Liver and pancreas
GLDH (glutamaatdehydrogenase)
A liver enzyme from the power plants of liver cells; an addition to ALAT, ASAT and GGT for a specific question.
Everything about this testWhat it measures
GLDH (glutamate dehydrogenase) is an enzyme found mainly in liver cells, in the mitochondria (the power plants of the cell). It only enters the blood when liver cells are more seriously damaged or die, and less so with mild inflammation. GLDH is found mainly in the middle of the liver lobules, the part that suffers first from a lack of oxygen or toxic substances. Muscles contain almost no GLDH.
- Death of liver cells, for example due to a lack of oxygen in the liver, toxic substances or medicines
- A clue as to whether a raised ALAT or ASAT comes from the liver or from the muscles
High
A raised value fits damage to liver cells. A sharp rise is seen mainly with sudden liver damage due to a lack of oxygen (for example with a serious heart problem or shock), toxic substances or an overdose of medicines such as paracetamol. Alcohol, a blocked bile duct and fatty liver can also raise the value. A slightly raised value without symptoms often has a harmless cause. Symptoms that can go with liver damage are tiredness, pain in the upper right abdomen, dark urine and yellow skin or yellow whites of the eyes.
Low
A low or unmeasurable value is normal and has no meaning. Healthy people have little GLDH in their blood.
If your result is abnormal
With a raised value, the GP looks at the other liver values, alcohol, medicines and supplements, and usually has the test repeated after a few weeks. If the liver values stay raised, tests for the cause follow according to the NHG guideline, such as blood tests for hepatitis and an ultrasound of the liver.
Reliability
GLDH adds little to ALAT, ASAT and GGT for the usual question of whether the liver is damaged. The test can help with a specific question, for example whether a raised ASAT or ALAT comes from the liver or from the muscles, or when following sudden liver damage. According to the Dutch GP guideline (NHG), liver testing starts with ALAT, and only a rise that is present on repeat testing is meaningful. For GLDH itself, the meaning in people without symptoms and the cut-off values have been little studied.
Limitations
- Alcohol, medicines (including high-dose paracetamol) and supplements in the days before the blood draw can raise the value.
- A normal GLDH does not rule out liver disease; with mild inflammation or a scarred liver the value can be normal.
- Not every laboratory measures GLDH and reference values differ by method, so results from different laboratories are hard to compare.
How common is this
An abnormal liver value is regularly found in adults who have blood drawn without symptoms. Fatty liver is by far the most common cause. Sudden severe liver damage, in which GLDH rises sharply, is rare.
Who is this useful for
The result is most meaningful with a specific question alongside the usual liver values, for example with a raised ASAT or ALAT after heavy exercise or with a muscle disease, or when following sudden liver damage. If you want to know whether your liver is healthy, ALAT, ASAT, GGT and alkaline phosphatase tell you more. In people without symptoms, a single value says little.
Downsides and risks
- A slightly raised value without symptoms can cause unnecessary worry and unnecessary further tests.
Sources
Always discuss an abnormal result with your GP. If a result is strongly abnormal, we try to reach you as soon as possible. Read your result yourself as well and contact your GP if in doubt. A test does not make a diagnosis. Read more about risks and results