Lipid and carbohydrate metabolism in premenopausal women given subdermal estradiol implants

Fifteen premenopausal women were studied before and 6 weeks after receiving subcutaneous implants of 100 mg estradiol. Serum estradiol levels doubled; increases were also seen in fasting serum total cholesterol and in high-density lipoprotein cholesterol (HDL). This increase was confined to the HDL2 subfraction, and was not reflected in the HDL apolipoproteins. Low density lipoprotein (LDL) cholesterol levels were unchanged, as were those of apolipoprotein B, the major protein component of LDL. Carbohydrate metabolism was assessed in a subgroup of 12 women. Estrogen implantation reduced fasting plasma glucose levels but did not alter the plasma glucose response to an oral glucose tolerance test. Plasma insulin levels were unchanged both in the fasted state and during the glucose tolerance test. Our findings indicate that parenteral administration of estradiol can alter lipid and carbohydrate metabolism in premenopausal women.