Genotoxic damage assessment using the micronucleus assay in buccal mucosa of different types of smokers: A cross-sectional study

Table 1 Distribution of sociodemographic characteristics of the studied population, n (%)/mean ± SD

Variable	NS	CS	MS	ES	RS	Total
Age1	32.55 ± 9.75	51.3 ± 12.49	30.6 ± 7.25	30.4 ± 9.47	68.05 ± 12.45	32.55 ± 9.75
Sex1
Female	14 (70)	9 (45)	2 (10)	10 (50)	19 (95)	54
Male	6 (30)	11 (55)	18 (90)	10 (50)	1 (5)	46
Education al level1
Illiterate	0 (0)	0 (0)	5 (25)	0 (0)	16 (80)	21
Primary	0 (0)	4 (20)	2 (10)	0 (0)	4 (20)	10
Secondary	3 (15)	9 (45)	10 (50)	0 (0)	0 (0)	22
University	9 (45)	5 (25)	3 (15)	11 (55)	0 (0)	28
Postgraduate	8 (40)	2 (10)	0 (0)	9 (45)	0 (0)	19
Place of origin
Domestic	20 (100)	20 (100)	18 (90)	20 (100)	20 (100)	98
Foreign	0 (0)	0 (0)	2 (10)	0 (0)	0 (0)	2
Residence area1
Rural	0 (0)	6 (30)	10 (50)	4 (20)	0 (0)	20
Urban	20 (100)	14 (70)	10 (50)	16 (80)	20 (100)	80
Socioeconomic status1
1	0 (0)	7 (35)	6 (30)	0 (0)	0 (0)	13
2	5 (25)	7 (35)	11 (55)	3 (15)	20 (100)	46
3	9 (45)	4 (20)	1 (5)	6 (30)	0 (0)	16
4	2 (10)	0 (0)	2 (10)	7 (35)	0 (0%)	11
5	4 (20)	2 (10)	0 (0)	4 (20)	0 (0)	10
Comorbidities1
Healthy	19 (95)	17 (85)	15 (75)	9 (45)	17 (85)	77
Controlled systemic disease	0 (0)	2 (10)	3 (15)	9 (45)	2 (10)	16
Uncontrolled systemic disease	0 (0)	0 (0)	2 (10)	1 (5)	0 (0)	3
Obesity	1 (5)	1 (5)	0 (0)	1 (5)	1 (5)	4
Reason for habit
Pleasure	-	13 (65)	18 (90)	2 (10)	3 (15)	36
Anxiety	-	0 (0)	0 (0)	6 (30)	2 (10)	8
Social	-	7 (35)	2 (10)	12 (60)	1 (5)	22
Cultural	-	0 (0)	0 (0)	0 (0)	14 (70)	14

¹Statistically significant differences between groups (P < 0.05, Krus-kal-Wallis for age and χ² for categorical variables).

NS: Non-smokers; CS: Conventional smokers; MS: Marijuana smokers; ES: Electronic cigarette smokers; RS: Reverse smokers.

Table 2 Distribution of lesions and affected anatomical sites

Variables		NS	CS	MS	ES	RS	Total
Type of lesion (presumptive diagnosis)	Absent	20	7	16	15	0	58
	White lesions (leukoplakia)	0	3	1	2	6	12
	Red and/or heterogeneous lesions (erythroplasia/Leukoerythroplasia)	0	0	0	0	3	3
	Reverse smoker’s palate	0	0	0	0	16	14
	Carcinoma in situ	0	0	0	1	1	2
	Melanosis	0	5	0	0	14	21
	Leukoedema	0	5	3	2	2	12
Anatomical site	Palate	0	5	0	2	20	27
	Tongue	0	1	0	1	4	6
	Buccal mucosa	0	6	4	2	10	22
	Gingiva	0	8	0	0	3	11
	Oropharynx	0	0	0	2	0	2
	Lips	0	2	0	0	1	3

NS: Non-smokers; CS: Conventional smokers; MS: Marijuana smokers; ES: Electronic cigarette smokers; RS: Reverse smokers.

Table 3 Comparison of micronucleus frequencies per thousand cells between study and control groups, median ± SD

Groups	Micronucleus frequency	Z-Statistic	P value
MS	1.3 ± 1.14	0.13	0.89
ES	2.8 ± 2.41	0.43	< 0.001
CS	3.6 ± 2.25	-3.96	< 0.001
RS	4.4 ± 2.3	-5.21	< 0.001
Control	1.05 ± 0.69

CS: Conventional smokers; MS: Marijuana smokers; ES: Electronic cigarette smokers; RS: Reverse smokers.

Table 4 Comparison of median micronucleus frequency by smoker type, Z value (P value)

Smoker type	Control	MS	CS	RS	ES
Control		-1.02 (0.15)	-4.27 (0.00)a	-5.24 (0.00)a	-2.95 (0.00)a
MS	-1.02 (0.15)		-3.25 (0.00)a	-4.21 (0.00)a	-1.92 (0.02)a
CS	-4.27 (0.00)a	-3.25 (0.00)a		-0.96 (0.16)	1.27 (0.20)
RS	-5.24 (0.00)a	-4.21 (0.00)a	-0.96 (0.16)		2.28 (0.01)a
ES	-2.95 (0.00)a	-1.92 (0.02)a	1.27 (0.20)	2.28 (0.01)a

^aP < 0.05, statistically significant value. Dunn's test with Bonferroni adjustment.

CS: Conventional smokers; MS: Marijuana smokers; ES: Electronic cigarette smokers; RS: Reverse smokers.

Table 5 Contingency table odds ratio–adjusted model

Variable	Crude OR	Adjusted OR	P value
Age	3.3	0.99	0.97
Housing	0.21	0.73	0.74
Alcohol consumption	0.23	0.37	0.25

OR: Odds ratio.