Effects of reduced exposure to cigarette smoking on changes in biomarkers of potential harm in adult smokers: results of combined analysis of two clinical studies

Figures & data

CONSORT flow diagram: The phases of the study.*Two subjects in the NS group were discontinued prematurely based on the investigator's judgment because a clinically significant incident or disease occurred on days 6 and 11, respectively. **CHC data in Study 2 was not used in this combined analysis.

Table 1. Demographics and baseline characteristics at screening, according to group.

	Gender (male)	Age (years)		BMI(kg/m^2)		Duration of smoking (year)		Daily cigarette consumption (cig.)
Subject group	N	Mean ± SD	(Min, Max)	Mean ± SD	(Min, Max)	Mean ± SD	(Min, Max)	Mean ± SD	(Min, Max)
SM (all)	124	28.7 ± 5.98	(21, 49)	21.0 ± 1.70	(18.5, 24.9)	8.27 ± 5.98	(1, 29)	20.9 ± 2.37	(20, 30)
CC1	52	29.0 ± 6.40	(21, 49)	21.2 ± 1.72	(18.5, 24.9)	8.48 ± 6.54	(1, 29)	21.3 ± 2.90	(20, 30)
NCIT	72	28.4 ± 5.69	(21, 44)	20.9 ± 1.68	(18.5, 24.9)	8.11 ± 5.58	(1, 23)	20.7 ± 1.88	(20, 30)
NS	50	29.9 ± 5.26	(21, 40)	21.9 ± 1.85	(18.6, 24.9)	–	–	–	–

BMI: body mass index; CC1: smoke 1 mg ISO tar conventional cigarette; NCIT: use noncombustion inhaler type of tobacco product; NS: nonsmokers; SD: standard deviation.

Table 2. Carboxyhemoglobin and plasma cotinine, according to group.

	Subject		Baseline^#1		Day 28 or Day 29^#2		p Value^#3
Biomarker	Group	N	Mean ± SD	Median (IQR)	Mean ± SD	Median (IQR)	NCIT vs CC1
COHb	CC1	52	4.84 ± 2.6	4.73 (2.98–6.77)	4.85 ± 1.82	4.86 (3.48–6.10)	<0.0001
(%)	NCIT	72	4.66 ± 1.8	4.93 (3.50–5.92)	1.58 ± 0.90	1.43 (0.99–2.13)
	NS	50	1.13 ± 1.1	0.85 (0.00–2.22)	0.95 ± 0.81	0.86 (0.19–1.58)
Plasma cotinine	CC1	52	212 ± 127	179 (118–290)	230 ± 109	229 (151–318)	<0.0001
(ng/ml)	NCIT	72	184 ± 97.4	156 (108–263)	24.1 ± 38.4	9.92 (4.99–24.4)
	NS	50	0.31 ± 0.3	0.25 (0.25–0.25)	0.25 ± 0.0	0.25 (0.25–0.25)

#1 Day 0 for COHb and Day 1 for plasma cotinine.

#2 Day 28 for COHb and Day 29 for plasma cotinine.

#3 Wilcoxon rank sum test (NCIT vs CC1).

CoHb: Carboxyhemoglobin; CC1: smoke 1 mg ISO tar conventional cigarette; NCIT: use noncombustion inhaler type of tobacco product; NS: nonsmokers; SD: standard deviation; IQR: interquartile range.

Table 3. Hematology biomarkers and biomarkers related to cardiovascular diseases (Arithmetic means [SE] for baseline).

	Subject		Baseline	p Value^#1
Biomarker	group	N	Mean [SE]	SM vs NS
hematology
RBC (10^4/μl)	SM	124	466 [2.9]	0.0373
	NS	50	477 [4.1]
WBC (/μl)	SM	124	6021 [118]	<0.0001
	NS	50	4892 [152]
Oxidative stress
urine 8-epi-PGF2α (pg/mg·Cr)	SM	124	321.67 [8.06]	<0.0001
	NS	50	236.63 [11.05]
urine 8-OHdG (ng/mg·Cr)	SM	124	6.80 [0.18]	0.0002
	NS	50	5.55 [0.32]
urine MDA (umol/g·Cr)	SM	124	1.26 [0.04]	0.0011
	NS	50	1.06 [0.06]
Antioxidant capacity
Total bilirubin (mg/dl)	SM	124	0.890 [0.03]	0.8473
	NS	50	0.883 [0.03]
Inflammation
hs-CRP (mg/dl)	SM	124	0.016 [0.09]	0.4225^#2
	NS	50	0.039 [0.01]
Inflammation/Endothelial dysfunction
FIB (mg/dl)	SM	124	240 [3.8]	0.6740
	NS	50	245 [7.6]
Platelet activation/Coagulation
urine 11-Dehydrothromboxane B2 (ng/g·Cr)	SM	124	3700 [91]	<0.0001
	NS	50	3002 [96]
Endothelial function/Coagulation
sICAM-1 (ng/ml)	SM	124	419 [8.8]	0.3235
	NS	50	407 [15.6]
Lipid metabolism
LDL-C (mg/dl)	SM	124	98.7 [2.3]	0.1002
	NS	50	106.3 [3.2]
HDL-C (mg/dl)	SM	124	52.0 [1.1]	0.0512
	NS	50	55.9 [1.5]
TC (mg/dl)	SM	124	166.5 [2.4]	0.0174
	NS	50	177.6 [3.3]
Glucose metabolism
Glucose (mg/dl)	SM	124	90.4 [0.43]	0.0030
	NS	50	92.8 [0.62]
HbA1c (%)	SM	124	4.70 [0.02]	0.4436
	NS	50	4.72 [0.04]

#1 Analysis of Variance (ANOVA) for baseline comparison (Since Study*Group interaction was not statistically significant in the model in all analyzed BoPH, the model included Study and Group.).

#2 Natural logarithm transformation was applied to hs-CRP due to non-normal distribution for ANOVA.

The average of Day 0 and Day 1 for individual was used as the individual value, and the mean of all individuals per group was used as baseline values for comparison between SM and NS.

RBC: red blood cell; WBC: white blood cell; 8-epi-PGF2α: urine 8-epi-prostaglandin F2α; 8-OHdG: urine 8-Hydroxy-2′-deoxyguanosine; MDA: urine malondialdehyde; FIB: Fibrinogen; hs-CRP: high sensitive-CRP; 11-DHTXB2: urine 11-dehydrothromboxane B2; HDL-C: High-density lipoprotein cholesterol; LDL-C: low-density lipoprotein cholesterol; TC: total cholesterol; HbA1c: hemoglobin A1c; SM: 1 mg ISO tar conventional cigarette smokers; NS: nonsmokers; SE: standard error.

Table 4. Hematology biomarkers and biomarkers related to cardiovascular diseases, according to group (Arithmetic means [SE] for baseline and Day 28/29).

	Subject		Baseline	Day 28/29	p Value^#1
Biomarker	group	N	Mean [SE]	Mean [SE]	NCIT vs CC1
Hematology
RBC (10^4/μl)	CC1	52	467 [4.7]	471 [3.9]	0.2714
	NCIT	72	465 [3.8]	467 [3.5]
	NS	50	477 [4.1]	475 [3.9]
WBC (/μl)	CC1	52	6002 [211.21]	5683 [162.84]	0.8389
	NCIT	72	6035 [136.55]	5651 [118.72]
	NS	50	4892 [151.91]	4976[133.52]
Oxidative stress
urine 8-epi-PGF2α (pg/mg·Cr)	CC1	52	326.56 [11.60]	299.57 [11.25]	0.0484
	NCIT	72	318.13 [11.12]	272.40 [8.67]
	NS	50	236.63 [11.05]	230.76[7.56]
urine 8-OHdG (ng/mg·Cr)	CC1	52	6.56 [0.26]	6.15 [0.29]	0.4914
	NCIT	72	6.97 [0.25]	6.09 [0.21]
	NS		5.55 [0.32]	5.38 [0.30]
urine MDA (umol/g·Cr)	CC1	52	1.39 [0.08]	1.18 [0.06]	0.0369
	NCIT	72	1.17 [0.04]	0.95 [0.04]
	NS	50	1.06 [0.06]	0.96 [0.05]
Antioxidant capacity
Total bilirubin (mg/dl)	CC1	52	0.917 [0.04]	0.898 [0.04]	0.0375
	NCIT	72	0.870 [0.04]	0.942 [0.03]
	NS	50	0.883 [0.03]	0.868 [0.03]
Inflammation
hs-CRP (mg/dl)	CC1	52	0.030 [0.01]	0.016 [0.13]	0.2118^#2
	NCIT	72	0.033 [0.01]	0.020 [0.13]
	NS	50	0.039 [0.01]	0.030 [0.00]
Inflammation/Endothelial dysfunction
FIB (mg/dl)	CC1	52	248 [6.3]	240 [5.5]	0.9695
	NCIT	72	234 [4.5]	231 [4.1]
	NS	50	245 [7.6]	230 [5.1]
Platelet activation/Coagulation
urine 11-Dehydrothromboxane B2 (ng/g·Cr)	CC1	52	3540 [131]	3978 [167]	<0.0001
	NCIT	72	3816 [124]	3570 [99]
	NS	50	3002 [96]	3252 [109]
Endothelial function/Coagulation
sICAM-1 (ng/ml)	CC1	52	414 [13.1]	407 [12.2]	0.2332
	NCIT	72	423 [12.0]	404 [9.9]
	NS	50	407 [16.0]	380 [13.8]
Lipid metabolism
LDL-C (mg/dl)	CC1	52	99 [3.7]	90 [3.1]	0.0286
	NCIT	72	99 [2.9]	95 [2.5]
	NS	50	106 [3.2]	102 [2.9]
HDL-C (mg/dl)	CC1	52	54 [1.8]	49 [1.4]	0.4293
	NCIT	72	51 [1.3]	49 [1.2]
	NS	50	56 [1.5]	51[1.3]
TC (mg/dl)	CC1	52	168 [4.1]	154 [3.3]	0.0110
	NCIT	72	166 [3.0]	160 [2.7]
	NS	50	178 [3.3]	168 [3.2]
Glucose metabolism
Glucose (mg/dl)	CC1	52	89.8 [0.7]	87.3 [0.7]	0.9320
	NCIT	72	90.8 [0.5]	87.9 [0.5]
	NS	50	92.8 [0.6]	88.9 [0.7]
HbA1c (%)	CC1	52	4.72 [0.04]	4.62 [0.03]	0.1611
	NCIT	72	4.68 [0.02]	4.62 [0.02]
	NS	50	4.72 [0.04]	4.65 [0.04]

#1 Analysis of Covariance (ANCOVA) for Day 28/29 comparison (Since Study*Group interaction was not statistically significant in the model in all analyzed BoPH, the model included Study, Group and Baseline as covariate).

#2 Natural logarithm transformation was applied to hs-CRP due to non-normal distribution for ANCOVA.

The average of the value of Day 28 and Day 29 for individual was used as the individual value (Day 28/29), and the mean of all individuals per group was used for comparison between NCIT group and CC1 group.

RBC: red blood cell; WBC: white blood cell; 8-epi-PGF2α: urine 8-epi-prostaglandin F2α; 8-OHdG: urine 8-Hydroxy-2′-deoxyguanosine; MDA: urine malondialdehyde; FIB: Fibrinogen; hs-CRP: high sensitive-CRP; 11-DHTXB2: urine 11-dehydrothromboxane B2; HDL-C: High-density lipoprotein cholesterol; LDL-C: low-density lipoprotein cholesterol; TC: total cholesterol; HbA1c: hemoglobin A1c; CC1: smoke 1 mg ISO tar conventional cigarette; NCIT: use noncombustion inhaler type of tobacco product; NS: nonsmokers; SE: standard error.

Figure 1. Biomarkers related to cardiovascular diseases according to group (mean ± SE). CC1: smoke 1 mg ISO tar conventional cigarette; NCIT: use noncombustion inhaler type of tobacco product; NS: nonsmokers; SE: standard error.

Calapai, G., et al., 2009. A cross-sectional investigation of biomarkers of risk after a decade of smoking. Inhalation toxicology, 21 (13), 1138–1143.

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