Gender Differences of Antioxidant System and Thyroid Function in Depressed Adolescents with Non-Suicidal Self-Injury

Figures & data

Table 1 Demographic and Clinical Characteristics of the Participants

Characteristics	Before PSM				After PSM
	MDD/NSSI (n=239) N (%) Median (IQR) Mean ± SD	MDD/non-NSSI (n=215) N (%) Median (IQR) Mean ± SD	Statistic	P	MDD/NSSI (n=158) N (%) Median (IQR) Mean ± SD	MDD/non-NSSI (n=158) N (%) Median (IQR) Mean ± SD	Statistic	P
Gender (% female)	197 (82.43)	148 (68.84)	χ²=11.457	0.001^b	128 (81.01)	113 (71.52)	χ²=3.934	0.047^b
Age	15 (14–16)	16 (15–17)	z=−6.239	<0.001^a	16 (14–16)	15 (14–16)	z=−1.238	0.216^a
BMI	20.00 (18.21–21.98)	20.30 (18.73–22.40)	z=−1.310	0.190^a	20.15 (18.39–21.90)	20.30 (18.73–22.63)	z=−0.781	0.435^a
Smoking	18 (7.53)	16 (7.44)	χ²=0.001	0.971^b	12 (7.59)	7(4.43)	χ²=1.400	0.237^b
Family history of mental illness	29 (12.13)	22 (10.28)	χ²=0.388	0.533^b	19 (12.03)	17 (10.83)	χ²=0.112	0.738^b
Age of onset	13 (12–15)	14 (13–15)	z=−3.845	<0.001^a	14 (12.75–15)	14 (13–15)	z=−1.016	0.309^a
Duration of illness (months)	12 (6–24)	12 (6–26)	z=−1.145	0.252^a	12 (7–24)	12 (6–24)	z=−0.415	0.678^a
Antidepressant use	150 (62.76)	98 (44.79)	χ²=13.120	<0.001^b	108 (68.35)	69 (43.95)	χ²=19.054	<0.001^b
PHQ-9 (scores)	21 (17–24)	18 (14–22)	z=−5.806	<0.001^a	20 (17–23.25)	18 (14–22)	z=−5.009	<0.001^a
GAD-7 (scores)	16 (12–18)	14 (9–18)	z=−3.002	0.003^a	16 (12–18)	13 (9–18)	z=−2.538	0.011^a
Tbil (μM)	8.43 (6.24–11.57)	9.66 (7.03–12.60)	z=−3.211	0.001^a	8.70 (6.67–11.87)	9.53 (7.03–12.56)	z=−1.999	0.046^a
UA (μM)	312.12 (265.57–377.12)	336.11 (288.40–390.66)	z=−3.137	0.002^a	312.75 (265.96–380.18)	328.46 (283.62–383.33)	z=−2.422	0.015^a
FT3 (p M)	4.86±0.75	4.90±0.76	t=−0.415	0.678^c	4.76±0.72	4.90±0.76	t=−1.575	0.116^c
FT4 (p M)	14.91 (13.49–16.52)	15.47 (14.04–17.08)	z=−2.277	0.023^a	15.03±2.47	15.39±2.27	t=−1.247	0.213^a
TSH (μ IU/mL)	1.80 (1.24–2.60)	1.90 (1.25–2.83)	z=−0.719	0.472^a	1.79 (1.30–2.67)	1.90 (1.26–2.85)	z=−0.814	0.416^a

Notes: ^aMedian (interquartile range). Mann–Whitney Test. ^bNumber (percentage). Level of significance of the chi-squared test. ^cMean ± s.d. Two independent samples t-test.

Abbreviations: PSM, propensity score method; MDD/non-NSSI=Major depressive disorder without non-suicidal self-injury group; MDD/NSSI=Major depressive disorder with non-suicidal self-injury; IQR=inter quartile range; BMI, body mass index; PHQ-9, 9-item Patient Health Questionnaire; GAD-7, 7-item Generalized Anxiety Disorder scale; Tbil, total bilirubin; UA, uric acid; FT3, free triiodothyronine; FT4, free thyroxine; TSH, thyroid-stimulating hormone.

Figure 1 The selection process for this study.

Table 2 Binary Logistic Regression of Related Factors of NSSI in Female MDD Patients

Factor	B^a	Wald^a	OR^a	95% CI^a	P	B^b	Wald^b	OR^b	95% CI^b	P
Tbil	−0.023	0.028	0.978	0.925–1.033	0.423	0.007	0.052	1.007	0.948–1.070	0.819
UA	−0.004	4.850	0.996	0.992–1.000	0.028	−0.005	6.026	0.995	0.991–0.999	0.014
FT3	−0.250	1.644	0.778	0.531–1.142	0.200	−0.085	0.159	0.919	0.606–1.393	0.690
FT4	−0.047	0.616	0.954	0.847–1.074	0.432	0.020	0.084	1.020	0.891–1.168	0.773
TSH	−0.012	0.011	0.915	0.800–1.221	0.915	0.034	0.080	1.034	0.820–1.303	0.777

Notes: ^aUncorrected. ^bCorrected the difference factors, including: antidepressant use, PHQ-9 and GAD-7.

Abbreviations: Tbil, total bilirubin; UA, uric acid; FT3, free triiodothyronine; FT4, free thyroxine; TSH, thyroid-stimulating hormone.

Table 3 Binary Logistic Regression of Related Factors of NSSI in Male MDD Patients

Factor	B	Wald	OR	95% CI	P
Tbil	−0.009	0.068	0.991	0.926–1.060	0.794
UA	0.001	0.133	1.001	0.996–1.006	0.715
FT3	−0.103	0.073	0.902	0.426–1.908	0.787
FT4	−0.071	0.428	0.932	0.754–1.152	0.513
TSH	−0.695	4.749	0.499	0.267–0.932	0.029

Abbreviations: Tbil, total bilirubin; UA, uric acid; FT3, free triiodothyronine; FT4, free thyroxine; TSH, thyroid-stimulating hormone.

Data Sharing Statement

All data generated or analyzed during this study are included in this article. Further enquiries can be directed to the corresponding author.