Happy belated Thanksgiving!! While today I probably should be blogging about T is for Tryptophan and Turkey… Unfortunately that has not been at the top of my priority list the past 24+hours….but Lactic Acid has!
Lady A is in the hospital with a bug and had a very high lactic acid reading ( at least very high for her compared to all the others she has had, which we were told were high then)
Have you ever heard of lactic acid before? Probably not… Sound familiar? One hint, it Is not the sugar found in milk… Close, but that is Lactose. But lactic acid was first isolated from milk… As its name implies ( a complete history here)
Lactic Acid ( also known as Lactate or L-lactate) is
A test that measures the amount of lactate in the blood. Lactate is a product of cell metabolism. Depending on pH, it is sometimes present in the form of lactic acid. However, with the neutral pH of the body, most of it will be present in the form of lactate.
Normally, the level of lactate in blood is low. It is produced in excess by muscle cells, red blood cells, brain, and other tissues when there is insufficient oxygen at the cellular level or when the primary way of producing energy in the cells is disrupted.
The principal means of producing energy within cells occurs in the mitochondria, tiny power stations inside most cells of the body. The mitochondria use glucose and oxygen to produce ATP (adenosine triphosphate), the body’s primary source of energy. This is called aerobic energy production.
Whenever cellular oxygen levels decrease and/or the mitochondria are not functioning properly, the body must turn to less efficient energy production (anaerobic energy production) to metabolize glucose and produce ATP. The primary byproduct of this anaerobic process is lactic acid. Lactic acid can accumulate when it is produced faster than the liver can break it down.
When lactic acid levels increase significantly in the blood, the affected person is said to have hyperlactatemia, which can progress to lactic acidosis as more lactic acid accumulates. The body can often compensate for the effects of hyperlactatemia, but lactic acidosis can be severe enough to disrupt a person’s acid/base (pH) balance and cause symptoms such as muscular weakness, rapid breathing, nausea, vomiting, sweating, and even coma. (source)
Measuring lactic acid is not as simple and straightforward as it sounds… Here are some of the things I have learned about this sometimes troublesome biochemical ( especially in regards to mitochondrial disease)…
1) different labs measure lactic acid in different units, making it difficult to compare one draw to the next ESP if done at different labs. Here is a handy
lactic acid units converter . That converts from mg/dL to mmol/L and vice versa, so you can compare apples to apples. Thanks CC!
2) the way in which a lactic acid sample is drawn and processed is very important and can affect the value of the sample.
An elastic band may not be used for a lactic acid test because a band around the arm muscle may cause a false increase in lactic acid.-WebMD
3) crying, struggling or fighting ( for instance a toddler that hates getting their blood drawn or an iv) can elevate a lactate acid reading
I am sure there are many other intricacies to lactic acid that I haven’t mentioned… But my eyes are heavy and sleepy. Hoping for a sound sleep for Lady A and hopes for a discharge to head home tomorrow.
A couple other resources…
Here is an interesting article about lactic acid and 10 (more) things you should know about it!
And here is a story of one family’s fight with (among other things) elevated lactic acid as one of the first warning signs that something metabolic was going on with their sweet little girl.
EDITOR’S Note… Now that we have been discharged (yipee!) and are home sweet home… I thought of a few more resources I wanted to include here…
Lactic Acid (and Glutathione) levels in Patients with Schizophrenia (published in 1934!)
Evaluation and Treatment of Patients with Autism and Mitochondrial Disease by Dr. Richard Kelley (talks about the effects of fasting on lactate and pyruvate measurements).