Increased thoracic fluid content is associated with higher risk for pneumonia in patients undergoing maintenance hemodialysis

Figures & data

Figure 1. Flow chart of patient inclusion and grouping in this study.

Table 1. Baseline characteristics of the patients in this study.

Characteristics	Having-pneumonia group (n = 177)	Will-Have-pneumonia group (n = 101)	Non-pneumonia group (n = 1134)	p Value
Age (years)	62.07 (14.03)	57.45 (14.94)	51.99 (13.06)	0.025^a, <0.001^b, <0.001^c
Sex, male	110 (62.1)	58 (57.4)	623 (54.9)	0.190
BMI (kg/m^2)	21.90 (19.13, 24.29)	22.01 (19.37, 24.98)	22.06 (20.00, 24.16)	0.732
Dialysis vintage (months)	51 (22, 97)	69 (31, 114)	79 (42, 122)	0.142^a, <0.001^b, 0.365^c
Dialysis frequency				0.960
Two times per week	6 (3.4)	4 (4.0)	43 (3.8)
Three times per week	171 (96.6)	97 (96.0)	1091 (96.2)
Relative IDWG (%)	2.10 (0.90, 4.00)	3.23 (1.88, 5.66)	2.86 (1.47, 4.63)	0.016^a, 0.083^b, 0.301^c
Pleural effusion	96 (54.2)	48 (47.5)	100 (8.8)	0.282^a, <0.001^b, <0.001^c
History of complications
Diabetes	74 (41.8)	26 (25.7)	190 (16.8)	0.007^a, <0.001^b, 0.023^c
Hypertension	163 (92.1)	91 (90.1)	898 (79.2)	0.570^a, <0.001^b, 0.009^c
Cerebral infarction	47 (27.0)	19 (18.8)	125 (11.2)	0.126^a, <0.001^b, 0.023^c
Coronary heart disease	37 (20.9)	16 (15.8)	97 (8.6)	0.302^a, <0.001^b, 0.015^c

HD: hemodialysis; BMI: body mass index; IDWG: interdialytic weight gain.

Data are mean (SD), n (%), or median (1/4, 3/4).

^aHaving-pneumonia group versus Will-Have-pneumonia group;

^bHaving-pneumonia group versus Non-pneumonia group;

^cWill-Have-pneumonia group versus Non-pneumonia group.

Table 2. The main reasons for the hospitalization of MHD patients in this study.

	Total (n = 1412)	Having-pneumonia group (n = 177)	Will-Have-pneumonia group (n = 101)	Non-pneumonia group (n = 1134)
Secondary hyperparathyroidism	645 (45.7)	13 (7.3)	37 (36.6)	595 (52.5)
Problems related to vascular access for HD (except infection)
Catheter	40 (2.8)	5 (2.8)	5 (5.0)	30 (2.6)
Arteriovenous fistula	289 (20.5)	22 (12.4)	21 (20.8)	246 (21.7)
Cardiovascular or cerebrovascular disease
Angiocardiopathy	64 (4.5)	13 (7.3)	8 (7.9)	43 (3.8)
Acute cerebral accident	35 (2.5)	4 (2.3)	8 (7.9)	23 (2.0)
Infection
Pulmonary	94 (6.7)	94 (53.1)	0	0
Vascular access for HD	32 (2.3)	6 (3.4)	4 (4.0)	22 (1.9)
Digestive system	17 (1.2)	4 (2.3)	1 (1.0)	12 (1.1)
Urinary system	9 (0.6)	2 (1.1)	0	7 (0.6)
Sepsis	2 (0.1)	1 (0.6)	0	1 (0.1)
Hemorrhagic disease
Alimentary tract	6 (0.4)	1 (0.6)	1 (1.0)	4 (0.4)
Urinary tract	4 (0.3)	0	0	4 (0.4)
Others	175 (12.4)	12 (6.8)	16 (15.8)	147 (13.0)

Data are n (%).

Table 3. Comparison between three groups of the patient in this study.

Parameters	Having-pneumonia group	Will-Have-pneumonia group	Non-pneumonia group	p Value
WBC (×10^9/L)	5.81 (4.65, 7.43)	5.76 (4.58, 7.13)	5.48 (4.42, 6.78)	0.580^a, 0.003^b, 0.911^c
NCP	72.80 (66.20, 79.50)	70.10 (64.75, 74.80)	67.10 (60.78, 72.50)	0.454^a, <0.001^b, 0.001^c
NLR	4.36 (2.99, 6.71)	3.83 (2.85, 5.21)	3.06 (2.28, 4.24)	0.543^a, <0.001^b, <0.001^c
CRP (>8 mg/L)	106 (60.6)	48 (49.0)	284 (26.0)	0.064^a, <0.001^b, <0.001^c
Hemoglobin (g/L)	100 (86, 112)	99 (86, 113)	107 (95, 120)	1.000^a, <0.001^b, <0.001^c
Albumin (g/L)	38.40 (34.70, 41.70)	39.20 (35.95, 42.30)	41.60 (38.30, 44.50)	1.000^a, <0.001^b, <0.001^c
Triglycerides (mmol/L)	1.34 (0.94, 1.74)	1.46 (0.97, 2.45)	1.45 (1.04, 2.11)	0.345^a, 0.037^b, 1.000^c
Total cholesterol (mmol/L)	3.30 (2.88, 4.03)	3.57 (2.98, 4.05)	3.63 (3.12, 4.30)	0.908^a, 0.016^b, 0.885^c
Uric acid (μmol/L)	390.00 (269.50, 451.00)	364.50 (290.25, 456.50)	416.00 (340.75, 481.25)	1.000^a, 0.019^b, 0.096^c
NT-proBNP (pg/mL)	17,106.00 (5274.00, 39,136.00)	12,443.50 (3636.25, 35,070.50)	4386.50 (2074.50, 10,959.00)	0.286^a, <0.001^b, <0.001^c
CK-MB (ng/mL)	2.00 (1.30, 3.20)	1.97 (1.15, 2.90)	1.70 (1.20, 2.70)	0.961^a, 0.013^b, 0.924^c
Troponin T (ng/mL)	0.08 (0.04, 0.12)	0.07 (0.05, 0.12)	0.05 (0.03, 0.08)	1.000^a, <0.001^b, <0.001^c
LVEF (%)	59 (55, 62)	58 (52, 62)	60 (57, 64)	1.000^a, 0.063^b, 0.023^c

WBC: white blood cell count; NCP: neutrophil count percentage; CRP: C-reactive protein; NLR: neutrophil-to-lymphocyte ratio; NT-proBNP: N-terminal B-type natriuretic peptide; LVEF: left ventricular ejection fraction; CK-MB: creatine kinase-MB.

Data are median (1/4, 3/4) or n (%).

^aHaving-pneumonia group versus Will-Have-pneumonia group;

^bHaving-pneumonia group versus Non-pneumonia group;

^cWill-Have-pneumonia group versus Non-pneumonia group.

Table 4. Data of noninvasive hemodynamic measurement.

Parameters	Having-pneumonia group	Will-Have-pneumonia group	Non-pneumonia group	p Value
TFC (1/KΩ)	39.55 (33.68, 47.90)	40.40 (34.55, 46.30)	34.50 (30.58, 39.43)	1.000^a, <0.001^b, <0.001^c
CO (L/min)	4.20 (3.45, 5.30)	4.50 (3.30, 5.50)	4.70 (3.90, 5.60)	1.000^a, 0.002^b, 0.061^c
CI [L/(min•m^2)]	2.60 (2.20, 3.10)	2.70 (2.10, 3.18)	2.80 (2.40, 3.30)	1.000^a, 0.001^b, 0.031^c
SVRI [dynes/(sec•cm^-5•m^2)]	2982.00 (2351.00, 3755.00)	2845.00 (2429.00, 4177.00)	2682.50 (2212.25, 3381.38)	1.000^a, 0.013^b, 0.007^c
LCWI (kgm/m^2)	3.30 (2.70, 4.00)	3.70 (3.00, 4.60)	3.80 (3.00, 4.80)	0.080^a, <0.001^b, 1.000^c
Heart rate (beats/min)	80 (71, 88)	82 (71, 94)	78 (70, 88)	0.216
Systolic BP (mmHg)	146 (126, 166)	152 (133, 170)	141 (124, 159)	0.324^a, 0.322^b, 0.003^c
Diastolic BP (mmHg)	79 (68, 91)	83 (75, 97)	84 (73, 93)	0.063^a, 0.014^b, 1.000^c

TFC: thoracic fluid content; CO: cardiac output; CI: cardiac index; SVRI: systemic vascular resistance index; LCWI: left cardiac work index.

Data are median (1/4, 3/4).

^aHaving-pneumonia group versus Will-Have-pneumonia group;

^bHaving-pneumonia group versus Non-pneumonia group;

^cWill-Have-pneumonia group versus Non-pneumonia group.

Table 5. Logistic regression analysis of risk factors for the development of pneumonia in MHD patients.

	Univariate analysis			Multivariate analysis
Variable	OR	95% CI	p Value	OR	95% CI	p Value
Age (years)	1.031	1.015–1.047	<0.001	1.017	0.998–1.035	0.074
Diabetes	1.722	1.074–2.763	0.024	1.313	0.764–2.255	0.325
NLR	1.118	1.061–1.179	<0.001	1.072	1.005–1.143	0.035
Hemoglobin (g/L)	0.977	0.967–0.988	<0.001	0.987	0.975–0.999	0.034
Albumin (g/L)	0.900	0.864–0.937	<0.001	0.950	0.902–1.000	0.048
NT-proBNP/1000 (pg/mL/1000)	1.006	1.003–1.009	<0.001	1.002	0.998–1.007	0.272
Troponin T (ng/mL)	1.522	0.718–3.224	0.273	–	–	–
TFC (1/KΩ)	1.051	1.030–1.072	<0.001	1.031	1.010-1.053	0.004
CI [L/(min•m^2)]	1.027	0.973–1.083	0.333	–	–	–

OR: odds ratio; 95% CI: 95% confidence interval; NLR: neutrophil–lymphocyte ratio; LVEF: left ventricular ejection fraction; TFC: thoracic fluid content; CI: cardiac index.