Can Heart Problems Cause Elevated Liver Enzymes?

The way in which the human body works means that sometimes if something goes wrong in one place, it can have an effect elsewhere. Research has shown that heart disease can have effects on the liver. Elevated liver enzymes occur when there are signs of liver disease and damage. This suggests that liver enzymes may increase due to heart problems. 

This article aims to explore this link and how it occurs.

What are liver enzymes?

What does the Liver do?

Located in the abdominal cavity, the liver itself is an extremely important organ involved in many processes, making it vital for function:

• Breaking down and clearance of drugs and toxic chemicals
• Converting poisonous ammonia into urea
• Maintenance of blood glucose levels (converting excess glucose into glycogen or vice versa when blood glucose is low)
• Production of bile
• Helping blood clot
• Clearance of bilirubin (​​Bilirubin is a yellowish product made by the breakdown of old red blood cells. A healthy liver clears the majority of bilirubin from the body)

As well as the production of many products for the maintenance and regulation of blood plasma. The word ‘hepatic’ means relating to the liver.¹

These many roles signify the importance of the liver, and all of these processes involve the use of enzymes. 

What are enzymes?

By definition, enzymes are proteins that act as a catalyst and speed up a biochemical reaction. They are specific to their reaction and are not used up within it. They are found in many processes within our body, making them extremely useful.

Liver enzymes

The enzymes that are found in the liver are involved in the processes conducted by the liver, as mentioned above. 

Liver enzymes can be a good indication of disease and injury: when the liver is injured, the enzymes are released into the blood. Elevated levels of liver enzymes also indicate liver disease.

Some commonly known liver enzymes are:

ALT (Alanine transaminase)

AST (Aspartate transaminase)

ALP (Alkaline phosphatase)

GGT (Gamma-glutamyltransferase)

Symptoms of elevated liver enzymes

The vast majority of people with elevated liver enzymes will remain asymptomatic. However, individuals with elevated liver enzymes as a result of liver damage are likely to experience symptoms:

• Abdominal pain
• Dark urine (caused by bilirubin in the urine)
• Fatigue
• Itching
• Jaundice (yellowing of the eyes and skin, caused by bilirubin in the bloodstream)
• Light coloured stools
• Loss of appetite
• Nausea and/or vomiting²

Causes of elevated liver enzymes

There are many causes for elevated liver enzymes, of which, some are more common than others…

Statins

Statins are a type of medication used to lower cholesterol levels. A common side effect of these drugs is adverse effects on the liver; the risk of serious liver injury is thought to be very low.

Fatty liver disease

Fatty liver disease indicates a  buildup of fat in the liver. The liver contains a small amount of fat, but it becomes problematic when there is too much. This is often categorised into alcoholic and non-alcoholic fatty liver disease. 

Non-alcoholic fatty liver disease is associated with being overweight or obese . For the majority of people, it doesn’t progress past its first stage. This is where there is an increase of fat in liver cells, usually going undetected. The first stage doesn’t cause harm, but has the potential to progress into serious liver damage if not tested. In its early stages, it lacks symptoms.³

Alcoholic fatty liver disease 

Given its name, alcoholic fatty liver disease is caused by drinking copious amounts of alcohol, causing a build-up of fat in the liver cells. 

Much like its non-alcoholic version, it is extremely rare to have symptoms. Although, heavy drinking constantly can be an indicator.⁴

Haemochromatosis

This genetic condition involves the build-up of iron levels in the body. Too much iron is absorbed from the food and is stored in some organs including the liver. 

Symptoms for hemochromatosis  tend to begin between 30 and 60, causing fatigue, weight loss, weakness, joint pain, erectile dysfunction, and amenorrhea⁵

Hepatitis

The word hepatitis refers to inflammation of the liver. There are many different types of hepatitis, each with different causes. Short-term hepatitis tends to not exhibit symptoms, however, it is still possible. Long-term hepatitis also tends to not have symptoms, until the liver is unable to function properly (liver failure may have begun). 

Hepatitis A

This variation has viral causes, and is often transmitted through  food or water that has been contaminated by an infected person. It is more prominent  in countries with poor sanitation. However, it usually passes  within a few months, which poses as non  life-threatening.

Hepatitis B

Also caused by a virus, hepatitis B is spread via the blood of an infected individual. This usually means transmission through an infected pregnant woman to its child. Occasionally it can spread via unprotected sex or by sharing needles. It is more common in southeast Asia and sub-Saharan Africa. If contracted as an adult, the virus tends to clear up within a couple of months. If contracted as a child, it becomes a long-term condition. 

Hepatitis C

This is the most common type of viral hepatitis in the UK. Much like hepatitis C, it is spread through infected blood; the most common route of transmission is sharing needles. It often causes flu-like or no symptoms. Approximately 25% of patients will recover, whilst the remaining 75% will develop chronic hepatitis. 

Alcoholic Hepatitis 

Alcoholic hepatitis is caused by excessive alcohol consumption over many years and is not related to infectious hepatitis. 

It is the second stage of alcoholic fatty liver disease. In its mild form, it can be reversed by going teetotal. If it is severe, it can progress further. 

Autoimmune Hepatitis

This is a rare autoimmune condition in which the immune system attacks the liver. As it is a long-term condition, eventually the liver becomes significantly damaged and can stop functioning. Much like the majority of autoimmune diseases, the cause is unknown.⁶

Cirrhosis

Cirrhosis is the scarring of the liver as a result of long-term liver damage. The scarring prevents the liver from functioning properly. It is sometimes called ‘end-stage liver disease’ as it occurs after other stages in many different liver conditions, such as hepatitis. Cirrhosis can lead to liver failure, resulting in many serious consequences. There are no treatment options, and instead, treatment involves managing symptoms and preventing the cirrhosis from progressing.⁷ 

Other causes

Some less common causes are:

• Cancer
• Coeliac’s disease²

Risk factors

The risk factors for elevated liver enzymes are:

• Alcohol
• Certain medications
• Diabetes
• Family history 
• Hepatitis

The connection between liver and heart disease

The link between the cardiovascular system and Liver

The liver has a high demand for blood given its role and receives 25% of cardiac output. Of this 25% of blood, a quarter is delivered by the hepatic artery and is well-oxygenated in order to provide the liver cells with oxygen for proper functioning. The other three quarters is deoxygenated blood from the digestive system which enters by the hepatic portal vein. The deoxygenated blood flows through the liver for filtration and processing.⁸

What is heart disease?

Cardiovascular disease, also known as heart disease, describes conditions that affect the heart or blood vessels. The causes of cardiovascular disease are associated with a build-up of fatty deposits in blood vessels, particularly the arteries (the blood vessels that carry blood away from the heart, to the rest of the body). It is also associated with an increased risk of blood clots.⁹ 

As the term cardiovascular disease encompasses many different conditions, the list of symptoms is dependent on the type of disease.

Heart failure is defined as the inability of the heart to pump blood around the body properly, usually due to weakness or stiffness. It doesn’t mean that the heart has stopped working,instead means that it is unable to function effectively.¹⁰

Linking heart disease and liver disease

A lot of research has been conducted linking the two diseases, both of which can have detrimental consequences on the rest of the body if not managed properly.

Heart failure can lead to conditions that affect the liver - this is because the liver requires good blood flow in order to function well and in order to do its job in adjusting blood-sugar levels, blood proteins, and bilirubin clearance.

Conditions that may arise include:

• Ischemic hepatitis: also known as ‘liver shock,’ decreased blood flow from the heart causes the decreased blood flow in the liver. This causes hepatic cells to die due to oxygen deprivation. Enzyme levels will increase as well as toxic waste products.¹¹
• Although it is termed ‘hepatitis’ suggesting inflammation of the liver, there is no inflammation and instead cell death occurs. Instead, it is called ‘hepatitis’ as the clinical results are the same as those in acute viral hepatitis. The damaged and dying cells release aminotransferase enzymes into the blood, meaning that there is a significant increase in AST and ALT enzymes. Another enzyme that is significantly raised is lactate dehydrogenase (LDH). LDH is an enzyme that the body uses in order to make energy when there is no oxygen available. The raised LDH levels indicate that the liver isn’t receiving good blood flow, suggesting ischaemic damage. Severe jaundice also occurs as bilirubin levels are significantly increased (the liver is unable to clear it).¹²

• Congestive hepatopathy: occurs as a result of right-sided heart failure. The inferior vena cava is the large vein that carries blood back into the heart from the lower body. This vein can get congested due to heart failure and the blood will then back into veins that drain into the inferior vena cava. This includes the hepatic veins; if the pressure is high enough to push it back into the hepatic veins, the blood can become congested enough in the liver to cause it to malfunction.¹³ The enzymes ALT and AST may be elevated, indicating hepatic effects due to cardiac problems. This would be in conjunction with right-sided heart failure.¹⁴

Diagnosis

Diagnosing elevated liver enzymes involves doing a liver function test (LFT) or liver panel test. A liver function test is a blood test used to monitor and diagnose liver disease and damage. It looks at the products of the liver’s functions like small proteins and also the clearance of bilirubin. The tests sometimes look at liver enzyme levels also. Commonly looked-at enzymes include ALT, AST, ALP, and GGT.¹⁵ 

This blood test would be done if liver damage was suspected: either via exhibiting symptoms of liver damage or in order to ensure liver damage doesn’t occur as a consequence of cardiovascular disease. 

Treatments

Treating elevated liver enzymes involves treating the cause of the elevated enzymes. In the case of hepatic conditions caused as a result of cardiovascular conditions, treatment looks at the prevention of the cardiovascular condition. Sometimes this may require surgical intervention and other times there may be a combination of treatment options such as lifestyle changes and medications.

Treating elevated liver enzymes as a result of liver disease would mean preventing liver disease if it is reversible (such as fatty liver disease) or preventing further damage (such as cirrhosis).

For conditions such as alcoholic fatty liver disease, cutting out alcohol addresses the condition and gives the liver a chance to reverse the damage. 

Advice on how to normalise liver enzymes level

​​As liver enzymes tend to be elevated as a result of liver disease, normalising elevated liver enzymes involves preventing liver disease and avoiding its risk factors where possible. 

Some causes of liver disease are genetic and unpreventable, whilst many are environmental:

• Alcohol - Drinking alcohol in moderation is key to preventing alcohol-related liver diseases 
• Needles - Do not share needles or blood products as they may be infected
• Diet - Eating a well-balanced diet allows for a healthy digestive system and good functioning of the liver
• Vaccine -  there are vaccines available against viral hepatitises, some of which are compulsory for healthcare workers. Hepatitis A is also available as a travel vaccine for when traveling to endemic regions
• Blood sugar - if you have diabetes, managing blood sugar levels can prevent damaging the liver
• Exercise - exercising regularly and maintaining a healthy weight can help in preventing the buildup of excess fat in the liver

Summary

The liver is a fascinating organ that is able to regenerate itself following damage. It is responsible for many processes including adjusting blood glucose levels and filtering and  removing toxic chemicals from the blood. All of these processes involve the use of enzymes. 

As the liver is involved in filtering the blood, sometimes cardiovascular diseases can have hepatic consequences. This in turn causes elevated liver enzymes when the hepatic cells become damaged. 

Treating the elevated liver enzymes involves treating the condition that causes the elevation.

The normalisation of liver enzymes can also be helped via lifestyle factors such as watching blood sugar levels (especially as a diabetic) and watching your weight via good diet and exercise.