The impact of GnRH agonist and menotropin therapy on lipoprotein metabolism

Two groups of women, 48 undergoing controlled ovarian hyperstimulation for in vitro fertilization (IVF) treatment with a gonadotropin-releasing hormone (GnRH) analog and human menopausal gonadotropin daily and a group of 15 treated with a GnRH analog using the 'luteal phase protocol' before the hyperstimulation for IVF, took part in a prospective randomized study at the IVF Unit of the Beilinson Medical Center, Israel. The aim was to evaluate the changes in lipid metabolism occurring in the course of a standard controlled ovarian hyperstimulation protocol during IVF treatment cycles by measuring serum lipid levels before and after treatment. In the former group, in parallel with the 17β-estradiol increase, the cholesterol and low-density lipoprotein-cholesterol levels dropped and the high-density lipoprotein-cholesterol levels increased significantly. The resultant atherogenic decrease demonstrated a statistically significant decrease. In the latter group the mean lipoprotein levels were slightly different after treatment, but no statistically significant difference was observed. Our results indicate that the GnRH analog alone, administered for 10-12 days, does not induce any significant change in serum lipid levels. When using a combination of a GnRH analog and menotropins, the change of lipoprotein levels is favorable.