About hypertriglyceridaemia

Classification

The classification of hypertriglyceridaemia is evolving but a triglyceride (TG) level ≥1.7 mmol/L (150 mg/dL) is typically considered to be elevated.^1,2

Recent European Atherosclerosis Society (EAS) consensus definitions of a normal TG level and hypertriglyceridaemia are:¹

Category	Triglyceride level mmol/L (mg/dL)
Optimal	<1.2 (<100)
Borderline	1.2-1.7 (100-150)
Moderately elevated	1.7-5.7 (150-500)
Severe	5.7-10.0 (500-880)
Extreme	>10 (>880)

The American College of Cardiology (ACC) defines hypertriglyceridaemia as:²

Category	Triglyceride level (mg/dL)
Mild to moderate hypertriglyceridaemia	≥150 (fasting)/≥175 (non-fasting)
Severe	≥500 (fasting)

Epidemiology

Hypertriglyceridaemia is a common problem in clinical practice and its prevalence is increasing alongside that of obesity and type 2 diabetes.³ In the Copenhagen General Population Study, 27% of patients had non-fasting TG levels of 2-10 mmol/L (176-880 mg/dL) and 0.1% had non-fasting TG levels >10 mmol/L (>880 mg/dL).⁴

 

Hypertriglyceridaemia is associated with increased risk of atherosclerotic cardiovascular disease (ASCVD)^1,2 and, in more severe cases (TG >10 mmol/L [>885 mg/dL]), with pancreatitis.³  

In the Copenhagen City Heart Study, there was an approximately three to four-fold increased risk of myocardial infarction at moderately elevated TG levels.^4,5

Aetiology

The primary causes of hypertriglyceridaemia are genetic, with both mono- and polygenic involvement.³

Secondary causes of hypertriglyceridaemia can be summarised as:³

Dietary Increased alcohol consumption Metabolic syndrome Insulin resistance Diabetes mellitus (predominantly Type 2) Hypothyroidism Renal disease (proteinuria, uraemia, or glomerulonephritis) Pregnancy (particularly in the third trimester) Paraproteinaemia Systemic lupus erythematosis

Medicines including: Corticosteroids Oral oestrogen Tamoxifen Thiazides Non-cardioselective beta-blockers and bile acid sequestrants Cyclophosphamide L-asparaginase Protease inhibitors Second-generation antipsychotic agents (eg. clozapine and olanzapine)

References

1. Ginsberg HN, Packard CJ, Chapman MJ et al. Triglyceride-rich lipoproteins and their remnants: metabolic insights, role in atherosclerotic cardiovascular disease, and emerging therapeutic strategies—a consensus statement from the European Atherosclerosis Society. European Heart Journal 2021 Dec 14; 42(47):4791-4806. 
2. Virani SS, Morris PB, Agarwala A et al. 2021 ACC Expert consensus decision pathway on the management of ASCVD risk reduction in patients with persistent hypertriglyceridemia. J am Coll Cardiol 2021; Aug, 78 (9) 960–993
3. Laufs U, Parhofer KG, Ginsberg HN et al. Clinical review on triglycerides. European Heart Journal 2020; 41:99-109
4. Nordestgaard BG. Triglyceride-Rich Lipoproteins and Atherosclerotic Cardiovascular Disease: New Insights From Epidemiology, Genetics, and Biology. Circ Res. 2016 Feb 19;118(4):547-63
5. Nordestgaard BG, Varbo A. Triglycerides and cardiovascular disease. Lancet. 2014; 384:626–635