Clinical Predictors of High Blood Eosinophils in Chronic Obstructive Pulmonary Disease

Figures & data

Table 1 Comparison of Clinical Characteristics in COPD Patients with Different Blood Eosinophil Levels

	<100 (125) Cells/μL	100–300 (195) cells/μL	≥300 (55) cells/μL	P
Male	60 (48.0)	134 (68.7)	38 (69.1)	<0.001*
Female	65 (52.0)	61 (31.3)	17 (30.9)	<0.001*
Age (≥ 40 years)	62.4±11.5	63.1±10.4	65.5±10.1	0.195
BMI	24.5±3.4	24.1±2.9	22.7±2.5	0.001*
Family income (10^4 yuan/year)	2.0 (1.0, 3.0)	2.0 (1.0, 4.0)	1.0 (0.5,3.0)	0.012*
Raising pets	55 (44.4)	98 (51.0)	35 (64.8)	0.043*
Biomass use^a	53 (42.7)	97 (50.8)	38 (70.4)	0.003*
Duration of biomass exposure^b	40.4±17.0	38.3±18.6	42.1±17.2	0.511
Smoking status
Current smoker	33 (26.4)	73 (37.4)	19 (34.5)	0.089
Former smoker	13 (10.4)	27 (13.9)	10 (18.2)	–
Never smoking	79 (63.2)	95 (48.7)	26 (47.3)	–
Bromopnea	13 (10.7)	22 (11.6)	5 (9.6)	0.913
Teeth problem^c	88 (71.5)	125 (65.1)	36 (66.7)	0.488
Periodontitis^d	19 (15.3)	22 (11.5)	7 (13.2)	0.608
CAT	7.5 (3.0, 14.0)	6.0 (2.0, 11.25)	5.0 (2.0, 11.0)	0.262
NEU%	62.2 (57.1,68.9)	60.1 (54.9, 66.5)	57.0 (53.0, 62.0)	<0.001*
WBC (10^9/L)	5.4 (4.6, 6.4)	6.0 (5.1, 7.3)	6.4 (5.7, 7.2)	<0.001*
TG (mmol/L)	1.4 (1.1, 1.8)	1.3 (1.1, 1.8)	1.6 (1.2, 1.7)	0.474
TC (mmol/L)	4.9 (4.5, 5.7)	4.8 (4.2, 5.5)	5.4 (4.1, 6.1)	0.169
HDL (mmol/L)	1.5 (1.3, 1.9)	1.5 (1.3, 1.7)	1.5 (1.2, 1.8)	0.642
LDL (mmol/L)	2.7±0.8	2.6±0.7	2.9±0.9	0.175
FEV1% predicted (%)	90.8±22.6	89.0±20.7	88.0±22.0	0.712
Pre-bronchodilator
PEF (L/s)	4.7 (3.0, 6.2)	4.6 (3.5, 6.1)	4.4 (3.3, 6.0)	0.710
FEV1: FVC (%)	63.3 (57.7, 67.8)	63.1 (56.7, 63.6)	60.0 (51.6, 66.1)	0.107
Post-bronchodilator
PEF (L/s)	4.8 (3.4, 6.5)	5.0 (3.9, 6.3)	4.6 (3.3, 6.6)	0.423
FEV1: FVC (%)	65.5 (59.3, 68.0)	64.1 (57.3, 67.9)	63.1 (51.9, 67.3)	0.143
GOLD stage ≤1	93 (74.4)	140 (71.8)	40 (72.7)	0.878

Notes: Data are presented as n (%), mean ± SD or median (interquartile range). *p<0.05. ^aDefined as using woody fuels or animal waste for cooking or heating during the past 6 months or longer. ^bDefined as consecutive years of biomass exposure. ^cDefined as having at least one of the following conditions in the past one year, including swollen gums, gingival bleeding, toothache, tooth losing and damaging. ^dDefined as being diagnosed with periodontitis by dentists.

Abbreviations: COPD, chronic obstructive pulmonary disease; BMI, body mass index; CAT, COPD assessment test; NEU%, percentage of neutrophils; WBC, leukocyte count; TG, triglycerides; TC, total cholesterol; HDL, high-density lipoprotein; LDL, low-density lipoprotein; FEV1, forced expiratory volume in 1 second; PEF, peak expiratory flow; FVC, forced vital capacity.

Table 2 Factors Associated with Blood Eosinophil Count in COPD Patients According to Univariate Linear Regression Analysis

Factors	Unstandardized Coefficients		Standardized Coefficients	P value	Adjusted R^2
	Beta	95% CI	Beta
Age (≥ 40 years)	0.934	−0.944 to 2.813	0.051	0.329	0.000
Male	44.312	6.556 to 82.067	0.119	0.022*	0.011
BMI	−7.716	−13.989 to −1.443	−0.124	0.016*	0.013
Family income	−4.552	−11.663 to 2.559	−0.067	0.209	0.002
Raising pets	43.130	2.423 to 83.838	0.108	0.038*	0.009
Biomass use	64.788	24.307 to 105.268	0.162	0.002*	0.024
Duration of biomass exposure	0.484	−1.445 to 2.413	0.037	0.62	−0.004
Former smoking	45.279	−5.307 to 95.865	0.091	0.079	0.006
Bromopnea	15.726	−50.507 to 81.959	0.025	0.641	−0.002
Teeth problem	13.815	−29.885 to 57.516	0.032	0.535	−0.002
Periodontitis	37.972	−31.547 to 107.490	0.056	0.283	0.056
TG	4.318	−28.002 to 36.638	0.018	0.793	−0.004
TC	−10.048	−36.020 to 15.924	−0.053	0.447	−0.002
HDL	−58.688	−113.664 to −3.713	−0.144	0.037*	0.016
LDL	−3.744	−38.924 to 31.435	−0.014	0.834	−0.005

Note: *p<0.05.

Table 3 Factors Associated with Blood Eosinophil Count in COPD Patients According to Multivariable Linear Regression Analysis

Independent Variables	Unstandardized Coefficients		Standardized Coefficients	P value
	Beta	95% CI	Beta
Constant	98.729	−180.317 to 377.775	–	0.486
Age (≥ 40 years)	2.819	0.639 to 5.000	0.183	0.012*
Male	66.125	16.350 to 115.900	0.191	0.009*
BMI	−4.888	−12.186 to 2.409	−0.093	0.188
Family income	−1.383	−9.204 to 6.438	−0.027	0.728
Raising pets	41.957	3.964 to 79.951	0.137	0.478
Biomass use	27.373	−25.966 to 80.712	0.083	0.313
Former smoking	10.545	−60.298 to 81.388	0.021	0.769
TC	3.267	−27.088 to 33.622	0.025	0.832
HDL	−64.682	−123.451 to −5.914	−0.179	0.031*
LDL	13.928	−30.342 to 58.199	0.069	0.536

Notes: R² = 0.114, adjusted R² = 0.067. Adjusted for age, male gender, BMI, family income, raising pets, biomass use, former smoking, TC, HDL and LDL. *p<0.05.