Relationships Between a Range of Inflammatory Biomarkers and Subjective Sleep Quality in Chronic Insomnia Patients: A Clinical Study

Figures & data

Table 1 Demographic and Clinical Characteristics of Participants

Variable	CID	GS	Statistic	P-value
Number	65	39
Sex (female, n, %)	22, 58.5%	19, 51.3%	χ^2 = 0.509	0.475
Age (yr)	41.37 ± 12.12	42.15 ± 14.28	t = 0.299	0.766
Education (yr)	12.00 (9.00, 16.00)	15.00 (9.00, 16.00)	z = 0.306	0.760
PSQI (score)	14.97 ± 2.90*	2.00 (1.00, 3.00)	z = 8.539	< 0.001
AIS (score)	14.55 ± 4.11*	0.00 (0.00, 1.00)	z = 8.603	< 0.001
HAMD-17 (score)	10.40 ± 3.87*	3.00 (1.00, 5.00)	z = 8.068	< 0.001
HAMA-14 (score)	10.71 ± 5.84*	0.00 (0.00, 2.00)	z = 8.136	< 0.001

Notes: Data are expressed as mean ± SD (normally distributed variables) or P50 (P25, P75) (non-normally distributed variables). Compared to the GS group, *P < 0.05.

Abbreviations: CID, chronic insomnia disorder; GS, good sleeper; PSQI, Pittsburgh Sleep Quality Index; AIS, Athens Insomnia Scale; HAMD-17, 17-item Hamilton Depression Rating Scale; HAMA-14, 14-item Hamilton Anxiety Rating Scale.

Table 2 TNF-α, RANTES, SAA and GM-CSF Levels in Participants

Variable	CID	GS	Statistic	P-value
Number	65	39
TNF-α (pg/mL)	427.41 ± 203.60**	322.51 ± 117.74	t = 3.188	0.002
RANTES (ng/mL)	4.30 ± 0.62*	4.60 ± 0.72	t = 2.180	0.032
SAA (ng/mL)	53.50 (32.89, 72.47)**	28.31 (19.30, 38.71)	z = 4.575	< 0.001
GM-CSF (pg/mL)	152.00 ± 49.62**	113.18 ± 40.02	t = 4.142	< 0.001

Notes: Data are expressed as mean ± SD (normally distributed variables) or P50 (P25, P75) (non-normally distributed variables). Compared to the GS group, *P < 0.05, **P < 0.01.

Abbreviations: CID, chronic insomnia disorder; GS, good sleeper; TNF-α, tumor necrosis factor-α; RANTES, regulated on activation and normal T cell expressed and presumably secreted; SAA, serum amyloid protein A; GM-CSF, granulocyte-macrophage colony-stimulating factor.

Table 3 Correlations of RANTES, SAA, GM-CSF, and TNF-α with Mood

Analysis	Variable	Sex	Age	Education	PSQI	AIS	TNF-α	RANTES	SAA	GM-CSF
Spearman correlation (r)	HAMD-17	0.208*	−0.013	−0.073	0.795**	0.800**	0.256*	−0.010	0.376**	0.308**
	HAMA-14	0.235*	−0.013	−0.115	0.770**	0.847**	0.196	−0.105	0.432**	0.290**
Partial correlation (r)^a	HAMD-17						0.103	0.204	−0.066	−0.025
	HAMA-14						−0.148	−0.007	−0.023	−0.176
Stepwise linear regression (β)	HAMD-17				0.344*	0.507**
	HAMA-14					0.796**

Notes: ^aPartial correlation analysis, controlling for the factors sex, PSQI score, and AIS score. *P < 0.05, **P < 0.01.

Abbreviations: HAMD-17, 17-item Hamilton Depression Rating Scale; HAMA-14, 14-item Hamilton Anxiety Rating Scale; TNF-α, tumor necrosis factor-α; RANTES, regulated on activation and normal T cell expressed and presumably secreted; SAA, serum amyloid protein A; GM-CSF, granulocyte-macrophage colony-stimulating factor; PSQI, Pittsburgh Sleep Quality Index; AIS, Athens Insomnia Scale.

Table 4 Correlations of RANTES, SAA, GM-CSF, and TNF-α with Insomnia

Analysis	Variable	Sex	Age	Education	HAMD-17	HAMA-14	TNF-α	RANTES	SAA	GM-CSF
Spearman correlation (r)	PSQI	0.180	0.120	–0.147	0.795**	0.770**	0.184	–0.135	0.282**	0.297**
	AIS	0.238*	0.007	–0.160	0.800**	0.847**	0.169	–0.125	0.398**	0.331**
Partial correlation (r)^a	PSQI						0.118	–0.183	0.203	0.268*
	AIS						0.086	–0.202	0.282**	0.285**
Stepwise linear regression (β)	PSQI				0.536**	0.228*		–0.159**		0.184**
	AIS				0.180**	0.322**		–0.165**	0.138*	0.172**

Notes: ^aPartial correlation analysis, controlling for sex, HAMD-17 score, and HAMA-14 score. *P < 0.05; **P < 0.01.

Abbreviations: PSQI, Pittsburgh Sleep Quality Index; AIS, Athens Insomnia Scale; HAMD-17, 17-item Hamilton Depression Rating Scale; HAMA-14, 14-item Hamilton Anxiety Rating Scale; TNF-α, tumor necrosis factor-α; RANTES, regulated on activation and normal T cell expressed and presumably secreted; SAA, serum amyloid protein A; GM-CSF, granulocyte-macrophage colony stimulating factor.

Table 5 ROC Curve Analysis Results Regarding Potential Blood Biomarkers of CID

Variable	AUC (95% CI)	Cut-Off	Sensitivity	Specificity
TNF-α	≥ 0.663 (0.551–0.775)**	367.12 pg/mL	0.554	0.743
RANTES	≤ 0.624 (0.498–0.750)*	3.81 ng/mL	0.821	0.257
SAA	≥ 0.761 (0.664–0.858)**	52.09 ng/mL	0.536	0.914
GM-CSF	≥ 0.761 (0.657–0.865)**	133.46 pg/mL	0.714	0.743

Notes: *P < 0.05, **P < 0.01. Abbreviations: ROC, receiver operating characteristic; AUC, area under the curve; CID, chronic insomnia disorder; TNF-α, tumor necrosis factor-α; RANTES, regulated on activation and normal T cell expressed and presumably secreted; SAA, serum amyloid protein A; GM-CSF, granulocyte-macrophage colony stimulating factor.