The level of IL-6 was associated with sleep disturbances in patients with major depressive disorder

Figures & data

Table 1 Demographic and clinical characteristics of 98 participants

Characteristics	MDD patients	HC	P
		(n = 44)	(n = 54)
Males (n)	20	19	0.407
Age (yesrs)	29.27±10.83	29.67±10.29	0.855
Education year	13.11±3.05	14.80±3.84	0.02
BMI	20.73±3.06	21.63±3.18	0.158
Age of onset (years)	27.35±10.67	-	-
Number of episode	1.79±2.21	-	-
Disease duration (months)	50.7±64.80	-	-
Duration the current episode (months)	4.88±5.01	-	-
HAMA total scores	14.44±6.88	-	-
HAMD17 total scores	22.60±4.93	-	-
Anxiety/somatization (scores)	4.65±1.63	-	-
Weight (scores)	1.16±0.90	-	-
Cognitive disturbance (scores)	2.44±1.61	-	-
Retardation (scores)	3.58±1.50	-	-
Sleep disturbance (scores)	6.70±2.64	-	-

Notes: Data presented as mean ± standard deviation unless otherwise stated. Anxiety/somatization, HAMD 10, 11, 12, 15, 17; Weight, HAMD 16; Cognitive disturbance, HAMD 2, 3, 9; Retardation, HAMD 1, 7, 8, 14; Sleep disturbance, HAMD 4, 5, 6.

Abbreviations: MDD, major depressive disorder; HC, healthy control; BMI, body mass index; HAMA, Hamilton Anxiety Rating Scale; HAMD, Hamilton Depression Rating Scale.

Table 2 The median of five cytokines concentration in patients with MDD and healthy controls

Cytokine (pg/ml)	MDD patients (n=44)	HC (n=54)	Z	P
IL-1β	1.73	1.59	-0.87	0.627
IL-6	1.09	0.82	-2.113	0.031^a
TNF-α	7.05	6.21	-0.802	0.178
IFN-α2	5.2	3.62	-0.859	0.347
IFN-γ	12.94	9.87	-0.866	0.169

Notes: ^aP<0.05.

Abbreviations: MDD: Major Depressive Disorder; HC: Healthy control; IL, interleukin; TNF, tumor necrosis factor; IFN, interferon.

Table 3 Relationship between cytokine concentrations and the five syndrome scores

Cytokine	Anxiety/somatization		Weight		Cognitive disturbance		Retardation		Sleep disturbance
	r	P	r	P	r	P	r	P	r	P
IL-1β	-0.111	0.477	-0.108	0.491	0.034	0.828	0.186	0.233	0.069	0.662
IL-6	-0.15	0.337	0.024	0.877	0.095	0.543	0.038	0.811	0.329	0.031^a
TNFα	-0.164	0.293	0.071	0.651	0.115	0.464	0.108	0.492	0.184	0.237
IFN-α2	-0.011	0.944	-2.1	0.177	-0.22	0.89	0.344	0.024^a	0.118	0.451
IFN-γ	-0.077	0.624	0.081	0.606	0.029	0.853	-0.069	0.658	0.054	0.73

Notes: ^aP<0.05; r, Spearman correlation coefficient.

Abbreviations: IL, interleukin; TNF, tumor necrosis factor; IFN, interferon.