Impact of post-stroke depression on the prognosis of stroke-associated pneumonia and analysis of predictive factors: A retrospective study of 186 patients

Table 1 Demographic and clinical characteristics of study participants, mean ± SD or n (%)

Characteristic	Depression group (n = 92)	Non-depression group (n = 94)	P value
Age (year)	66.5 ± 10.8	64.2 ± 11.5	0.162
Female	54 (58.7)	34 (36.2)	0.002
BMI (kg/m2)	23.8 ± 3.5	24.2 ± 3.1	0.428
Education level			0.285
Primary or below	38 (41.3)	32 (34.0)
Secondary	35 (38.0)	40 (42.6)
College or above	19 (20.7)	22 (23.4)
Smoking	25 (27.2)	28 (29.8)	0.688
Alcohol use	18 (19.6)	16 (17.0)	0.649
Comorbidities
Hypertension	58 (63.0)	55 (58.5)	0.525
Diabetes mellitus	28 (30.4)	24 (25.5)	0.453
COPD	15 (16.3)	12 (12.8)	0.489
Coronary heart disease	14 (15.2)	11 (11.7)	0.475
Chronic kidney disease	8 (8.7)	6 (6.4)	0.546
Previous stroke	18 (19.6)	14 (14.9)	0.393
NIHSS at admission	10.2 ± 3.5	7.1 ± 2.8	< 0.001
GCS score	11.5 ± 2.2	13.2 ± 1.8	< 0.001
Dysphagia	68 (73.9)	52 (55.3)	0.008
SSRS score	29.5 ± 8.2	38.8 ± 7.5	< 0.001
NRS-2002 ≥ 3	62 (67.4)	45 (47.9)	0.007

BMI: Body mass index; COPD: Chronic obstructive pulmonary disease; NIHSS: National Institutes of Health Stroke Scale; GCS: Glasgow Coma Scale; SSRS: Social Support Rating Scale; NRS-2002: Nutritional Risk Screening 2002.

Table 2 Stroke-associated pneumonia clinical features and severity, mean ± SD or n (%)

SAP feature	Depression group (n = 92)	Non-depression group (n = 94)	P value
Onset to SAP (days)	3.2 ± 1.5	3.5 ± 1.8	0.226
APACHE II score	17.8 ± 4.5	13.2 ± 3.8	< 0.001
CURB-65 score	2.8 ± 0.9	2.1 ± 0.8	< 0.001
Pathogen distribution
Gram-negative bacilli	52 (56.5)	48 (51.1)	0.453
Gram-positive cocci	22 (23.9)	25 (26.6)	0.668
Fungi	12 (13.0)	8 (8.5)	0.323
Mixed infection	18 (19.6)	15 (16.0)	0.514
MDR organism	35 (38.0)	21 (22.3)	0.019
Bilateral involvement	48 (52.2)	33 (35.1)	0.019
Pleural effusion	26 (28.3)	14 (14.9)	0.026
Mechanical ventilation	60 (65.2)	40 (42.6)	0.002
MV duration (days)	8.5 ± 3.2	5.2 ± 2.1	< 0.001
ICU admission	55 (59.8)	38 (40.4)	0.008
ICU stay (days)	12.5 ± 4.8	8.2 ± 3.5	< 0.001
Tracheostomy	18 (19.6)	8 (8.5)	0.028

SAP: Stroke-associated pneumonia; APACHE II: Acute Physiology and Chronic Health Evaluation II; MDR: Multi-drug resistant; MV: Mechanical ventilation; ICU: Intensive care unit.

Table 3 Treatment modalities and prognostic outcomes, mean ± SD or n (%)

Outcome measure	Depression group (n = 92)	Non-depression group (n = 94)	P value
Treatment
Antibiotics duration (days)	14.2 ± 4.5	10.5 ± 3.2	< 0.001
Corticosteroid use	28 (30.4)	18 (19.1)	0.072
Warm moxibustion	35 (38.0)	43 (45.7)	0.291
Early enteral nutrition	55 (59.8)	68 (72.3)	0.068
Antidepressant treatment	45 (48.9)	-	-
Prognostic outcomes
Infection resolution (days)	16.8 ± 4.5	11.2 ± 3.2	< 0.001
Hospital stays (days)	28.5 ± 7.8	19.3 ± 5.6	< 0.001
28-day mortality	17 (18.5)	7 (7.4)	0.024
mRS ≥ 3 at discharge	67 (72.8)	46 (48.9)	0.001
mRS ≥ 4 at discharge	42 (45.7)	22 (23.4)	0.001
Barthel Index at discharge	48.2 ± 18.5	65.8 ± 14.2	< 0.001
Readmission within 30 days	22 (23.9)	10 (10.6)	0.015
Composite adverse outcome	52 (56.5)	26 (27.7)	< 0.001

Composite adverse outcome defined as 28-day mortality, infection resolution >21 days, mechanical ventilation >14 days, or modified Rankin Scale ≥ 4 at discharge. mRS: Modified Rankin Scale.

Table 4 Laboratory biomarkers in depression and non-depression groups (day 7), mean ± SD

Biomarker	Depression group (n = 92)	Non-depression group (n = 94)	P value
Infection markers
PCT (ng/mL)	2.85 ± 1.32	1.52 ± 0.85	< 0.001
CRP (mg/L)	85.6 ± 28.5	52.3 ± 18.6	< 0.001
WBC (× 109/L)	13.8 ± 4.2	11.2 ± 3.5	0.001
Inflammatory cytokines
IL-6 (pg/mL)	42.5 ± 12.8	25.8 ± 8.5	< 0.001
TNF-α (pg/mL)	28.5 ± 8.2	18.2 ± 5.8	< 0.001
IL-10 (pg/mL)	8.5 ± 2.8	12.2 ± 3.5	< 0.001
Neurotrophic factor
BDNF (ng/mL)	11.8 ± 4.2	21.5 ± 6.8	< 0.001
Neuroendocrine
Morning cortisol (nmol/L)	408.5 ± 105.2	325.8 ± 78.5	< 0.001
Immune function
Lymphocyte (× 109/L)	0.95 ± 0.32	1.35 ± 0.42	< 0.001
CD4+ T cells (cells/μL)	285 ± 78	425 ± 95	< 0.001
CD4/CD8 ratio	1.05 ± 0.35	1.52 ± 0.42	< 0.001
Nutritional markers
Albumin (g/L)	28.5 ± 4.8	34.2 ± 5.2	< 0.001
Prealbumin (mg/L)	125 ± 35	185 ± 42	< 0.001
Transferrin (g/L)	1.52 ± 0.38	1.95 ± 0.45	< 0.001
Metabolic
HbA1c (%)	7.2 ± 1.5	6.5 ± 1.2	0.028
Fasting glucose (mmol/L)	8.5 ± 2.2	7.2 ± 1.8	0.012

PCT: Procalcitonin; CRP: C-reactive protein; WBC: White blood cell; IL-6: Interleukin-6; TNF-α: Tumor necrosis factor-alpha; IL-10: Interleukin-10; BDNF: Brain-derived neurotrophic factor; HbA1c: Glycated hemoglobin.

Table 5 Independent predictors of adverse prognosis: Multivariable logistic regression

Variable	β	SE	Wald	OR (95%CI)	P value
APACHE II ≥ 18	1.238	0.302	16.82	3.45 (1.92-6.20)	< 0.001
Comorbid PSD	1.138	0.268	18.02	3.12 (1.85-5.26)	< 0.001
Albumin < 30 g/L	1.022	0.298	11.76	2.78 (1.55-4.98)	0.001
MV > 7 days	0.975	0.298	10.70	2.65 (1.48-4.75)	0.001
MDR organism	0.925	0.292	10.04	2.52 (1.42-4.47)	0.002
BDNF < 14.5 ng/mL	0.855	0.312	7.51	2.35 (1.28-4.32)	0.006
Age ≥ 75 years	0.683	0.278	6.03	1.98 (1.15-3.41)	0.014
Non-significant variables
IL-6 > 35 pg/mL	0.585	0.305	3.68	1.80 (0.99-3.26)	0.055
Cortisol > 380 nmol/L	0.498	0.298	2.79	1.65 (0.92-2.95)	0.095
NIHSS ≥ 10	0.455	0.285	2.55	1.58 (0.90-2.76)	0.110
Dysphagia	0.412	0.275	2.25	1.51 (0.88-2.58)	0.134
Diabetes mellitus	0.365	0.268	1.85	1.44 (0.85-2.43)	0.174
Corticosteroid use	0.328	0.302	1.18	1.39 (0.77-2.51)	0.278

Hosmer-Lemeshow test: χ² = 5.68, P = 0.682. OR: Odds ratio; 95%CI: 95% confidence interval; APACHE II: Acute Physiology and Chronic Health Evaluation II; PSD: Post-stroke depression; MV: Mechanical ventilation; MDR: Multi-drug resistant; BDNF: Brain-derived neurotrophic factor; IL-6: Interleukin-6; NIHSS: National Institutes of Health Stroke Scale.

Table 6 Clinical outcomes stratified by depression severity, mean ± SD

Characteristic	Mild (n = 42)	Moderate (n = 33)	Severe (n = 17)	P trend
HAMD-17 score	11.5 ± 2.5	19.8 ± 1.9	27.5 ± 3.2	< 0.001
Infection resolution (days)	14.2 ± 3.8	17.5 ± 4.2	20.5 ± 5.2	< 0.001
Hospital stays (days)	25.2 ± 6.5	29.8 ± 7.5	34.5 ± 9.2	< 0.001
MV duration (days)	6.8 ± 2.5	9.2 ± 3.0	11.5 ± 4.2	< 0.001
28-day mortality (%)	11.9	18.2	29.4	0.012
mRS ≥ 3 at discharge (%)	61.9	78.8	88.2	0.005
mRS ≥ 4 at discharge (%)	33.3	51.5	64.7	0.003
Barthel Index at discharge	55.2 ± 15.8	45.5 ± 18.2	35.8 ± 20.5	< 0.001
Composite adverse outcome (%)	42.9	60.6	82.4	< 0.001
Biomarkers (day 7)
BDNF (ng/mL)	14.5 ± 3.8	10.8 ± 3.5	7.8 ± 2.8	< 0.001
IL-6 (pg/mL)	35.2 ± 10.5	45.8 ± 12.2	52.8 ± 15.5	< 0.001
PCT (ng/mL)	2.25 ± 1.05	3.05 ± 1.35	3.85 ± 1.68	< 0.001
Cortisol (nmol/L)	378 ± 92	418 ± 105	462 ± 125	0.005
Lymphocyte (× 109/L)	1.08 ± 0.35	0.88 ± 0.28	0.72 ± 0.25	< 0.001
Albumin (g/L)	30.5 ± 4.2	27.8 ± 4.5	25.2 ± 5.5	0.002

P trend values were calculated using the Jonckheere-Terpstra test for ordered alternatives. HAMD-17: Hamilton Depression Rating Scale; MV: Mechanical ventilation; mRS: Modified Rankin Scale; BDNF: Brain-derived neurotrophic factor; IL-6: Interleukin-6; PCT: Procalcitonin.