Oxidative stress markers cannot be used as endometriosis biomarkers in infertile patients

Figures & data

Table 1. Clinical characteristics of the patients enrolled in this study.

Parameter	Units	Detail	Controls	Endometriosis	p-Value
Patient number	n	—	29	57	–
Mean age	years	—	30.2 ± 3.5	30.0 ± 2.4	>0.05
Mean body mass index	kg/m^2	—	23.3 ± 1.9	22.6 ± 2.3	>0.05
Menstrual phase	n (%)	Follicular	15 (51.7)	30 (52.6)	>0.05
		Luteal	14 (48.3)	27 (47.4)
Oral contraceptives	n (%)	No	29 (100)	57 (100)
(last 3 months)		Yes	0 (0)	0 (0)
Hormonal therapy	n (%)	No	29 (100)	57 (100)
(last 3 months)		Yes	0 (0)	0 (0)
Medications, dietary supplements	n (%)	No	29 (100)	57 (0)
(last 1 week)		Yes	0 (0)	0 (0)
Smoking status	n (%)	Non-smoker	22 (75.8)	47 (82.5)
		Smoker	5 (17.2)	5 (8.8)
		Occasional smoker	2 (7)	1 (1.7)
		Former smoker	0 (0)	4 (7)
Endometriosis	n (%)	Ovarian	0 (0)	15 (26.3)
		Peritoneal	0 (0)	16 (28.1)
		Ovarian plus peritoneal	0 (0)	22 (38.6)
		Deep infiltrating	0 (0)	4 (7)
Revised American	n (%)	I	0 (0)	20 (35)
Fertility Society score		II	0 (0)	3 (5.4)
		III	0 (0)	30 (52.6)
		IV	0 (0)	4 (7)

Figure 1. Levels of superoxide dismutase (SOD), glutathione peroxidase (GPX), serum and peritoneal hexanoyl lysine (HEL) in endometriosis patients (n = 57) and controls (n = 29).

Figure 2. ROC plot of GPX, SOD, serum HEL, and peritoneal fluid HEL.

Table 2. Values of oxidative stress markers in endometriosis patients (n = 57) and disease-free controls (n = 29).

		Median	Std. Deviation	Minimum	Maximum	P value
GPX (U/l)	Endometriosis	1.27	0.23	0.73	1.75	0.623
	Control	1.27	0.37	0.66	2.26
SOD (kU/l)	Endometriosis	41.25	8.99	22.80	69.20	0.122
	Control	38.20	6.4	28.70	53.30
Serum HEL (nmol/l)	Endometriosis	163.94	108.75	22.88	643.22	0.562
	Control	158.22	74.56	12.432	334.264
Peritoneal fluid HEL (nmol/l)	endometriosis	36.67	40.39	0	151.89	0.329
	control	45.93	27.67	2.71	106.86

Glutathione peroxidase (GPX), superoxide dismutase (SOD), hexanoyl lysine (HEL).

Table 3. Area under the curve the selected biomarker candidates.

Test result variable(s)	Area	Std. Error	Asymptotic sig.	Asymptotic 95% Confidence Interval
				Lower bound	Upper bound
GPX	0.519	0.079	0.800	0.365	0.673
SOD	0.538	0.075	0.613	0.392	0.685
Serum HEL	0.579	0.073	0.295	0.436	0.723
Peritoneal fluid HEL	0.426	0.073	0.329	0.284	0.568

Data availability statement

The datasets used and/or analyzed during the current study are available from the corresponding author upon reasonable request.