Treating hypertriglyceridemia

I wish to provide evidence-based information to correct statements made in the informative and well-written article by George Yuan and colleagues on hypertriglyceridemia1 with respect to the potential use of omega-3 fatty acids from fish oils to lower triglyceride levels. The authors state that “daily consumption of 4 g of omega-3 fatty acids, along with restricted energy and saturated-fat intakes, can reduce plasma triglyceride levels by as much as 20%. However, omega-3 fatty acids are rarely effective when used as the sole triglyceride-lowering therapy.” An earlier review in CMAJ outlined evidence for a pronounced effect upon supplementation with docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA).2 Calculations from the 65 intervention trials reviewed by Harris3 indicate that plasma triglyceride levels should be reduced by 25%–30% in people with baseline fasting triglyceride levels of 1.70–2.82 mmol/L who take 3 g of supplemental DHA/EPA (combined) per day as their sole triglyceride-lowering therapy. These effects typically occur within 4 weeks in the absence of any significant change in diet. The American Heart Association states that “for individuals with hypertriglyceridemia, 2 to 4 g of DHA/EPA per day, provided as capsules under a physician's care, are recommended.”4

A reduction in triglyceride levels of 30% or more with 4 g of DHA/EPA per day may be accompanied by a small but significant (5%–10%) increase in low-density lipoprotein cholesterol levels.3 The indirect determination of low-density lipoprotein cholesterol levels by the Friedewald equation will often yield a small increase whenever triglyceride levels are lowered.

DHA/EPA supplementation should be considered as an additional therapeutic option for hypertriglyceridemia. It is efficacious, safe in most patients and less expensive than most other therapies for triglyceride management, and patient compliance is usually good.5 A recent review concluded that combination therapy with statins and DHA/EPA supplementation has been “consistently shown to be an effective, safe, and well-tolerated treatment for combined dyslipidemia.”6