Fertility challenges: Interplay between visfatin and silent information regulator 1 (SIRT1); A cross-sectional study

Maintenance of a normal redox balance is essential for optimal ovarian function and fertility. Reduction in silent information regulator1 (SIRT1) can potentiate inflammatory pathways, mitochondrial dysfunction and ultimately programmed cell death via "hypothalamic-pituitary-ovarian axis", developing 'low-grade oocytes', potentiating obesity related problems. Current hypothesis that a reduction in antioxidant levels (measured by SIRT1, visfatin, Manganese Superoxide dismutase (MnSOD), and Glutathione reductase (GR) with increased BMI is associated with decreased fertility.

The study aimed to evaluate the relationship between obesity and OS markers and to compare their levels between fertile and infertile women, thereby elucidating the potential role of redox imbalance in obesity-associated subfertility.

A cross-sectional study comprised of 207 fertile and 135 infertile females were recruited. Body mass index (BMI) determines obesity with the formula: weight in kilograms (kg)/height in meters (m²). Women's stratification was according to the South-Asian criteria (normal=18-22; overweight =23-24; obese >25 kg/m²). The enzyme-linked immunosorbent assay (ELISA) kits measured serum levels of MnSOD, GR, visfatin and SIRT1. Pearson chi-square and ANOVA were used; study variable association was calculated by Spearman's correlation, where p<0.05 was significant.

The mean BMI was 25.94 ± 5.1 kg/m²; normal weight females were 27.5%, overweight 22.8% and obese 40.9% and infertile females had significantly increased BMI (p<0.001). The antioxidant levels of MnSOD, GR, SIRT1 and visfatin were significantly lower in infertile females (p value =0.049, 0.027, 0.027 and 0.034, respectively). Infertile women had decreased MnSOD and visfatin, decreasing from normal weight to obese (p=0.00 and 0.04). BMI was inversely related to SIRT1 and studied antioxidant concentrations.

Continuous reduction in antioxidant levels in association with increased BMI indicates that obesity contributes to oxidative stress attributed by reducing antioxidant levels, which may lead to female infertility.