Table 2.
Oxidative stress (OS) markers in serum samples obtained during the early follicular phase of the natural cycle prior to the beginning of controlled ovarian stimulation for ICSI (D1), after pituitary downregulation with GnRHa (D2), after hCG administration (D3), and on the day of oocyte retrieval (D4), comparing infertile women with endometriosis (regardless of disease staging—E), with early endometriosis (EI/II), and with advanced endometriosis (EIII/IV) and infertile controls (C).
| Time-Point | OS Marker | C (n = 60) |
E (n = 53) |
EI/II (n = 35) |
EIII/IV (n = 18) |
|---|---|---|---|---|---|
| D1 | FOX1 | 8.38 (7.85–8.92) | 8.81 (8.32–9.30) | 8.77 (8.18–9.36) | 9.23 (8.00–10.46) |
| SOD | 589.87 (516.44–663.30) | 554.82 (511.10–598.54) | 534.63 (488.73–580.53) | 580.07 (479.07–681.07) | |
| VitE | 22.06 (20.50–23.63) | 22.3 (20.41–24.19) | 21.56 (19.28–23.84) | 22.16 (17.96–26.36) | |
| GSH | 181.91 (167.15–196.67) a | 191.38 (175.29–207.46) | 189.48 (170.37–208.60) ab | 179.26 (142.81–215.70) b | |
| TAC | 0.49 (0.45–0.53) abc | 0.40 (0.34–0.45) a | 0.40 (0.33–0.46) b | 0.39 (0.30–0.48) c | |
| AOPP | 103.45 (87.59–119.32) | 113.84 (100.12–127.55) | 104.96 (89.29–120.62) | 119.97 (92.81–147.14) | |
| MDA | 18.96 (15.85–22.07) | 19.67 (17.17–22.17) | 19.81 (16.18–23.45) | 18.99 (14.14–23.84) | |
| 8OHdG | 21.27 (19.06–23.49) abc | 16.92 (15.12–18.73) a | 15.81 (14.18–17.44) b | 16.92 (11.67–22.18) c | |
| D2 | FOX1 | 7.76 (7.30–8.22) | 7.82 (7.45–8.19) | 8.09 (7.56–8.63) | 7.45 (6.70–8.19) |
| SOD | 560.0 (499.45–620.55) | 520.69 (485.0–556.39) | 507.43 (454.01–560.85) | 537.15 (467.85–606.45) | |
| VitE | 21.4 (19.62–23.18) | 22.55 (20.96–24.14) | 22.83 (20.47–25.19) | 22.74 (19.19–26.29) | |
| GSH | 181.26 (168.74–193.78) a* | 211.13 (199.29–222.96) a | 201.78 (183.82–219.74) | 216.25 (198.29–234.20) * | |
| TAC | 0.50 (0.46–0.53) ab | 0.39 (0.33–0.46) a | 0.44 (0.35–0.53) c | 0.36 (0.23–0.49) bc | |
| AOPP | 136.05 (115.39–156.70) | 146.98 (126.49–167.46) | 146.19 (117.38–177.01) | 152.00 (110.92–193.08) | |
| MDA | 20.66 (16.95–24.38) | 19.26 (16.01–22.50) | 19.29 (14.77–23.82) | 16.63 (10.27–23.00) | |
| 8OHdG | 20.23 (18.25–22.20) | 19.08 (16.66–21.49) | 18.53 (15.59–21.48) | 20.19 (14.28–26.09) | |
| D3 | FOX1 | 7.71 (7.12–8.29) | 7.69 (7.32–8.06) | 7.72 (7.16–8.27) | 7.89 (7.11–8.67) |
| SOD | 481.48 (431.22–531.75) | 499.93 (433.49–566.37) | 526.34 (453.26–599.42) | 485.83 (305.34–666.32) | |
| VitE | 22.22 (19.93–24.51) | 23.05 (20.92–25.17) | 21.94 (19.23–24.66) | 23.98 (19.0–28.97) | |
| GSH | 188.28 (176.88–199.69) ab* | 222.13 (212.58–231.68) a | 214.18 (200.72–227.64) * | 235.45 (217.51–253.38) b | |
| TAC | 0.43 (0.40–0.47) ab | 0.33 (0.27–0.39) a | 0.35 (0.27–0.42) | 0.31 (0.19–0.43) b | |
| AOPP | 124.68 (103-57–145.79) | 132.84 (112.28–153.40) | 135.23 (104.30–166.15) | 126.76 (89.23–164.30) | |
| MDA | 18.94 (15.37–22.51) | 18.81 (15.73–21.88) | 19.67 (15.68–23.65) | 16.43 (9.69–23.18) | |
| 8OHdG | 21.45 (19.19–23.70) ab | 18.37 (16.21–20.53) a | 17.06 (14.33–19.79) b | 18.80 (14.98–22.62) | |
| D4 | FOX1 | 7.66 (7.15–8.17) a* | 8.22 (7.72–8.72) * | 8.38 (7.61–9.14) | 8.36 (7.61–9.12) a |
| SOD | 564.66 (511.83–617.49) ab | 666.69 (576.13–757.25) a | 619.89 (492.77–747.01) c | 812.78 (651.02–974.55) bc | |
| VitE | 20.80 (18.62–22.97) | 23.72 (21.52–25.92) | 23.78 (21.17–26.39) | 23.77 (18.66–28.89) | |
| GSH | 196.83 (184.12–209.55) * | 220.51 (207.54–233.49) * | 219.52 (200.91–238.12) | 231.82 (210.38–253.27) | |
| TAC | 0.45 (0.41–0.50) abc | 0.34 (0.29–0.39) a | 0.34 (0.27–0.42) b | 0.29 (0.20–0.37) c | |
| AOPP | 115.26 (96.23–134.29) a | 133.83 (112.16–155.51) | 149.88 (117.60–182.17) a | 121.47 (84.67–158.28) | |
| MDA | 18.82 (15.5–22.14) | 19.45 (15.64–23.27) | 18.96 (13.51–24.41) | 18.0 (11.62–24–37) | |
| 8OHdG | 19.38 (17.35–21.40) | 16.57 (15.30–17.85) | 16.05 (14.58–17.52) | 17.36 (14.28–10.44) |
Note: Data presented as mean (95% Confidence Interval) and compared among groups using a linear regression mixed-effects model and an orthogonal contrast post-test. Significance was defined as p-value < 0.05. FOX1 (total hydroperoxides): μmol/g protein; MDA (malondialdehyde): nmol/g protein; AOPP (advanced oxidation protein products): μmol/L; 8OHdG (8-hydroxy-2′-deoxyguanosine): ng/mL; GSH (reduced glutathione): nmol/g protein, VitE (vitamin E): μmol/L; SOD (superoxide dismutase): U/mL; TAC (total antioxidant capacity): mEq Trolox/L. The same superscript letters in a line indicate a significant difference. *: p = 0.05.