The Effects of Adiponectin on Infertile Women Undergoing IVF/ICSI Treatment and on Human Granulosa Cells

Adiponectin, one of the most abundant adipocyte-secreted protein, has been involved in female reproductive regulation. This study aimed to 1) compare serum adiponectin levels in various phases of in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) treatment including Phase I (the beginning of gonadotropin stimulation), Phase II (around 8 days after gonadotropin stimulation), and Phase III (on the day of ovum pick-up) between success and unsuccess subjects; 2) compare follicular fluid (FF) adiponectin levels between success and unsuccess groups; 3) compare serum adiponectin levels among different phases of IVF/ICSI treatment in success and unsuccess groups; 4) compare the levels of adiponectin between serum and FF; and 5) investigate the effects of adiponectin on mRNA expressions of follicle stimulating hormone receptor (FSHR) and CYP19A1 (aromatase) in human granulosa-like tumor cell line (KGN) (n=3). In the human study, recruited participants (n=30) with age of 26-40 years were enrolled between April 2018 - May 2019. Blood samples were collected at Phases I, II, and III while FF samples were collected at Phase III. Adiponectin levels were comparable between success and unsuccess subjects in both serum (all phases) and FF (Phase III). Furthermore, serum adiponectin levels were comparable among Phase I, II, and III in success and unsuccess groups. In Phase III, serum adiponectin showed positive correlations with serum adiponectin in Phase I and II and serum FSH in Phase I. Interestingly, adiponectin levels in FF were significantly lower than serum at Phase III in unsuccessful pregnancies but were comparable in successful pregnancies. Moreover, FF adiponectin had a negative correlation with serum LH at Phase III in success subjects. In the KGN cell study, adiponectin had no effects on FSHR and CYP19A1 (aromatase) mRNA expression compared with control. In conclusion, high adiponectin levels in serum compared to FF might contribute to unsuccessful IVF/ICSI treatment.