Objective: The aim of this study was to evaluate the effects of hyperinsulinaemia and insulin resistance (IR) on reproductive and metabolic disorders and fertility in women with polycystic ovary syndrome (PCOS).
Design, setting, participants and measurements: This was a multicenter, randomized controlled trial involving a total of 1000 women diagnosed with PCOS according to the modified Rotterdam criteria at 21 sites (27 hospitals). We evaluated the effects of serum insulin levels and HOMA-IR on parameters and outcomes. The main outcome measures were anthropometric, biometric and ultrasound parameters at baseline and the clinical outcomes of ovulation, conception, pregnancy, live birth and pregnancy loss.
Results: The relevant analysis between hyperinsulinaemia and IR and clinical characteristics showed that weight, waist and hip circumference, BMI, waist-to-hip ratio, acanthosis nigricans score and menstrual period were significantly correlated with fasting insulin (FIN) and HOMA-IR. There was no significant correlation between the hirsutism score or acne score with FIN or HOMA-IR. The relevant analysis between hyperinsulinaemia and IR and circulating sex steroids and gonadotrophins showed that FAI was significantly correlated with FIN and HOMA-IR (r = 0.240, P < 0.001 and r = 0.191, P < 0.001, respectively). Free testosterone was significantly correlated with FIN after adjusting for the influence of age. LH and LH/FSH were not related to FIN or HOMA-IR after statistical correction for differences in BMI. The relevant analysis between hyperinsulinaemia and IR and metabolic profile showed that FIN and HOMA-IR were positively associated with fasting glucose, cholesterol, triglycerides, low-density lipoprotein, Apo B, and the incidence of metabolic syndrome and were negatively associated with high-density lipoprotein. The predictive analysis between hyperinsulinaemia and IR with fertility showed that the levels of FIN and HOMA-IR were related to the fertility outcome (ovulation, pregnancy, conception or live birth) in patients with PCOS. After adjustments for age, total testosterone and free testosterone, increasing serum insulin levels and HOMA-IR were significantly associated with decreased cycle ovulation, conception, pregnancy and live birth rates.
Conclusions: Hyperinsulinaemia and IR are associated with reproductive and metabolic disorders and can predict the fertility outcomes in PCOS patients.
Trial registration: ClinicalTrials.gov NCT01573858.
Keywords: IR; fertility; hyperinsulinaemia; polycystic ovary syndrome.
© 2019 John Wiley & Sons Ltd.