Effects of Second and Third Generation Oral Contraceptives on Lipid and Carbohydrate Metabolism in Overweight and Obese Women: A Randomized Triple-Blind Controlled Trial

BACKGROUND Combined oral contraceptives (COCs) have not been shown to have major effects on lipid and carbohydrate metabolism in normal-weight women. However, we have limited information about the effects on women at high risk for cardiovascular disease and diabetes due to being overweight and obese. OBJECTIVES To evaluate the effects of second and third generation contraceptive pills on lipid and carbohydrate metabolism in overweight and obese women. PATIENTS AND METHODS This triple-blind controlled trial was performed on 137 healthy women aged 18 - 40 years with a body mass index of 25-34.9 (kg/m2) who were referred to health centers in Tabriz, Iran from 2014 to 2015. The women were randomly divided into groups who were to take 30 mcg ethinyl estradiol/150 mcg levonorgestrel (EE/LGN) (n = 69) or 30 mcg ethinyl estradiol/150 mcg desogestrel (EE/DSG) (n = 68) with an allocation ratio of 1: 1 for three cycles. As primary outcomes, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and fasting plasma glucose (FPG) were assessed; total cholesterol (TC), triglycerides (TG), and 2-hour plasma glucose in the 75-g oral glucose tolerance test (2-hour 75-g OGTT) were assessed as secondary outcomes. RESULTS The differences in lipid and carbohydrate parameters were not significant between the two groups, except for HDL-C (Adjusted MD (CI95%) = 7.00 (2.98 to 11.02)). HDL-C decreased with EE/LGN (P = 0.016) and increased with EE/DSG (P = 0.004). LDL-C and TC increased in both groups, whereas TG increased only with EE/DSG (P < 0.05). Compared with the baseline, FPG levels did not differ significantly in both groups, but EE/DSG increased 2-hour 75-g OGTT (P = 0.010). CONCLUSIONS We observed no significant differences between the two groups in lipid and carbohydrate metabolism, except for HDL-C. Considering the importance of overweight and obese women's health, studies with longer follow-up periods are recommended in this respect.