The impact of exposure to biomass smoke versus cigarette smoke on inflammatory markers and pulmonary function parameters in patients with chronic respiratory failure

Figures & data

Table 1 Patient characteristics, exposure data, and inflammatory markers in study groups

	Cigarette smoke exposure group (n=55)	Biomass smoke exposure group (n=51)	p-valueb
Patient characteristics
Age, mean (SD)	71.0 (12.0)	73.0 (11.0)	0.38
Gender, n (%)
Male	4 (7.3)	3 (5.9)	0.773c
Female	51 (92.7)	48 (94.1)
Body mass index (kg/m^2)	27.0 (7.0)	27.0 (7.0)	0.84
Amount of exposure
Cigarette pack/year, median (25–75 percentile)	45.0 (30.0–50.0)	–	–
Biomass exposure/year, median (25–75 percentile)	–	18.0 (10.0–20.0)	–
Use of biomass fuels, mean (SD)
For heating	–	48 (94.1)	–
For cooking	–	31 (60.8)	–
Hemogram, mean (SD)
White blood cells (10^9/L)	8.6 (2.7)	7.7 (3.0)	0.09
Hematocrit (%)	39.0 (6.1)	36.0 (5.7)	0.011
MPV (fL)	8.6 (1.0)	8.6 (1.0)	0.97
Platelet (10^9/L)	256.0 (64.0)	242.0 (80.0)	0.31
Inflammatory markers, mean (SD)
PLT/MPV	31.0 (10.0)	29.0 (11.0)	0.41
CRP (mg/L) median (min-max)	7.3 (3.3–12.5)	8.7 (3.0–15.0)	0.46d
NLR	3.5 (1.5)	3.4 (1.5)	0.65
Blood biochemistry, mean (SD)
Blood glucose (mg/dL)	111.0 (40.0)	107.0 (25.0)	0.53
BUN (mg/dL)a	31.0 (13.0)	33.0 (19.0)	0.64
Creatinine (mg/dL)	0.8 (0.5)	1.0 (0.2)	0.013

Notes:

a Missing data for 22 and 14 patients in the smoking and biomass groups, respectively.

b Student’s t-test,

c χ²-test,

d Mann–Whitney U test. Values in bold indicate statistical significance (p<0.05).

Abbreviations: BUN, blood urea nitrogen; CRP, C-reactive protein; MPV, mean platelet volume; NLR, neutrophil to lymphocyte ratio; PLT, platelet.

Table 2 Arterial blood gas analysis and spirometry findings in study groups

	Cigarette smoke exposure group (n=55)		Biomass smoke exposure group (n=51)		p-valuea
	n	Mean (SD)	n	Mean (SD)
Arterial blood gas analysis
pH	53	7.40 (0.04)	27	7.36 (0.03)	0.001
PaCO2 (mmHg)	53	47.0 (8.0)	27	51.0 (8.0)	0.026
PaO2/FiO2 (mmHg)	52	333.0 (99.0)	25	338.0 (103.0)	0.84
HCO3 (mmol)	53	30.0 (5.0)	27	29.0 (4.0)	0.65
SaO2 (%)	53	92.0 (5.0)	25	92.0 (5.0)	0.82
Respiratory function test
FEV1 (mL)	50	752.0 (383.0)	19	736.0 (431.0)	0.88
FEV1 (%)	48	38.0 (16.0)	19	40.0 (12.0)	0.69
FVC (mL)	50	1,063.0 (592.0)	19	744.0 (410.0)	0.035
FVC (%)	50	45.0 (19.0)	19	39.0 (19.0)	0.25
FEV1/FVC	50	58.0 (12.0)	19	75.0 (14.0)	0.001
FEV1/FVC <70, n (%)	50	41 (82.0)	19	7 (36.8)	<0.001b

Notes:

a Student’s t-test,

b χ²-test. Values in bold indicate statistical significance (p<0.05).

Abbreviations: FEV₁, forced expiratory volume in 1 second; FiO₂, fraction of inspired oxygen; FVC, forced vital capacity; PaCO₂, carbon dioxide partial pressure; PaO₂, oxygen partial pressure; SaO₂, oxygen saturation.