. 2022 Jun 14;11(6):1161. doi: 10.3390/antiox11061161

Table 3.

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 the GnRHa (D2), after hCG administration (D3), and on the day of oocyte retrieval (D4), comparing the four timepoints within each group: infertile women with endometriosis (regardless of disease staging—E), with early endometriosis (EI/II), and with advanced endometriosis (EIII/IV), and infertile controls (C).

Group	OS Marker	D1	D2	D3	D4
C (n = 60)	FOX₁	8.38 ^abc	7.76 ^a	7.71 ^b	7.66 ^c
	SOD	589.87 ^a	560.00 ^b	481.48 ^abc	564.66 ^c
	VITE	22.06	22.30	22.22	20.80
	GSH	181.90	181.26	188.28	196.83
	TAC	0.49 *	0.50	0.43 *	0.45
	AOPP	103.45^a	136.05 ^ab	124.68	115.26 ^b
	MDA	18.96 *	20.66 *^a	18.94	18.82 ^a
	8OHdG	21.27	20.23	21.45	19.38
E (n = 53)	FOX₁	8.81 ^ab	7.82 ^a	7.69 ^b	8.22
	SOD	554.82 ^a	520.69 ^b	499.93 ^c	666.69 ^abc
	VITE	22.30	22.55	23.05	23.72
	GSH	191.38 *^ab	211.13 *	222.13 ^a	220.51 ^b
	TAC	0.40 ^ab	0.39 *	0.33 ^a*	0.34 ^b
	AOPP	113.84 ^a	146.98 ^a	132.84	133.83
	MDA	19.67	19.26	18.81	19.45
	8OHdG	16.92	19.08	18.37	16.57
EI/II (n = 35)	FOX₁	8.77 *^a	8.09 *	7.72 ^a	8.38
	SOD	534.63	507.43 ^a	526.34	619.89 ^a
	VITE	21.56	22.83	21.94	23.78
	GSH	189.48 ^a	201.78	214.18	219.52 ^a
	TAC	0.40	0.44 ^ab	0.35 ^a	0.34 ^b
	AOPP	104.96 ^ab	147.19 ^a	135.23	149.88 ^b
	MDA	19.81	19.29	19.67	18.96
	8OHdG	15.81	18.53	17.06	16.05
EIII/IV (n = 18)	FOX₁	9.23 ^a	7.45 ^a	7.89	8.36
	SOD	580.07 ^a	537.15 ^b	485.83 ^c	812.78 ^abc
	VITE	22.16	22.74	23.98	23.77
	GSH	179.26 ^ab	216.25	235.45 ^a	231.82 ^b
	TAC	0.39 ^a	0.36	0.31	0.29 ^a
	AOPP	119.97	152.00	126.76	121.47
	MDA	18.99	16.63	16.43	18.00
	8OHdG	16.92	20.19	18.80	17.36

Note: GnRHa: gonadotropin-releasing hormone agonist. hCG: human chorionic gonadotropin. Data presented as mean 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 represent significant differences. *: p = 0.05.