Figure 1
Means of total, direct and indirect serum bilirubin versus cigarette smoking among Korean men (p for trend < 0.01). (A) Smoking status. (B) smoking amount (cigarettes/d) in current smokers. (C) Smoking duration (y) in current smokers. (D) Pack-years in current smokers.
TB, total bilirubin; DB, direct bilirubin; IDB, indirect bilirubin.
Table 1.General characteristics of Korean men according to smoking status
|
Never smoker (n=14 992) |
Ex-smoker (n=11 041) |
Current smoker (n=22 007) |
Age (y) |
41.5±8.4 |
43.0±8.0 |
40.2±7.2 |
Body mass index (kg/m2) |
24.2±2.8 |
24.5±2.7 |
24.5±3.0 |
Waist circumference (cm) |
84.1±9.8 |
85.2±10.6 |
85.2±13.4 |
Systolic blood pressure (mmHg) |
120.8±12.7 |
121.1±12.4 |
119.8±12.5 |
Diastolic blood pressure (mmHg) |
76.0±9.1 |
76.6±8.8 |
75.6±9.1 |
Total cholesterol (mg/dL) |
192.9±32.7 |
195.6±32.7 |
195.2±33.6 |
Triglyceride (mg/dL) |
146.7±90.0 |
159.3±98.8 |
178.0±109.0 |
HDL cholesterol (mg/dL) |
48.7±8.3 |
48.6±8.3 |
47.9±8.1 |
Fasting serum glucose (mg/dL) |
91.8±18.7 |
93.0±20.1 |
91.5±20.8 |
Total bilirubin (mol/L) |
16.1±5.6 |
15.9±5.4 |
14.8±5.3 |
Direct bilirubin (mol/L) |
6.0±2.0 |
5.8±2.0 |
5.3±1.9 |
Indirect bilirubin (mol/L) |
10.1±3.9 |
9.8±3.7 |
9.2±3.6 |
Hemoglobin (g/L) |
15.0±0.9 |
15.2±0.9 |
15.5±1.0 |
Alanine aminotransferase (U/L) |
25.1±14.2 |
25.9±13.9 |
25.6±17.9 |
Aspartate aminotransferase (U/L) |
30.1±25.2 |
30.8±23.9 |
31.9±25.7 |
Gamma-glutamyltransferase (U/L) |
39.9±40.7 |
46.8±46.8 |
54.1±63.1 |
Uric acid (mg/dL) |
6.1±1.2 |
6.2±1.2 |
6.3±1.2 |
Alcohol intake |
|
|
|
No |
20.9 |
10.5 |
7.8 |
Yes |
79.1 |
89.5 |
92.2 |
Table 2.Multivariable adjusted odds ratios and 95% confidence intervals for the lowest quartile of bilirubin subtypes compared to the highest quartile of bilirubin subtypes according to cigarette smoking in current male smokers
Cigarette smoking |
Serum bilirubin subtypes
|
n |
Total bilirubin
|
Direct bilirubin
|
Indirect bilirubin
|
n1
|
Model I2
|
Model II3
|
n1
|
Model I2
|
Model II3
|
n1
|
Model I2
|
Model II3
|
Smoking amount (cigarette/d) |
|
|
|
|
|
|
|
|
|
|
Never smoker |
14 992 |
2896 |
1.0 |
1.0 |
3397 |
1.0 |
1.0 |
1927 |
1.0 |
1.0 |
1 - 9 |
4535 |
916 |
1.1 (1.0, 1.2) |
1.2 (1.1, 1.3) |
1056 |
1.2 (1.1, 1.3) |
1.2 (1.1, 1.3) |
612 |
1.1 (1.0, 1.2) |
1.1 (1.0, 1.2) |
10 - 19 |
15 481 |
3799 |
1.5 (1.4, 1.6) |
1.6 (1.5, 1.7) |
4080 |
1.4 (1.3, 1.5) |
1.5 (1.4, 1.5) |
2679 |
1.5 (1.4, 1.6) |
1.6 (1.5, 1.7) |
≥20 |
10 151 |
2765 |
1.8 (1.6, 1.9) |
1.9 (1.8, 2.0) |
2966 |
1.7 (1.6, 1.8) |
1.8 (1.7, 1.9) |
1950 |
1.7 (1.6, 1.8) |
1.9 (1.7, 2.0) |
Smoking duration (y) |
|
|
|
|
|
|
|
|
|
|
Never smoker |
14 992 |
2896 |
1.0 |
1.0 |
3397 |
1.0 |
1.0 |
1927 |
1.0 |
1.0 |
1 - 12 |
8047 |
1631 |
1.1 (1.1, 1.2) |
1.1 (1.1, 1.2) |
1814 |
1.1 (1.1, 1.2) |
1.1 (1.1, 1.2) |
1106 |
1.1 (1.0, 1.2) |
1.1 (1.0, 1.2) |
13 - 21 |
16 501 |
4022 |
1.5 (1.4, 1.6) |
1.5 (1.4, 1.6) |
4301 |
1.4 (1.3, 1.5) |
1.4 (1.3, 1.5) |
2835 |
1.5 (1.4, 1.6) |
1.5 (1.4, 1.6) |
≥22 |
8254 |
2279 |
1.9 (1.8, 2.0) |
1.9 (1.8, 2.0) |
2458 |
1.8 (1.7, 1.9) |
1.8 (1.7, 1.9) |
1608 |
1.8 (1.7, 2.0) |
1.8 (1.7, 2.0) |
Pack-years4
|
|
|
|
|
|
|
|
|
|
|
Never smoker |
14 992 |
2896 |
1.0 |
1.0 |
3397 |
1.0 |
1.0 |
1927 |
1.0 |
1.0 |
1 - 6 |
7360 |
1511 |
1.1 (1.1, 1.2) |
1.2 (1.1, 1.3) |
1695 |
1.1 (1.0, 1.2) |
1.2 (1.1, 1.3) |
1011 |
1.1 (1.0, 1.2) |
1.1 (1.0, 1.2) |
7 - 19 |
14 548 |
3585 |
1.4 (1.4, 1.5) |
1.6 (1.5, 1.6) |
3827 |
1.4 (1.3, 1.4) |
1.5 (1.4, 1.5) |
2552 |
1.4 (1.3, 1.5) |
1.6 (1.5, 1.7) |
≥20 |
7576 |
2200 |
1.7 (1.6, 1.9) |
2.1 (1.9, 2.2) |
2376 |
1.5 (1.4, 1.6) |
1.9 (1.8, 2.0) |
1548 |
1.7 (1.6, 1.9) |
2.0 (1.9, 2.2) |
Table 3.ORs and 95% CIs for the lowest quartile of total bilirubin concentration compared to the highest quartile of total bilirubin concentrations according to age, BMI, hypertension, diabetes, TG/HDL-C, and alcohol intake in current male smokers
Variables |
Smoking amount (cigarette/d)
|
NS1
|
1-9
|
10 - 19
|
≥ 20
|
n |
OR (95% CI) |
n |
OR (95% CI) |
n |
OR (95% CI) |
Age (y) |
|
|
|
|
|
|
|
< 40 |
7305 |
2597 |
1.1 (0.9, 1.2) |
8134 |
1.4 (1.3, 1.5) |
3548 |
1.6 (1.4, 1.7) |
≥40 |
7687 |
1938 |
1.1 (1.0, 1.3) |
7347 |
1.4 (1.3, 1.5) |
6603 |
1.6 (1.5, 1.7) |
BMI (kg/m2) |
|
|
|
|
|
|
|
< 23 |
10 221 |
1592 |
1.1 (0.9, 1.2) |
4975 |
1.5 (1.4, 1.7) |
2782 |
1.8 (1.7, 2.1) |
≥23 |
22 827 |
2943 |
1.1 (1.0, 1.2) |
10 506 |
1.3 (1.2, 1.4) |
7369 |
1.5 (1.4, 1.6) |
Hypertension |
|
|
|
|
|
|
|
No |
12 869 |
3985 |
1.2 (0.9, 1.5) |
13 464 |
1.2 (1.1, 1.4) |
8484 |
1.4 (1.2, 1.6) |
Yes |
2123 |
550 |
1.1 (1.0, 1.2) |
2017 |
1.4 (1.3, 1.5) |
1667 |
1.6 (1.5, 1.7) |
Diabetes |
|
|
|
|
|
|
|
No |
14 445 |
4403 |
1.3 (0.8, 1.9) |
14 911 |
1.2 (1.0, 1.6) |
9506 |
1.5 (1.2, 1.9) |
Yes |
547 |
132 |
1.1 (1.0, 1.2) |
570 |
1.4 (1.3, 1.5) |
645 |
1.6 (1.5, 1.7) |
TG/HDL-C (mg/dL) |
|
|
|
|
|
|
|
<3 |
8990 |
2551 |
1.2 (1.1, 1.3) |
7721 |
1.4 (1.3, 1.5) |
4474 |
1.6 (1.5, 1.7) |
≥3 |
6002 |
1984 |
1.0 (0.9, 1.1) |
7760 |
1.3 (1.2, 1.4) |
5677 |
1.5 (1.4, 1.6) |
Alcohol intake |
|
|
|
|
|
|
|
No |
3106 |
379 |
1.0 (0.8, 1.3) |
1279 |
1.9 (1.6, 2.1) |
1055 |
1.9 (1.7, 2.2) |
Yes |
11 731 |
4110 |
1.1 (1.0, 1.2) |
14 045 |
1.4 (1.3, 1.5) |
8942 |
1.6 (1.5, 1.7) |