
(sz) A recent study published in The Journal of Clinical Endocrinology and Metabolism, has demonstrated that low reproductive outcomes following ART in obese women may be associated with alterations in ovarian follicular environment, in particular the raised levels of C-reactive protein (CRP), metabolites, and androgen activity.
Previous studies have reported increased time to conception in obese women, although they are young and have normal menstrual cycles, thereby suggesting an alteration in the functions of ovary during the peri-conceptual period.
Rebecca Robker and coworkers from the University of Adelaide, Australia, conducted the study to determine whether changes in the pre-ovulatory follicular environment have an effect on the oocyte developmental competence in 96 women receiving infertility treatment. Based on the body mass index (BMI), the subjects were divided into 3 groups: moderate, with BMI=20 to 24.9 kg/m2 (n=33), overweight, with BMI=25 to 29.9 kg/m2 (n=31), and obese, with BMI ≥30 kg/m2 (n=32). The follicular fluid was aspirated in each patient from single follicles at oocyte retrieval followed by the pooling of the granulosa cells from the aspirates and the collection of cumulus cells after separation from the oocytes.
The researchers further analyzed the hormones and metabolites in the follicular fluid. Also, mRNA expression of insulin signaling components (IRS-2, Glut4), glucose regulated genes (ChREBP, ACC, FAS) and insulin regulated genes (SREBP-1, CD36, SR-BI) related to obesity/insulin resistance were measured in the granulosa and cumulus cells. Results showed that BMI was directly proportional to the follicular fluid insulin, lactate, triglycerides, and CRP levels, but was inversely related to sex hormone-binding globulin levels (P=0.001). Although IRS-2, Glut4, ChREBP and SREBP displayed a cell-type specific expression, they were unaffected by BMI. The scientists also noted that obese rather than moderate weight women had a modest variation in CD36 and SRBI mRNA of granulosa cells. Considering the findings, it was suggested that alterations in the ovarian follicular environment exhibited by obese women were probably linked to poor reproduction outcomes. more…
From: »IVF News.Direct!«