High triglycerides: why they rise and how to really bring them down

High triglycerides are a very common finding, but they do not all mean the same thing. In practical terms, guidelines distinguish between levels of 150–499 mg/dL and levels of 500 mg/dL or more; from 500 mg/dL there is also concern about the risk of pancreatitis, and even more so at 1000 mg/dL or above. Understanding why they rise is key, because most cases seen in clinical practice are not due to a rare genetic cause but to a combination of metabolic factors, habits and secondary causes that need to be identified.

What triglycerides are and when they are considered high

Triglycerides are a type of fat that circulates in the blood. The body uses them as an energy reserve, but when their concentration rises above desirable levels, the context needs to be interpreted. A moderate rise, where overall cardiovascular risk usually matters most, is not the same as a severe rise, where concern about pancreatitis also comes into play.

That is why guidelines separate two practical scenarios: triglycerides of 150–499 mg/dL and triglycerides of 500 mg/dL or more. That cut-off is not merely academic: it indicates which risks matter most and what the priorities of the assessment usually are.

Why triglycerides really go up

In most people there is no single cause. The most common picture is multifactorial hypertriglyceridaemia: individual predisposition, visceral fat, insulin resistance, diet, alcohol, a sedentary lifestyle and other medical conditions all add up. Rare monogenic forms do exist, such as familial chylomicronaemia syndrome, but they are the exception.

From a metabolic point of view, visceral fat promotes insulin resistance, increases the flow of fatty acids to the liver, raises the liver's production of triglyceride-rich VLDL and impairs the clearance of triglyceride-rich particles. This is one of the reasons why high triglycerides so often appear alongside metabolic syndrome, prediabetes or metabolic fatty liver disease.

Guidelines also recommend looking for secondary causes before oversimplifying the problem. These include excess alcohol, poorly controlled diabetes, hypothyroidism, kidney or liver disease, nephrotic syndrome, diets high in added sugars and refined carbohydrates, a sedentary lifestyle and some medicines.

What is usually checked when they come back high

When triglycerides come back raised, the useful question is not only how far they have gone up, but what is driving them. Guidelines stress checking for correctable causes and working out whether the main problem is cardiometabolic or whether levels have already reached the point where preventing pancreatitis becomes the concern.

The wider clinical context matters too. If a person is carrying excess weight or has insulin resistance or other metabolic disturbances, the finding often fits into a broader pattern. In Spain, this problem has been studied both in primary care, through the SIMETAP-HTG study, which assessed 6,588 adults and found triglycerides of 150 mg/dL or more (or treatment to lower them) in 27% after adjusting for age and sex, 34.6% of men and 21.4% of women, and in a study in Catalonia covering a population of more than 3.5 million users, where levels of 500 mg/dL or more were much rarer (0.9% of those with recorded triglycerides) and almost always linked to a secondary cause, such as obesity or poorly controlled diabetes. The central point: it is a common problem and very much present in real-world practice.

How to really bring them down: what the guidelines say

The foundation of treatment usually lies in lifestyle. The Endocrine Society recommends that, in people with obesity, lifestyle measures should be the first-line treatment for lowering triglycerides, and places weight loss as first line for most patients with high triglycerides and overweight or obesity.

In practice, guidelines highlight cutting down on or cutting out alcohol, reducing added sugars and refined carbohydrates, avoiding excess calories, exercising and losing weight if there is overweight or obesity. Physical activity is also part of first-line treatment when cholesterol or triglycerides are raised.

In cases of severe hypertriglyceridaemia, a very low-fat diet may be needed to reduce the risk of pancreatitis. That scenario is different from a moderate rise and should be understood as such: not every high triglyceride result is managed with the same priority or the same goal.

When the problem is linked to excess weight, improving that metabolic background can have a wide-ranging impact, not just on triglycerides. In clinical research, for example, SURMOUNT-1 observed mean weight losses of 19.5% with 10 mg and 20.9% with 15 mg, compared with 3.1% with placebo. If you want to understand better why losing weight changes so many markers at once, it may help to read how GLP-1-based treatments work and why they have changed the approach to obesity.

Medicines in Spain: what role they really play

Not all treatments pursue the same goal. If the main problem is cardiovascular risk, statins remain the cornerstone because they reduce cardiovascular events. Fibrates, on the other hand, are used mainly when triglycerides are very high and the aim is to prevent pancreatitis, rather than as a general cardiovascular prevention strategy.

Fenofibrate and gemfibrozil presentations are marketed in Spain. According to its summary of product characteristics, fenofibrate activates PPAR-α, increasing lipolysis and the clearance of triglyceride-rich particles and reducing apoC-III. Even so, ACCORD-Lipid did not support the routine use of fenofibrate added to a statin to reduce cardiovascular events in high-risk diabetes.

Gemfibrozil is also available in Spain, and its summary of product characteristics indicates it as an adjunct to diet and non-drug measures. One important caveat is that it has interaction problems, including some with statins, so it is not a medicine to be considered in isolation from the rest of the treatment.

With omega-3, it is worth keeping concepts separate. The Cochrane review found that increasing intake lowers triglycerides slightly, but that does not mean any commercial supplement reduces heart attacks or strokes. If you are interested in that difference between medicines and unrealistic expectations, it is usually useful to weigh up evidence and marketing calmly.

In Spain, icosapent ethyl is marketed as Vazkepa and is indicated to reduce the risk of cardiovascular events in adults treated with statins who have high cardiovascular risk and high triglycerides of 150 mg/dL or more, in specific clinical profiles. In REDUCE-IT, the primary endpoint occurred in 17.2% with icosapent ethyl compared with 22.0% with placebo, with an HR of 0.75; the key secondary endpoint occurred in 11.2% compared with 14.8%, with an HR of 0.74. But even here the important lesson is not that ‘anything that lowers triglycerides protects the heart’, because PROMINENT, with pemafibrate, showed precisely the opposite.

At the rarest end of the spectrum is volanesorsen. It inhibits the formation of apoC-III, which regulates triglyceride metabolism and chylomicron clearance, but it is not indicated for the common hypertriglyceridaemia linked to overweight or diet. In Spain, Waylivra is indicated as an adjunct to diet in adults with genetically confirmed familial chylomicronaemia syndrome and a high risk of pancreatitis, when the response to diet and other treatments has been inadequate.

Ideas worth discarding

The first is that a blood test showing high triglycerides is read the same way in every case. A moderate rise does not mean the same as a severe one. The second is that lowering the number automatically reduces cardiovascular risk: that depends on the strategy, the clinical profile and the quality of the evidence.

The third is that ‘omega-3’ is some kind of magic category. There is a clear difference between a medicine evaluated in a clinical trial and any commercial supplement. And the fourth is that, when high triglycerides appear alongside excess weight, insulin resistance or sleep apnoea, the problem is usually broader than a single number. In that context it may help to read why obstructive sleep apnoea is linked to cardiometabolic risk or what happens when weight comes back after stopping a treatment.

What to take away from all this

The important idea is simple: high triglycerides are not a single disease, but a signal that needs to be interpreted properly. What matters is how far they have risen, whether there is a risk of pancreatitis and, above all, which metabolic or secondary factors are pushing them up. Today in Spain there are medical treatment options with a prior assessment, a prescription when appropriate from a registered doctor and ongoing follow-up, as part of a cardiometabolic and weight-loss approach. If you want to know whether that approach suits your case, you can check in a few minutes whether you are eligible.