Adverse change in low-density lipoprotein subfractions profile with oestrogen-only hormone replacement therapy

In a prospective longitudinal study in 17 women, we investigated the effects of surgical menopause and subsequent oestrogen-only hormone replacement therapy (HRT) on plasma concentrations of total cholesterol, HDL cholesterol, LDL cholesterol, triglyceride and LDL subfractions profile. Plasma LDL is a heterogeneous population of particles of varying size, density and chemical composition. The predominance of small LDL particles is a newly-recognized risk factor for coronary artery disease. The LDL score is used to describe LDL subfractions profile and the greater the score, the higher the proportion of small LDL particles. Six weeks after hysterectomy and bilateral oopherectomy, total cholesterol and triglyceride concentrations were significantly increased (p < 0.01) as well as the LDL score (p < 0.05). After 6 weeks of oestrogen-only HRT, total cholesterol concentration was significantly lower and HDL cholesterol concentration significantly higher than before the treatment (p < 0.05). At the same time, mean LDL score significantly increased and in none of the women did LDL subfractions profile change favourably.