Effects of two oral contraceptives on plasma levels of nitric oxide, homocysteine, and lipid metabolism

Abstract

This prospective study was performed to investigate the effect of 2 low-dose oral contraceptives containing a second- and a third-generation progestagen on factors, which may influence the individual cardiovascular risk by regulating endothelial function and development of atherosclerosis. Sixteen women were randomized to receive 3 cycles of treatment with 30 microg ethinylestradiol/150 microg levonorgestrel (EE/LNG) and 3 cycles of treatment with 30 microg ethinylestradiol/75 microg gestodene (EE/GSD). Before and after treatment the plasma levels of nitric oxide (NO), homocysteine, cholesterol, high-density lipoprotein (HDL), and triglycerides were measured. No significant alterations of the NO, homocysteine, and triglyceride plasma levels were observed during use of both contraceptive pills. Compared to levels after EE/LNG treatment, HDL plasma levels were higher (P =.05) and the cholesterol/HDL ratio was lower after the EE/GSD pill (P =.05). Significant correlations were found between NO and homocysteine and NO and cholesterol. Our data indicate that the cardiovascular risk associated with these contraceptive pills may not be explained by a negative influence on NO or homocysteine.