Lipids and HRT

Oestrogen replacement in HRT have various effects on lipid profile

• there is an elevation of the high density lipoprotein cholesterol level and a lowering of the low density lipoprotein cholesterol level
• there is a tendency for oestrogen to increase serum triglyceride levels (via an increase in hepatic VLDL production) - administration of oestrogen in women with a pre-existing hypertriglyceridaemia can cause gross hyperchylomicronaemia (and predispose to acute pancreatitis)

However there is evidence that the use of HRT can lead to an increase in the incidence of myocardial infarctions - in the Women's Health Initiative study there was a relative risk 1.29 at 5.2 years of myocardial infarction (comparing oestrogen plus progestogen arm vs. placebo group) (1).

Reference:

1. Writing Group for the Women's Health Initiative Investigators. Risks and benefits of estrogen plus progestin in healthy postmenopausal women. Principal results for the Women's Health Initiative Randomized controlled trial. JAMA 2002; 288:321-333.
2. British Heart Foundation Factfile (12/1996). Hormone Replacement Therapy.