The effects of treatment with drospirenone/ethinyl oestradiol alone or in combination with metformin on elastic properties of aorta in women with polycystic ovary syndrome

Abstract

Polycystic ovary syndrome (PCOS) is a heterogeneous clinical condition. Oral contraceptive pills (OCPs) have conventionally been the mainstay of treatment for the amelioration of hyperandrogenism and regulation of menstrual cycles in women with PCOS. Metformin has beneficial effects on insulin resistance and endothelial functions. To our knowledge, the effect of metformin/OCP combination treatment on aortic stiffness has not been studied so far. The aim of this study was to investigate the effects of treatment with drospirenone/ethinyl oestradiol (E/E) alone or in combination with metformin on the elastic properties of the aorta in women with PCOS. Thirty-seven women with PCOS were enrolled in the study. The first treatment arm, which was treated with OCP alone, was described as the OCP group (19 patients, mean age: 23·2 ± 5·4); the other treatment arm, which was treated with OCP and metformin, was described as the combination group (18 patients, mean age: 23·0 ± 4·5). The elastic parameters of the aorta namely 'aortic strain', 'aortic distensibility', 'aortic diameter alteration' and 'aortic stiffness index' were calculated by the appropriate formulae. The hormonal profile, HOMA-IR score, basal insulin and glucose levels were studied in both groups. Before and after 6 months of treatment, echocardiographic measurements and laboratory tests were also obtained. After 6 months of treatment, significant weight loss and decrease in body mass index (BMI) were observed in the combination group (75·3 ± 13·3 kg to 72·3 ± 13·5 kg and 31·7 ± 7·3 kg/m² vs 30·4 ± 7·3 kg/m², P = 0·001 and P = 0·001, respectively). Conversely in the OCP group, BMI and weight were not significantly different after 6 months of treatment (68·8 ± 18·3 kg to 71·6 ± 21·2 kg and 26·4 ± 6·2 kg/m² to 27·4 ± 6·9 kg/m², P = 0·159 and P = 0·149, respectively). In addition, there were no significant differences in aortic strain, distensibility (7·7 ± 4·2 to 7·8 ± 3·6 and 7·2 ± 4·1 to 7·7 ± 3·6, P = 0·926 and P = 0·593, respectively) and stiffness index in the OCP group (8·8 ± 7·4 to 8·2 ± 6·7, P = 0·772). However, in the combination group, the adjusted values of the aortic stiffness index decreased significantly at the 6 months' follow-up (10·0 ± 1·5 to 6·7 ± 0·3, P = 0·021) and aortic distensibility and strain increased but not significantly (7·0 ± 4·3 to 9·3 ± 3·3 and 6·8 ± 3·9 to 9·4 ± 3·5, P = 0·163 and P = 0·071, respectively) at the 6 months' follow-up. We demonstrated an improvement in the elastic parameters of the aorta by adding metformin to OCP treatment. We suggest that metformin plus OCP treatment may decrease cardiovascular disease risk in women with PCOS.