Changes

An important aspect of the [[Ketogenic Diet]] is knowing how high the your ketone levels are. {{Skeleton}}* There are three types of [[Ketones]] ; beta-hydroxybutyrate (BOHB)which is measured in the blood, acetone acetoacetate (AcAcAc) which is typically measured in the urine, and acetone which is typically measured in the breath. The easiest and acetoacetate cheapest technique is to measure AcAc in the urine using a test strip. However, this approach is too inaccurate to give more than a vague idea of your ketone levels. Measuring BOHB in the blood is now practical at home using a similar technique to measuring blood glucose, but is far more expensive. Measuring Acetone in the breath is still under development and is not widely available. Currently only blood measurement of BOHB seems to be viable. =Measuring Acetoacetate (AcAc). =* AcAc is typically measured in the urineusing a test strip, such as the [http://www.amazon.com/Multistix-10-100-Test-Strips/dp/B004WNSZGC Multistix] or the cheaper [http://www.amazon.com/Phinex-Parameter-Urinalysis-Reagent-Strips/dp/B0099WTWTA Phinex Multistix equivalent]. These strips check for 10 different things in addition to AcAc, including trace blood, hydration status and urine acidity. (It's important to test for trace blood in your urine if you're on the ketogenic diet to [[Health Risks of the Ketogenic Diet| detect Kidney Stones early]].) ** Easy and This approach is cheap, with the strips costing around $0.20 each. ** Not accurate (semi-quantative) but Unfortunately, urine dipsticks require you to match the color of the test strip against reference patches, so it is not particularly precise. Using image analysis ([[KetoAnalysis]]) helpscan help somewhat. (The test strips use a nitroprusside reagent which changes color from pink to maroon. The addition of hydrogen peroxide does not improve the ability of the urine tests to detect BOHB<ref name="SmithManini2008"/>.)*Worse, there is evidence that the values read from urine dipsticks overestimate the level of ketones in the urine. A study that compared the values from Ketostix with an enzymatic test found the formula "urinary acetoacetate = 0.40(dipstick value) + 0.15" would help correct the overestimation<ref name="Musa-Veloso-2002"/>. [[File:KetoneAcAcUrine.jpg|none|thumb|300px|The level of AcAc in the urine is not accurately measured using dipsticks.]]* Urine To compound matters further, urine levels may do not reflect blood levels of AcAcvery well. ** High level of hydration will dilute urine ketone levels<ref name="Kossoff-2011-2035"/>.** Kidney functioncan change the urine levels<ref name="Laffel-1999"/> as the kidney will reabsorb AcAc<ref name="Galvin-1968"/>. With starvation ketosis, the kidneys increase the reabsorption over time, with one study showing a progression of AcAc reabsorption from 47 (+/-10) mumoles/min on day 3 to 106 (+/-15) on day 10, 89 (+/-10) on day 17 and 96 (+/-10) on day 24<ref name="Sapir-1975"/>. Most studies demonstrate no maximum reabsorption rate<ref name="Wildenhoff-1977"/><ref name="Sapir-1975"/>.*** Time There is also a time delayif the blood levels are changing, this will not be reflected in the urine levels immediately<ref name="Laffel-1999"/>. ** Hydration A study indicated that the level of urine AcAc and blood AcAc vary in a non-linear manner, following the equation "y = 0.3x^0.6 + 0.07" (after correction), but r² was only 0.59 <ref name="Musa-Veloso-2002"/>. [[File:KetoneAcAcUrineBlood.jpg|none|thumb|300px|The levels change measured valuesof AcAc in the blood and urine follow a non-linear relationship.]]*Further problems arise because the levels of AcAc can be quite different to BOHB levels, as shown below. A study of children using the Ketogenic Diet for epilepsy showed that when blood BOHB levels are over 2 mmol/l, urine AcAc dipsticks indicate levels of 80-160 mmol/l<ref name="Gilbert-2000"/>.[[File:KetonesProgressiveStarvation.jpg|none|thumb|300px|Changes in blood ketone levels during progressive starvation<ref name="Cahill2006"/>.]]* False Finally, false positives can occur for a number of reasons. ** Pigmented urine<ref name="patient.co.uk"/> (trace levelonly) from pigmented .** Vitamin C<ref name="sensorhealth.com"/>.** Low urine pH (acidic)<ref name="drsperoni.com"/>.** Increased urine specific gravity<ref name="drsperoni.com"/><ref name="sensorhealth.com"/>.** Phenolphthalein (a laxative used in many preparations under various trade names)<ref name="drsperoni.com"/>.** The amino acid L-dopa<ref name="drsperoni.com"/>.** Drugs, including** False positives from vitamin C* Drugs Levodopa, Bendopa, medicationBrocadopa, etcLarodopa (all used to treat Parkinson's disease)<ref name="drsperoni.com"/><ref name="sensorhealth.com"/>.*** Glucocorticoids<ref name="sensorhealth.com"/>. ** Levels of AcAc can be quite different to Fever or burns<ref name="Medline"/>.=Measuring beta-hydroxybutyrate (BOHB levels)=* BOHB is measured in the bloodusing a small meter. A test strip is placed in the meter and a drop of blood is added. After a few seconds, the meter will indicate the level of Ketones. There are two meters on the market in the US, the [http://www.amazon.com/Nova-Blood-Glucose-Monitoring-System/dp/B0050Z48IU Nova Max] and the [http://www.amazon.com/Precision-Blood-Glucose-Monitoring-System/dp/B000N64MZA Precision Xtra]. ** Slightly painfulThe [http://www.amazon.com/Nova-Max-Plus-Ketone-Strips/dp/B006TIEUS0 ketone test strips for Nova Max] are cheaper (around $27 for 10 strips), but less accurate and there tend to be a high number of 'bad' test strips. ** ExpensiveThe [http://www.amazon.com/Precision-Xtra-Blood-Ketone-Strips/dp/B001EL30TM ketone test strips for the Precision Xtra] are far more expensive (around $58 for 10 strips), but better quality. ** AccurateThe best option I've found is to order the Precision Xtra strips from Canada for $20 for 10 strips. I've ordered from the [http://www.universaldrugstore.com/medications/ketone Ketone Strips from Universal Drugstore] many times and I've been pleased with their service. It takes a couple of weeks for delivery, and shipping is $7. ** Recommend meter You have to draw a drop of blood for this testing, and sourcesI'd recommend the [http://www.amazon.com/dp/B002NPCC1A Owen Mumford Advanced Lancing Device] for $9. It's not much less painful than other lancing devices, but every bit helps. I also use the narrow (33) gauge [http://www.amazon.com/dp/B0000DD8VM BD Ultra-Fine Lancets]. * =Measuring Acetone=Acetone can be measured in the breath** Not readily available – , but the devices are currently at an experimental** Unclear stage and it's not clear what the cost will would be** Overcomes problem . This approach would overcome many of kidney filtration the problems seen with Urine urine AcAc measurement** Some . However, there would still be some delay between blood ketone changes** Levels in the AcAc level and the levels of Acetone , as well as differing levels of AcAc and AcAc can be quite different to BOHB levels.=See Also={{KetoSeeAlsoKetoList}}