Table 1 Comparisons of general characteristics on subjects according to smoking status

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/dℓ)

98.2 ± 12.0

98.9 ± 12.8

97.4 ± 12.8

98.1 ± 12.6

<0.001

c < b

Total cholesterol (mg/dℓ)

188.9 ± 31.7

191.4 ± 31.9

190.2 ± 32.3

190.2 ± 32.0

0.023

a < b

Triglyceride (mg/dℓ)

115.7 ± 71.5

123.8 ± 88.2

141.9 ± 105.8

129.3 ± 92.9

<0.001

a < c

HDL cholesterol (mg/dℓ)

53.5 ± 13.1

53.1 ± 12.9

51.4 ± 12.7

52.5 ± 12.9

<0.001

c < a,b

Hemoglobin (g/dℓ)

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/mm3)

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