Treatment of Hypertriglyceridemia

Classification of Triglyceride Levels

Goals of Treatment

• Mild-to-moderate (150–1000 mg/dL): Reduce remnant cholesterol (VLDL-C) to lower ASCVD risk. LDL-C control is the primary initial aim; triglyceride lowering is secondary.
• Severe (> 1000 mg/dL): Prevent acute pancreatitis — triglyceride reduction becomes the primary goal.

1. Lifestyle Modifications (Foundation of All Treatment)

• Weight loss — the most common cause of hypertriglyceridemia is obesity with polygenic predisposition
• Very-low-fat diet (≤ 15% of calories) for very high TG levels
• Low-carbohydrate diet — reduces hepatic VLDL production
• Exercise / increased physical activity
• Avoid precipitating agents:
  • Alcohol
  • Oral estrogens, glucocorticoids, β-blockers, tamoxifen, cyclosporine, antiretrovirals, retinoids
• Optimize glycemic control in diabetes (insulin resistance drives hypertriglyceridemia)

2. Pharmacologic Treatment

A. Statins (First-line for mild–moderate HTG with ASCVD risk)

• High-intensity statins (atorvastatin, rosuvastatin) reduce both LDL-C and triglyceride-rich lipoproteins/remnant-C
• Reduce TG by ~15–30% (dose-dependent)
• The only class with proven cardiovascular mortality reduction

B. Fibrates (Fenofibrate, Gemfibrozil)

• Reduce TG by 30–45%
• Fenofibrate is preferred over gemfibrozil when used with statins — gemfibrozil inhibits statin glucuronidation, markedly increasing myopathy risk; gemfibrozil is contraindicated with simvastatin
• Particularly useful in type III hyperlipidemia (dysbetalipoproteinemia)
• Indications: Very high TG (pancreatitis prevention), or as add-on to high-intensity statin in mild-moderate HTG with residual ASCVD risk
• Adverse effects: GI disturbance, gallstone formation (↑ biliary cholesterol), myositis (especially with gemfibrozil + statin), ↑ INR with warfarin
• Avoid in: Severe hepatic/renal dysfunction, pre-existing gallbladder disease

C. Prescription Omega-3 Fatty Acids (Icosapent Ethyl / EPA + DHA)

• Reduce TG by 25–40% at doses of 1.5–4.5 g/day
• Icosapent ethyl (EPA only, 4 g/day): REDUCE-IT trial showed significant ASCVD event reduction in statin-treated patients with elevated TG — this is the preferred formulation for ASCVD risk reduction
• EPA + DHA combination (e.g., Vascepa vs. Lovaza): STRENGTH trial (EPA+DHA) was terminated for futility — ASCVD benefit appears specific to pure EPA
• No significant drug interactions with statins or fibrates
• Main side effect: eructation with fishy taste (mitigated by freezing capsules)
• Can be added to high-intensity statin when TG remains elevated

D. Niacin (Nicotinic Acid)

• Reduces TG by 20–50%; also reduces LDL-C ~10–20% and raises HDL-C up to 30%
• Mechanism: Strongly inhibits lipolysis in adipose tissue → ↓ free fatty acids → ↓ hepatic VLDL production
• Limitation: Clinical trials (AIM-HIGH, HPS2-THRIVE) showed no added ASCVD benefit when combined with a statin
• Raises fasting glucose — use with caution in diabetes/metabolic syndrome
• Adverse effects: flushing, hyperglycemia, hepatotoxicity, hyperuricemia
• Largely fallen out of favor for ASCVD prevention

E. Bile Acid Sequestrants — ⚠️ Use with Caution

• Can worsen hypertriglyceridemia — contraindicated or used cautiously when TG > 300 mg/dL

3. Newer / Emerging Agents (Severe HTG > 1000 mg/dL)

• Volanesorsen (apoC-III antisense oligonucleotide) — reduces apoC-III, which normally inhibits lipoprotein lipase; approved in some countries for familial chylomicronemia syndrome
• Agents in development targeting ANGPTL3, APOC3 for severe/refractory hypertriglyceridemia
• Patients with severe HTG often have mutations in lipoprotein lipase — consider genetic work-up when fibrate + low-fat diet fails to normalize TG

Treatment Algorithm Summary

TG 150–499 mg/dL
  → Lifestyle first (weight loss, diet, exercise)
  → Treat LDL-C as primary target (statin)
  → If TG remains elevated + high ASCVD risk: add icosapent ethyl (EPA 4g/d) or fibrate

TG 500–999 mg/dL
  → Lifestyle + very-low-fat diet (≤15% calories)
  → Fibrate or omega-3 to prevent pancreatitis
  → Statin if ASCVD risk present

TG ≥ 1000 mg/dL
  → EMERGENCY: pancreatitis prevention
  → Very-low-fat diet + abstinence from alcohol
  → Fibrate ± omega-3
  → Rule out secondary causes (DM, hypothyroidism, alcohol, drugs)
  → Consider familial chylomicronemia if refractory

Secondary Causes to Always Address