Study On The Serum And Follicular Fluid Alterations Of Inhibin B And Insulin Like Growth Factor I And Relevant Factors In Patients With Polycystic Ovary Syndrome

Objective To investigate serum and follicular fluid alterations of inhibin B andinsulin like growth factor I and relevant factors in patients with polycystic ovary syndrome and regularly cycling women.Methods The present study was based on two separate studies.In the first(serum)study, Serum were collected from 47 patients with pcos and another 26 control women with regular menses in the day 3 of the menstrual cycle. Serum inhibin B and insulin like growth factor I were assayed by enzyme-linked immunosorbent assays. Serum FSH, LH, PRL, E2, T, DHEAS, fasting insulin,c-peptide and glucose were also assayed at the same time .Correlation analysis were applied to serum inhibin B and insulin like growth factor I and age, body mass index, sex hormone, serum fasting insulin, c-peptide, glucose , HOMA-IR. In addition, a second(follicular fluid and peripheral serum) study inhibin B and insulin like growth factor I, E2, T were assayed in the follicular fluid of 10mm follicles from 11 PCOS patients and size-matched follicles from 11 normally cycling women. Peripheral serum were collected and assayed at the same time. Comparasion and correlation analysis of follicular fluid and peripheral serum hormone levels were also conducted.Results In the first study, mean serum inhibin B level was markedly increased in the PCOS group;but there was no difference in IGF-I level between PCOS and control women. Simple regression analysis showed that in PCOS, serum inhibin B level was negatively related to BMI and insulin, but positively related to the LH, T, IGF-Ilevels and LH/FSH; serum IGF-I level was positively related to INHB, insulin and HOMA-IR; After correction for BMI, there were still positive relationship between inhibin B and LH, T, IGF-I; IGF-I and HOMA-IR, insulin. After multiple regression inhibin B was affected by T and BMI ;IGF-I was affected by HOMA-IR. In the second study, we found that PCOS was associated with increased inhibin B, IGF-I and T concentrations in follicular fluid, but there was no difference in E2 concentrations . In both control and polycystic ovaries, follicular fluid concentrations of inhibin B, E2, T were much higher than those found in serum. There was no difference in IGF-I concentrations between follicular fluid and serum levels. Further, there were significant and positive correlations between the follicular fluid levels of inhibin B and IGF-I, inhibin B and T, IGF-I and T in the PCOS women ;only inhibin B and IGF-I ,inhibin B and T were found correlated in the control subjects.Conclusions In women with PCOS, serum and follicular fluid inhibin B concentrations were higher than those found in control women, inhibin B was higher in follicular fluid than in serum level, and intrafollicular and serum inhibin B were significantly correlated to T concentrations. These data support the concept that PCOS is associated with a dysfuction in the endocrine and autocrine and/or paracrine regulation. Obesity has an independent effect on inhibin B concentrations. Follicular fluid IGF-I concentrations was not different from that in the serum level in both group. Serum IGF-I concentrations in PCOS was not different from that in the control women, but it was higher in follicular fluid in the PCOS women, IGF-I in the micro-environment may play a role in the pathophysiology of PCOS .