Association of Systemic Inflammation with Depressive Symptoms in Individuals with COPD

Figures & data

Table 1 Baseline Characteristics Stratified by Depressive Symptoms

	SCCOR (N=220)			COPDGene (N=745)
	Depressive Symptoms
	Minimal	Elevated	p-value	Minimal	Elevated	p-value
N	173	47		648	97
Age, mean (SD)	67.2 (6.7)	65.5 (6.5)	0.12	69.6 (8.2)	66.7 (8.5)	0.002
Gender			0.51			0.19
Male	99 (57.2%)	24 (51.1%)		359 (55.4%)	61 (62.9%)
Female	74 (42.8%)	23 (48.9%)		289 (44.6%)	36 (37.1%)
BMI, mean (SD)	27.8 (4.2)	26.5 (3.5)	0.04	26.2 (4.0)	26.5 (4.1)	0.53
Active Smokers	66 (38.2%)	27 (57.4%)	0.02	187 (28.9%)	40 (41.2%)	0.02
BDI-II, median (IQR)	4.0 (1.0, 6.0)	14.0 (11.0, 16.0)	<0.001
HADS-D, median (IQR)	–	–		2.0 (1.0, 4.0)	9.0 (8.0, 11.0)	<0.001
FEV1/FVC, mean (SD)	58.1 (10.2)	53.8 (10.6)	0.01	53.0 (12.5)	48.3 (13.5)	0.002
FEV1pp, mean (SD)	71.2 (18.1)	66.0 (18.4)	0.09	61.8 (23.0)	52.4 (23.2)	<0.001
SGRQ, mean (SD)	21.4 (15.4)	38.1 (15.8)	<0.001	26.7 (18.5)	49.3 (20.9)	<0.001
SWD in feet, mean (SD)	394.8 (139.5)	372.7 (126.6)	0.31
6MWD in feet, mean (SD)				1254.2 (408.0)	1045.6 (396.5)	<0.001
IL-6, median (IQR)	1.3 (0.9, 2.1)	2.0 (1.0, 2.6)	0.08	1.9 (1.2, 2.8)	2.4 (1.5, 3.9)	0.001
Gold Stage			0.01			0.002
I	59 (34.1%)	8 (17.0%)		158 (24.4%)	11 (11.3%)
II	88 (50.9%)	33 (70.2%)		266 (41.0%)	39 (40.2%)
III	25 (14.5%)	4 (8.5%)		162 (25.0%)	28 (28.9%)
IV	1 (0.6%)	2 (4.3%)		62 (9.6%)	19 (19.6%)

Abbreviations: BMI, Body Mass Index; BDI-II, Beck Depression Inventory-II; HADS-D, Hospital Anxiety and Depression Score, Depression Subset; SGRQ, St. George’s Respiratory Questionnaire; SWD, Shuttle Walk Distance; 6MWD, Six Minute Walk Distance.

Table 2 The Association Between Depressive Symptoms and IL-6 Levels

	SCCOR		COPDGene
	OR (95% CI)	p-value	OR (95% CI)	p-value
Unadjusted*	1.79 (1.12–2.86)	0.014	1.60 (1.23–2.08)	<0.001
Non-pulmonary confounders^┼	1.79 (1.12–2.86)	0.014	1.61 (1.23 −2.11)	0.001
Pulmonary and non-pulmonary confounders¥	1.70 (1.07–2.68)	0.024	1.52 (1.13 −2.04)	0.006

Notes: *Adjusted for gender, age, BMI. ^┼Adjusted for gender, age, BMI, stroke, diabetes, cancer history; diabetes not included for SCCOR. ^¥Adjusted for gender, age, BMI, stroke, diabetes, cancer history, smoking status, FEV₁/FVC; diabetes not included for SCCOR.