Metabolic effects of hormonal contraception in women with and without polycystic ovary syndrome

Hormonal contraceptives are widely used for birth control and for the treatment of symptoms related to polycystic ovary syndrome (PCOS), such as menstrual irregularities, hirsutism and acne. PCOS increases the risk for type 2 diabetes mellitus (T2DM), a main risk factor of cardiovascular morbidity. Combined hormonal contraception (CHC) has been associated with metabolic disturbances in several studies, but their results are still controversial, and there are few studies focusing on the effects of CHCs in women with PCOS.
The current study aimed to investigate whether the use of hormonal contraceptives is associated with glucose metabolism disturbances in healthy women and glucose and lipid metabolism disturbances and inflammation in women diagnosed with PCOS.
The study population mainly consisted of the follow-up study of the prospective, population-based Northern Finland Birth Cohort 1966 (NFBC1966) at age 46. Our results showed that current use of CHCs was associated with an increased risk of prediabetes and T2DM, whereas former, long-term use, over 10 years, was associated with an increased risk for prediabetes only. Current or former use of progestin-only contraceptives was not associated with any glucose metabolism disorders.
The study population of Study III consisted of 24 women with PCOS 18-35 years, who were recruited to use either an oral or a vaginal CHC preparation continuously for 9 weeks. Both oral and vaginal CHC preparations induced unbeneficial changes in glucose metabolism, lipid profile and low-grade inflammation.
These results highlight the importance of glucose tolerance in perimenopausal women using CHCs and in women with PCOS. Furthermore, the results raise the question of whether it is more appropriate to recommend alternative contraception to CHCs in women with known metabolic risks.