Editing Ketone bodies (section)

==Ketosis and ketoacidosis==
In normal individuals, there is a constant production of ketone bodies by the liver and their utilization by extrahepatic tissues. The concentration of ketone bodies in blood is maintained around {{nowrap|1 mg/dL}}. Their excretion in urine is very low and undetectable by routine urine tests (Rothera's test).<ref>{{Cite book|url=https://www.ncbi.nlm.nih.gov/books/NBK247/|title=Clinical Methods: The History, Physical, and Laboratory Examinations|last1=Comstock|first1=John P.|last2=Garber|first2=Alan J.|date=1990|publisher=Butterworths|isbn=040990077X|editor-last=Walker|editor-first=H. Kenneth|edition=3rd|location=Boston|pmid=21250091|editor-last2=Hall|editor-first2=W. Dallas|editor-last3=Hurst|editor-first3=J. Willis|access-date=2017-12-19|archive-date=2017-09-10|archive-url=https://web.archive.org/web/20170910175430/https://www.ncbi.nlm.nih.gov/books/NBK247/|url-status=live}}</ref>

When the rate of synthesis of ketone bodies exceeds the rate of utilization, their concentration in blood increases; this is known as ''ketonemia''. This is followed by ''ketonuria'' – excretion of ketone bodies in urine. The overall picture of ketonemia and ketonuria is commonly referred to as ketosis. The smell of acetoacetate and/or acetone in breath is a common feature in ketosis.

When a type 1 diabetic suffers acute biological stress (infection, heart attack, or physical trauma) or fails to administer enough insulin, they may enter the pathological state of [[diabetic ketoacidosis]]. Under these circumstances, the low or absent insulin levels in the blood, combined with the inappropriately high glucagon concentrations,<ref>{{cite journal |last1=Koeslag |first1=J.H. |last2=Saunders |first2=P.T. |last3=Terblanche |first3=E.|title= Topical Review: A reappraisal of blood glucose homeostat which comprehensively explains the type 2 diabetes mellitus/syndrome X complex |journal=Journal of Physiology |volume=549 |issue=Pt 2 |pages=333–46 |doi=10.1113/jphysiol.2002.037895 |pmid=12717005 |pmc=2342944|year=2003 }}</ref> induce the liver to produce glucose at an inappropriately increased rate, causing acetyl-CoA resulting from the beta-oxidation of fatty acids, to be converted into ketone bodies. The resulting very high levels of ketone bodies lower the pH of the blood plasma, which reflexively triggers the kidneys to excrete urine with very high acid levels. The high levels of glucose and ketones in the blood also spill passively into the urine (due to the inability of the renal tubules to reabsorb glucose and ketones from the tubular fluid, being overwhelmed by the high volumes of these substances being filtered into the tubular fluid). The resulting [[osmotic diuresis]] of glucose causes the removal of water and [[electrolyte]]s from the blood resulting in potentially fatal [[dehydration]].

Individuals who follow a low-carbohydrate diet will also develop ketosis. This induced ketosis is sometimes called [[nutritional ketosis]], but the level of ketone body concentrations are on the order of {{nowrap|0.5–5 mM}} whereas the pathological ketoacidosis is {{nowrap|15–25 mM}}.{{Citation needed|date=March 2022}}

The process of ketosis has been studied for its effects in improving the cognitive symptoms of [[neurodegenerative disease]]s including [[Alzheimer's disease]].<ref name="Jensen">{{cite journal |last1=Jensen |first1=NJ |last2=Wodschow |first2=HZ |last3=Nilsson |first3=M |last4=Rungby |first4=J |title=Effects of Ketone Bodies on Brain Metabolism and Function in Neurodegenerative Diseases |journal=International Journal of Molecular Sciences |date=20 November 2020 |volume=21 |issue=22 |page=8767 |doi=10.3390/ijms21228767 |doi-access=free |pmid=33233502|pmc=7699472 }}</ref> Clinical trials have also looked to ketosis in children for [[Angelman syndrome]].<ref>{{Cite web|url = https://clinicaltrials.gov/ct2/show/NCT03644693|title = Evaluation of the Safety and Tolerability of a Nutritional Formulation in Angelman Syndrome|date = 18 August 2020|access-date = 9 February 2022|archive-date = 9 February 2022|archive-url = https://web.archive.org/web/20220209094610/https://clinicaltrials.gov/ct2/show/NCT03644693|url-status = live}}</ref>