Lactic acidosis is a condition which is associated with lowering of pH of blood and body tissues (i.e. acidosis), which is caused due to accumulation of D-lactate. This condition is distinct from metabolic acidosis, which affects individuals with diabetes.
Cells of the body metabolize glucose to generate energy required to perform the routine functions. The byproducts of this activity are water and carbon-dioxide which are produced via a two-step process, which takes place in the mitochondria. The energy produced is stored in the form of ATP.
Eventually when the cells need energy, the ATP cells are broken down via an ATP hydrolysis (which requires oxygen), to produce protons and energy. Under normal condition, these protons are incorporated back into the ATP which prevents proton build up and maintains neutral pH.
In case of lactic acidosis, inadequate supply of oxygen interferes with the cells ability to synthesize ATP to meet its requirements, which results in glycolysis. As a result excess of pyruvates that are produced are released into the blood stream as lactate which accumulates over a period of time. While glycolysis compensates for shortage of energy, due to lack of ATPs, the protons thus produced cannot bind back to the ATP cells, resulting in a rise of protons causing acidosis.
Some of the common symptoms associated with lactic acidosis include nausea, vomiting, abdominal pain, generalized lethargy, hyperventilation, drop in blood pressure, increased heartbeat, anemia and anxiety.
Causes Of Lactic Acidosis
This condition occurs when body cells receive less than normal oxygen, like during a vigorous exercise. The condition is characterized by presence of lactate >5mmol/L and the serum pH drops to <7.35.
Other causes of lactic acidosis are rare congenital disorders where mitochondrial don’t function adequately. Heavy metal toxicity can also lead to lactic acidosis. Some suggest that lactic acidosis can also result from the deficiency of vitamin B1 or thiamine.
In general lactic acidosis is classified into Type A, which is associated with decreased oxygenation and Type B which is attributed to underlying disease, medication or intoxication or genetic disorder.
Metformin And Lactic Acidosis
Experts suggest that lactic acidosis may be associated with diabetic ketoacidosis, which is associated with use of some forms of anti-diabetic drugs like phenformin. Contrary to clinical belief, metformin doesn’t cause lactic acidosis, though clinicians doubt this claim. Clinicians believe that mitochondrial toxicity caused by the long term use of the drug can trigger lactic acidosis.
Treatment For Lactic Acidosis
The focus of the treatment is to correct the underlying disorder and improving supply of oxygen to the cells. While some have suggested the use of alkaline therapy, there is no evidence about its effectiveness. Further alkaline therapy (bicarbonate infusion) can cause electrolyte disturbances, which can have dreadful effect on the patient’s general health.
This condition cannot be treated at home and often requires hospitalization with ventilator support. In some cases fluid replacement may also be required. The use of antibiotics and chemotherapy may be indicated in cases associated with infection.
A healthy dietary plan which helps overcome nutritional deficiency of vitamin B1 and provides glucose to the body cells is also recommended. Dealing with conditions like severe anemia using iron supplements or dietary iron are also a part of the treatment regimen.