Significance of oxidative stress and antioxidant capacity tests as biomarkers of premature ovarian insufficiency: A case control study

BACKGROUND Premature ovarian insufficiency (POI) is a condition that causes secondary amenorrhea owing to ovarian hypofunction at an early stage. Early follicular depletion results in intractable infertility, thereby considerably reducing the quality of life of females. Given the continuum in weakened ovarian function, progressing from incipient ovarian failure (IOF) to transitional ovarian failure and further to POI, it is necessary to develop biomarkers for predicting POI. The oxidative stress states in IOF and POI were comprehensively evaluated via oxidative stress [diacron-reactive oxygen metabolites (d-ROMs)] test and antioxidant capacity [biological antioxidant potential (BAP)]. AIM To explore the possibilities of oxidative stress and antioxidant capacity as biomarkers for the early detection of POI. METHODS Females presenting with secondary amenorrhea over 4 mo and a follicle stimulating hormone level of > 40 mIU/mL were categorized into the POI group. Females presenting with a normal menstrual cycle and a follicle stimulating hormone level of > 10.2 mIU/mL were categorized into the IOF group. Healthy females without ovarian hypofunction were categorized into the control group. Among females aged < 40 years who visited our hospital from January 2021 to June 2022, we recruited 11 patients into both POI and IOF groups. For the potential antioxidant capacity, the relative oxidative stress index (BAP/d-ROMs x 100) was calculated, and the oxidative stress defense system was comprehensively evaluated. RESULTS d-ROMs were significantly higher in the POI and IOF groups than in the control group, (478.2 +/- 58.7 U.CARR, 434.5 +/- 60.6 U.CARR, and 341.1 +/- 35.1 U.CARR, respectively) (U.CARR is equivalent to 0.08 mg/dL of hydrogen peroxide). However, no significant difference was found between the POI and IOF groups. Regarding BAP, no significant difference was found between the control, IOF, and POI groups (2078.5 +/- 157.4 mu mol/L, 2116.2 +/- 240.2 mu mol/L, and 2029.0 +/- 186.4 mu mol/L, respectively). The oxidative stress index was significantly higher in the POI and IOF groups than in the control group (23.7 +/- 3.3, 20.7 +/- 3.6, and 16.5 +/- 2.1, respectively). However, no significant difference was found between the POI and IOF groups. CONCLUSION High levels of oxidative stress suggest that evaluating the oxidative stress state may be a useful indicator for the early detection of POI.