What happens with HRT (especially estrogen)?
• Estrogen increases hepatic VLDL synthesis → which increases serum triglycerides.
• Especially with oral estrogen, the first-pass effect in the liverstrongly stimulates triglyceride production.
• This can exacerbate pre-existing hypertriglyceridemia.
Why is this dangerous?
Marked hypertriglyceridemia (typically >500–1000 mg/dL) can trigger:
• Acute pancreatitis
• Increased risk of thromboembolic events (estrogen already increases coagulation factors).
So giving HRT in someone with high triglycerides could tip them into pancreatitis or vascular complications.
Summary Table:
| Effect of Estrogen | Outcome |
|---|---|
| ↑ Hepatic VLDL synthesis | ↑ Triglycerides |
| ↑ Triglycerides in predisposed patients | Risk of pancreatitis |
| ↑ Coagulation factors | Thrombosis risk |
Clinical Tip:
• If estrogen is absolutely needed, transdermal estrogen(patch/gel) may be safer as it bypasses the liver, so less effect on triglycerides.
• But in severe hypertriglyceridemia, estrogen is avoided altogether.