Comparative metabolic effects of three types of combined oral contraceptive pills in Chinese women.

ABSTRACT

The results of a prospective longitudinal controlled study comparing some metabolic effects of a low-dose levonorgestrel-ethinyl oestradiol combined oral contraceptive (Microgynon 30), a desogestrel-ethinyl oestradiol-containing pill (Marvelon) and a levonorgestrel-ethinyl oestradiol triphasic preparation (Triquilar) after one year of treatment in ethnic Chinese women are presented. Serum cholesterol levels are similar for the three pills at 6 and 12 months of treatment. Marvelon and Triquilar users showed rises in triglyceride levels while Microgynon 30 users had no change after one year of treatment. Lipoprotein fractions showed favourable changes in Triquilar and Marvelon users with significant rise in HDL fractions at 6 and 12 months; Microgynon 30 users had equivocal changes in HDL fractions. Carbohydrate metabolism as reflected by glucose tolerance showed deterioration with all 3 pills, being least with Microgynon 30 and greatest with Marvelon at 12 months.

ABSTRACT

PIP Synthetic estrogens and gonane progestagens aggravate a predisposition to cardiovascular disease by altering carbohydrate and lipoprotein metabolism. This paper compares the metabolic effects of the triphasic oral contraceptive Triquilar (3 mcg ethinyl estradiol + 50 mcg levonorgestrel for 6 days, 40 mcg ethinyl estradiol + 75 mcg levonorgestrol for 5 days, and 30 mcg ethinyl estradiol + 125 mcg levonorgestrel for 10 days) and a combined oral contraceptive Marvelon (30 mcg ethinyl estradiol + 150 mcg desogestrel) with the standard low-dose combined oral contraceptive Microgynon 30 (30 mcg ethinyl estradiol + 150 mcg levonorgestrel) on an ethnic Chinese population. 125 fertile women aged 18-34 with regular menstrual cycles, who had not taken any form of hormonal contraceptive for the preceeding 6 months, were randomly allocated to Microgynon 30 (30 women), Triquilar (39 women), or Marvelon (32 women). Blood samples were examined for lipids, lipoproteins, and glucose before treatment and after 6 and 12 month. Serum triglyceride levels were unchanged by Microgynon 30 but were elevated 30-40% by Triquilar and Marvelon. Serum cholesterol levels were not altered by any of the 3 pill types. Microgynon 30 did not alter triglyceride lipoprotein fractions, but both Triquilar and Marvelon elevated them, with the high density lipoprotein fraction. Cholesterol lipoprotein fraction (free and total) were altered by all 3 pill types. Microgynon 30 lowered both low and high density (free and total cholesterol) lipoproteins. Marvelon and Triquilar had no effect on very low density lipoprotein levels but effected 10% decrease in the level of low density (free and total cholesterol) lipoproteins. The high density lipoprotein (free and total cholesterol) fraction rose 10% with Triquilar and 20% with Marvelon. Thus the triphasic and desogestrel oral contraceptives brought about a favorable alteration in the low density lipoprotein high density lipoprotein cholesterol ratios. All 3 pill types caused a deterioration in glucose tolerance, but the effect was least with Micrognon 30.