HDL functionality in follicular fluid in normal-weight and obese women undergoing assisted reproductive treatment

High-density lipoproteins (HDL) exert pleiotropic roles in follicular fluid (FF). Previous studies have reported a relationship between obesity, infertility, and systemic oxidative stress. The aim of our study was to investigate for the first time the HDL functional properties in FF in obesity.

In this observational study, overweight/obese (n = 20) and normal-weight women (n = 38) undergoing assisted reproductive technology were included. Compositional properties and biochemical marker of functionality (HDL oxidation rate), HDL-associated antioxidants (paraoxonase-1 activities and CoQ10 content), and lipid hydroperoxide levels were evaluated in FF from normal-weight and overweight/obese women. Correlations between biochemical parameters and indices for oocyte and embryo quality were studied.

FF-HDL obtained from overweight/obese women are characterized by high intrinsic ability to be oxidized compared with FF-HDL from normal-weight women. These alterations are associated with lower activities of paraoxonase-1 (PON1), higher levels of lipid peroxidation, and a lower total antioxidant capacity in FF. Moreover, an association between PON1 activity and FF-HDL oxidation and clinical parameter of oocyte quality was observed.

Our data suggest that the quality of FF-HDL is important determinant for oocyte quality. Therefore, targeting FF-HDL functionality, in addition to FF-HDL-C levels, may represent a promising and interesting biomarker for reproductive outcomes.