As part of a lipid profile during a medical examination, after a diagnosis of pancreatitis, or if you are being treated for high triglycerides
A blood sample taken from a vein in the arm
None. Fasting is not routinely required when checking triglyceride concentration (the guidance on this changed in 2014). However, there may be circumstances when fasting is still required, so follow your doctor's advice.
This test measures the amount of triglycerides in your blood. Triglycerides are the body's storage form of fat. Most triglycerides are found in fat (adipose) tissue, but some circulate in the blood to provide fuel for muscles to work. Extra triglycerides are found in the blood after eating a meal — when fat is being sent from the gut to fat tissue for storage. Triglycerides are the ‘saturated’ and ‘unsaturated’ fats you read about on food labels.
How is it used?
The most common reason for checking triglycerides is as part of a lipid profile to estimate risk of development of cardiovascular disease. Triglycerides are a form of lipid (fat), and are therefore included as part of a lipid profile. However, unlike cholesterol, which is very clearly an important cause of cardiovascular disease, the relationship between triglycerides and cardiovascular disease is less marked but still important. Therefore it is better to aim to keep your blood triglyceride concentrations low, particularly if you are at risk of cardiovascular disease for another reason.
Having high triglycerides can also lead to a serious medical condition called pancreatitis, which is inflammation of the pancreas gland. Therefore, if you get pancreatitis, triglyceride concentrations in the bloodstream should be checked to see if this is the cause. There are many other causes however.
When is it requested?
Lipid profile, including triglycerides, is commonly tested by your GP when you reach the age of 40, as part of a routine cardiovascular health check. It will also be checked if you are already thought to be at risk of cardiovascular disease for another reason, such as having diabetes, high blood pressure, being a smoker, or being overweight.
Due to the link between high triglycerides and pancreatitis, triglyceride concentrations will be checked if you are diagnosed with this condition.
What does the test result mean?
Having high triglycerides is thought to put you at higher risk of developing cardiovascular disease. This may also be because high triglycerides can be associated with an underlying condition, such as diabetes or obesity, which also increases cardiovascular risk.
If your triglyceride concentration is very high (e.g. at least 10-15 mmol/L), this indicates you are at risk of pancreatitis. In these circumstances, it is important to try and lower your triglyceride levels, which might involve either drugs or lifestyle changes, depending on the cause.
There are many factors which can cause high triglycerides. Examples include a high fat or high sugar diet, high intake of alcohol, obesity and diabetes. Lifestyle changes can therefore be very effective in reducing triglyceride levels. Drug treatments are also available if lifestyle changes are insufficient. There are also genetic factors which increase triglyceride levels.
Is there anything else I should know?
If you are diabetic and your blood glucose concentrations are out of control, triglyceride concentrations will be very high.
Triglyceride levels in the blood may change dramatically after a meal. Even fasting levels vary considerably from day to day. Because of the day to day variation modest changes in fasting triglycerides measured on different days are not considered to be unusual or abnormal.
There are rare genetic conditions resulting in very high levels of triglyceride from birth resulting in pancreatitis in childhood (lipoprotein lipase deficiency or familial chylomicronaemia syndrome). An RNA treatment is now available for this condition however management is mostly based on very low fat diets.
Don't I need to fast before having my triglycerides measured?
Previously, fasting for 12 hours was recommended, as triglycerides increase after a meal for several hours. However, studies now show that readings after a meal are just as useful as fasting levels. There may be instances where your doctor recommends having the sample taken when fasting, so follow their advice.
What type of diet is best for healthy triglyceride levels?
Since triglycerides are circulating forms of fat, you might think that a high fat diet will raise triglycerides and a low fat diet would lower triglycerides. This is true, but carbohydrate also has a very important effect on triglycerides. Diets high in carbohydrates, especially sugar, lead to increases in triglycerides as do diets rich in fats.
Can exercise help with triglyceride levels?
Can I monitor triglyceride levels at home?