Ketone bodies: acetone, acetoacetic acid, and beta-hydroxybutyric acid
Pronunciation
/kɪˈtoʊsɪs/
Specialty
Endocrinology
Ketosis is a metabolic state characterized by elevated levels of ketone bodies in the blood or urine. Physiological ketosis is a normal response to low glucose availability, such as low-carbohydrate diets or fasting, that provides an additional energy source for the brain in the form of ketones. In physiological ketosis, ketones in the blood are elevated above baseline levels, but the body's acid–base homeostasis is maintained. This contrasts with ketoacidosis, an uncontrolled production of ketones that occurs in pathologic states and causes a metabolic acidosis, which is a medical emergency. Ketoacidosis is most commonly the result of complete insulin deficiency in type 1 diabetes or late-stage type 2 diabetes. Ketone levels can be measured in blood, urine or breath and are generally between 0.5 and 3.0 millimolar (mM) in physiological ketosis, while ketoacidosis may cause blood concentrations greater than 10 mM.[1]
Trace levels of ketones are always present in the blood and increase when blood glucose reserves are low and the liver shifts from primarily metabolizing carbohydrates to metabolizing fatty acids.[2] This occurs during states of increased fatty acid oxidation such as fasting, starvation, carbohydrate restriction, or prolonged exercise. When the liver rapidly metabolizes fatty acids into acetyl-CoA, some acetyl-CoA molecules can then be converted into ketone bodies: pyruvate, acetoacetate, beta-hydroxybutyrate, and acetone.[1][2] These ketone bodies can function as an energy source as well as signalling molecules.[3] The liver itself cannot utilize these molecules for energy, so the ketone bodies are released into the blood for use by peripheral tissues including the brain.[2]
When ketosis is induced by carbohydrate restriction, it is sometimes referred to as nutritional ketosis. A low-carbohydrate, moderate protein diet that can lead to ketosis is called a ketogenic diet. Ketosis is well-established as a treatment for epilepsy and is also effective in treating type 2 diabetes.[4]
^ abCite error: The named reference :6 was invoked but never defined (see the help page).
^ abcWard C (2015). "Ketone Body Metabolism". Diapedia. doi:10.14496/dia.51040851169.29. Archived from the original on 2018-11-11. Retrieved 30 September 2019.[self-published source?]
^Mattson MP, Moehl K, Ghena N, Schmaedick M, Cheng A (2018). "Intermittent metabolic switching, neuroplasticity and brain health". Nature Reviews. Neuroscience. 19 (2): 63–80. doi:10.1038/nrn.2017.156. PMC 5913738. PMID 29321682.
^Westman EC, Tondt J, Maguire E, Yancy WS (15 September 2018). "Implementing a low-carbohydrate, ketogenic diet to manage type 2 diabetes mellitus". Expert Review of Endocrinology & Metabolism. 13 (5): 263–272. doi:10.1080/17446651.2018.1523713. PMID 30289048. S2CID 52920398.
Ketosis is a metabolic state characterized by elevated levels of ketone bodies in the blood or urine. Physiological ketosis is a normal response to low...
uncontrolled production of ketone bodies that cause a metabolic acidosis. While ketosis refers to any elevation of blood ketones, ketoacidosis is a specific pathologic...
generally based on symptoms. An elevated anion gap metabolic acidosis and ketosis is the classic present. However, a mixed acid-base disorder may be present...
during ketosis. On the other hand, most people can smell acetone, whose "sweet & fruity" odor also characterizes the breath of persons in ketosis or, especially...
African-American and Hispanic people. Their condition is then labeled "ketosis-prone type 2 diabetes". Drugs in the gliflozin class (SGLT2 inhibitors)...
vertebrates, including humans. Ketone bodies are elevated in the blood (ketosis) after fasting, including a night of sleep; in both blood and urine in...
Adenosine triphosphate (ATP) is a nucleotide that provides energy to drive and support many processes in living cells, such as muscle contraction, nerve...
refers to any circumstance in which low blood glucose is accompanied by ketosis, the presence of ketone bodies (such as beta-hydroxybutyrate) in the blood...
Other risk factors: Lack of sufficient insulin (but enough to prevent ketosis) Poor kidney function Poor fluid intake (dehydration) Older age (50–70...
due to starvation, ketogenic diets, or prolonged exercise, leading to ketosis. However, with the introduction of exogenous ketone supplements, it is...
form of glucose Avoiding the breakdown of amino acids for energy Avoiding ketosis from the breakdown of fatty acids Cellular and protein recognition Glycoprotein...
source. An elevated level of ketone bodies in the blood (a state called ketosis) eventually lowers the frequency of epileptic seizures. Around half of...
The findings of acetone without acidosis leads to the sine qua non of "ketosis without acidosis." Isopropyl alcohol is oxidized to form acetone by alcohol...
diabetes (including slowly evolving, immune-mediated diabetes of adults and ketosis-prone type 2 diabetes), hyperglycemia first detected during pregnancy,...
including prolonged fasting and high-fat low-carbohydrate dieting, can produce ketosis, in which acetone is formed in body tissue. Certain health conditions,...
glucose absorption (e.g. from inadequate insulin) combined with metabolic ketosis. It can lead to diabetic ketoacidosis, a medical emergency. Acute Happens...
re-oxidized when they transfer electrons to the electron transport chain. Ketosis is a metabolic process where the body prioritizes ketone bodies, produced...
effect of therapeutic hypothermia, specifically during the induction phase. Ketosis – Using body fats as fuel instead of carbohydrates Polydipsia – excessive...
two carbon atoms are released as carbon dioxide during the cycle. During ketosis, however, acetyl-CoA from fatty acids yields ketone bodies, including acetone...
oxidized to form acetone by alcohol dehydrogenase in the liver, leading to ketosis when ingested in large quantities. 1-butanol 1-pentanol (n-amyl alcohol)...
hyperglycemia in gliclazide-responsive diabetes mellitus of stable, mild, non-ketosis prone, type 2 diabetes. It is used when diabetes cannot be controlled by...
Calorimetry: XLV. Prolonged Meat Diets With A Study Of Kidney Function And Ketosis" (PDF). J. Biol. Chem. 87 (3): 651–668. doi:10.1016/S0021-9258(18)76842-7...
development of its smart breath sensor that detects when the body is in ketosis. "Multinationals Venture into Startup Investing". Bloomberg.com. 2011-06-30...
been used in the dairy industry since the 1950s for cows showing signs of ketosis. The negative energy balance during the early stages of lactation can cause...
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