Table 1.

Comparisons of general characteristics on subjects according to smoking status

	Non-smoker * (n = 2,270)	Ex-smoker * (n = 2,680)	Current smoker * (n = 3,593)	Total (n = 8,543)	p value †	Post-hoc comparison
Age (years)	47.5 ± 9.4	48.9 ± 8.0	43.5 ± 9.7	46.3 ± 9.4	<0.001	c < a < b
Working period (years)	23.1 ± 10.2	24.4 ± 9.2	19.8 ± 10.0	22.1 ± 10.0	<0.001	c < a < b
Noise level (decibel)	86.8 ± 3.0	86.5 ± 2.9	86.8 ± 3.1	86.7 ± 3.0	0.001	b < a,c
Body mass index (kg/m2)	23.4 ± 2.3	23.5 ± 2.3	23.4 ± 2.5	23.4 ± 2.4	0.013	a < b
Mean arterial pressure (mmHg)	93.2 ± 8.5	93.3 ± 8.5	91.9 ± 8.5	92.7 ± 8.5	<0.001	c < a,b
Fasting blood sugar (mg/㎗)	98.2 ± 12.0	98.9 ± 12.8	97.4 ± 12.8	98.1 ± 12.6	<0.001	c < b
Total cholesterol (mg/㎗)	188.9 ± 31.7	191.4 ± 31.9	190.2 ± 32.3	190.2 ± 32.0	0.023	a < b
Triglyceride (mg/㎗)	115.7 ± 71.5	123.8 ± 88.2	141.9 ± 105.8	129.3 ± 92.9	<0.001	a < c
HDL cholesterol (mg/㎗)	53.5 ± 13.1	53.1 ± 12.9	51.4 ± 12.7	52.5 ± 12.9	<0.001	c < a,b
Hemoglobin (g/㎗)	14.9 ± 0.9	14.9 ± 0.9	15.1 ± 0.9	15.0 ± 0.9	<0.001	a,b < c
Hematocrit (%)	43.4 ± 2.6	43.1 ± 2.6	43.9 ± 2.7	43.5 ± 2.7	<0.001	a,b < c
	(n = 735)	(n = 800)	(n = 1,227)	(n = 2,762)
Red blood cell count (104/㎣)	468.9 ± 32.8	465.5 ± 33.4	468.8 ± 34.2	467.9 ± 33.6	0.020	b < a,c
	(n = 1,084)	(n = 1,129)	(n = 1,673)	(n = 3,886)
Carboxyhemoglobin (%)	0.58 ± 0.75	0.52 ± 0.70	2.26 ± 1.83	1.29 ± 1.57	<0.001	a,b < c
	(n = 627)	(n = 679)	(n = 1,007)	(n = 2,313)
Pure tone audiometry of right ear (dBHL)
1 kHz	16.4 ± 11.9	16.9 ± 12.2	15.4 ± 10.5	16.2 ± 11.4	<0.001	c < a,b
2 kHz	19.7 ± 15.2	20.3 ± 15.3	17.7 ± 13.8	19.0 ± 14.7	<0.001	c < a,b
3 kHz	28.1 ± 20.3	30.0 ± 20.8	24.8 ± 19.4	27.3 ± 20.2	<0.001	c < a < b
4 kHz	33.8 ± 22.0	36.1 ± 22.4	30.2 ± 21.7	33.0 ± 22.1	<0.001	c < a < b

mean ± standard deviation.

^* a: Non-smoker, b: Ex-smoker, c: Current smoker.

^†p-value was calculated by ANOVA.