0149-5992. PMC3781504. PMID 23735727.
^ abcdeHan BR, Oh YS, Ahn KH, Kim HY, Hong SC, Oh MJ, Kim HJ, Kim YT, Lee KW, Kim SH. BR, Han (Sep 2010). "Clinical Implication of 2nd Trimester Glycosuria". Korean J Perinatol. 21 (3): 258–65. [1][2][permanent dead link]
glycosuria, excretion, glucose, into, urine, ordinarily, urine, contains, glucose, because, kidneys, able, reabsorb, filtered, glucose, from, tubular, fluid, back, into, bloodstream, nearly, always, caused, elevated, blood, glucose, levels, most, commonly, unt. Glycosuria is the excretion of glucose into the urine Ordinarily urine contains no glucose because the kidneys are able to reabsorb all of the filtered glucose from the tubular fluid back into the bloodstream Glycosuria is nearly always caused by elevated blood glucose levels most commonly due to untreated diabetes mellitus Rarely glycosuria is due to an intrinsic problem with glucose reabsorption within the kidneys such as Fanconi syndrome producing a condition termed renal glycosuria 1 Glycosuria leads to excessive water loss into the urine with resultant dehydration a process called osmotic diuresis GlycosuriaOther namesGlucosuriaGlucoseSpecialtyEndocrinologyCausesDiabetes dehydrationAlimentary glycosuria is a temporary condition when a high amount of carbohydrate is taken it is rapidly absorbed in some cases where a part of the stomach is surgically removed the excessive glucose appears in urine producing glycosuria Contents 1 Follow up 2 Pathophysiology 3 References 4 External linksFollow up EditIn a patient with glucosuria diabetes is confirmed by measuring fasting or random plasma glucose and glycated hemoglobin HbA1c 2 Pathophysiology EditBlood is filtered by millions of nephrons the functional units that comprise the kidneys In each nephron blood flows from the arteriole into the glomerulus a tuft of leaky capillaries The Bowman s capsule surrounds each glomerulus and collects the filtrate that the glomerulus forms The filtrate contains waste products e g urea electrolytes e g sodium potassium chloride amino acids and glucose The filtrate passes into the renal tubules of the kidney In the first part of the renal tubule the proximal tubule glucose is reabsorbed from the filtrate across the tubular epithelium and into the bloodstream The proximal tubule can only reabsorb a limited amount of glucose 375 mg min 3 known as the transport maximum When the blood glucose level exceeds about 160 180 mg dL 8 9 10 mmol L the proximal tubule becomes overwhelmed and begins to excrete glucose in the urine Approximate correlation between dipstick designation and urine concentration of glucose Urine dipstick designation Approximate urine concentrationtrace 100 mg dL 4 1 250 mg dL 4 df2 500 mg dL 4 3 1000 mg dL 4 4 2000 mg dL 4 This point is called the renal threshold for glucose RTG 5 Some people especially children and pregnant women may have a low RTG less than 7 mmol L 5 glucose in blood to have glucosuria If the RTG is so low that even normal blood glucose levels produce the condition it is referred to as renal glycosuria Glucose in urine can be identified by Benedict s qualitative test If yeast is present in the bladder the sugar in the urine may begin to ferment producing a rare condition known as urinary auto brewery syndrome References Edit Rose Burton Rennke Helmut 1994 Renal pathophysiology the essentials 1st ed Philadelphia Lippincott Williams amp Wilkins pp 194 ISBN 0 683 07354 0 Liman Maria Nataly P Jialal Ishwarlal 2022 03 18 Physiology Glycosuria NCBI Bookshelf PMID 32491373 Retrieved 2022 08 29 DeFronzo Ralph A Hompesch Marcus Kasichayanula Sreeneeranj Liu Xiaoni Hong Ying Pfister Marc Morrow Linda A Leslie Bruce R Boulton David W October 2013 Characterization of Renal Glucose Reabsorption in Response to Dapagliflozin in Healthy Subjects and Subjects With Type 2 Diabetes Diabetes Care 36 10 3169 3176 doi 10 2337 dc13 0387 ISSN 0149 5992 PMC 3781504 PMID 23735727 a b c d e Han BR Oh YS Ahn KH Kim HY Hong SC Oh MJ Kim HJ Kim YT Lee KW Kim SH BR Han Sep 2010 Clinical Implication of 2nd Trimester Glycosuria Korean J Perinatol 21 3 258 65 1 2 permanent dead link a b AIDA on line ExplanationsExternal links Edit Retrieved from https en wikipedia org w index php title Glycosuria amp oldid 1127303520, wikipedia, wiki, book, books, library,
