High triglycerides: what the result means and what to do

HEART UK explains that triglycerides are a combination of three fatty acids and glycerol, and that we have two supplies: one from food, absorbed by the intestines and carried as chylomicrons, and one made by the liver, carried as VLDL. Triglycerides are measured with a simple blood test, usually as part of the lipid profile that the NHS describes as measuring cholesterol levels to check the risk of cardiovascular disease and stroke.

HEART UK says triglyceride levels should be measured when you have a cholesterol test, and that national guidelines no longer recommend fasting. If a fasting sample is requested, usually for 10 to 14 hours, the target is lower because only liver-made triglycerides are measured.

HEART UK states that you should aim for a non-fasting level below 2.0mmol/L and a fasting level below 1.7mmol/L. NHS Highland, writing for clinicians in Scotland, uses bands of 2 to 10 mmol/L, 10 to 20 mmol/L and above 20 mmol/L for deciding what to do. Because a non-fasting sample includes triglycerides from a recent meal, a repeat sample is sometimes used to see whether a high reading was a one-off.

HEART UK divides causes into primary and secondary. Primary causes are inherited conditions such as familial hypertriglyceridaemia, familial combined hyperlipidaemia, type 3 hyperlipidaemia and the rarer familial chylomicronaemia syndrome. Secondary causes include lifestyle and other conditions.

The lifestyle causes it lists are a sedentary lifestyle, an unhealthy diet, particularly high in saturated fats and added sugars, and alcohol, to which some people are very sensitive even in small amounts. Medical conditions include kidney disease, non-alcoholic fatty liver disease, gout, pregnancy and an underactive thyroid. Medicines include some diuretics, steroids, oral oestrogen therapy, retinoids and retrovirals. HEART UK also notes that high triglycerides are often accompanied by low HDL cholesterol, a pattern linked with heart disease that often occurs in people who are very overweight, have type 2 diabetes or have metabolic syndrome.

NHS Highland adds a longer list of medicines that can cause severe elevation, including oral oestrogen, tamoxifen and raloxifene, oral retinoids, some chemotherapy drugs, protease inhibitors, propofol, interferon and immunosuppressants.

HEART UK recommends maintaining a healthy weight and shape, particularly reducing weight carried around the middle; being physically active, aiming for at least 150 minutes a week at a moderate intensity; replacing saturated fats with unsaturated fats; choosing wholegrains rather than refined starchy foods; cutting down on added sugars; eating plenty of fruit and vegetables, at least five portions a day; eating fish twice a week, one of them oily; and drinking no more than 14 units of alcohol a week, with some people needing to cut down further.

If lifestyle changes do not lower triglycerides enough or there is a genetic condition, HEART UK says medication may be needed. Statins are usually first-line, and cholesterol specialists may also prescribe fibrates and omega 3 acid ethyl esters. NHS Highland suggests that for people with levels above 10 mmol/L where no reversible cause can be removed, bezafibrate and referral to a lipid clinic are considered.

Do not stop or start medicines on the strength of a single result. Your GP can review your whole cholesterol profile, which NHS Highland notes is often assessed using non-HDL cholesterol in these patients because LDL cholesterol cannot be calculated reliably at higher triglyceride levels.

HEART UK says very high triglyceride levels can cause serious medical conditions such as pancreatitis. NHS Highland cites cohort studies indicating that acute pancreatitis may occur in 3% of people with levels of 10 to 20 mmol/L and 15% of those above 20 mmol/L. Guidance for clinicians in that area is to assess promptly for pancreatitis and high blood sugar, to look at alcohol intake, and to treat the cause.

If you have severe pain in the upper abdomen that spreads to the back, repeated vomiting or you feel very unwell, seek emergency care through 999 or A&E. If a very high triglyceride result is phoned through by the laboratory or your surgery, follow the advice you are given promptly.

Triglycerides are usually measured within an NHS cholesterol check or cardiovascular risk assessment. Private health checks often report the same test. In either case, a raised level is best discussed with a GP who can review diet, alcohol, medicines, diabetes and thyroid status and decide whether to repeat the test or refer to a lipid clinic.