Table 1.

Baseline characteristics and follow-up smoking status of subjects in the study sample

	N (%)	tGSH [μM]	tCys [μM]
		Mean ± SD	Mean ± SD
N	434	1.51 ± 0.93	265.6 ± 85.9
Sex
Male	193 (44.5)	1.46 ± 0.66	261.2 ± 89.7
Female	241 (55.5)	1.56 ± 1.10	271.0 ± 80.7
Age at interview
< 45 years	168 (38.7)	1.50 ± 0.64	255.2 ± 90.8
45 – 54	162 (37.3)	1.57 ± 1.24	268.1 ± 85.0
55 – 64	79 (18.2)	1.39 ± 0.61	277.6 ± 71.8
≥ 65	25 (5.8)	1.60 ± 1.11	281.3 ± 94.9
Education
Low (≤ 9 years)	229 (53.8)	1.45 ± 0.61	268.3 ± 81.1
Moderate (10 – 11 years)	106 (24.9)	1.44 ± 0.71	257.4 ± 94.4
High (≥ 12 years)	91 (21.4)	1.73 ± 1.57	271.9 ± 88.5
Unknown	8
BMI
25	192 (46.2)	1.57 ± 1.18	253.4 ± 83.1
> 25 – < 30	152 (36.5)	1.44 ± 0.66	270.7 ± 87.2
≥ 30	72 (17.3)	1.59 ± 0.67	279.2 ± 86.7
History of diseases
Coronary heart disease	33 (8.1)	1.41 ± 0.55	292.8 ± 96.7
Type 2 diabetes mellitus	46 (11.2)	1.48 ± 0.67	290.5 ± 84.5
Cancer	16 (3.9)	1.39 ± 0.43	230.2 ± 41.4
Cigarette consumption
10 – 19	122 (28.7)	1.40 ± 0.62	262.4 ± 95.4
20 – 29	170 (40.0)	1.54 ± 0.75	265.7 ± 84.4
≥ 30	133 (31.3)	1.59 ± 1.31	269.4 ± 80.0
Unknown	9
Self-reported smoking status at follow-up
Continuing smoker	370 (85.3)
Quitter	64 (14.7)
Cotinine-validated smoking status at follow-up
Continuing smoker	379 (87.3)
Abstinent quitter	55 (12.7)