Table 1. Characteristics of subjects by smoking category.
| (A) Male Subjects | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| P Value † | |||||||||||
| Non-Smokers ( n =7,671) | EX1 Smokers ( n = 5,035) | EX2 Smokers ( n = 1,152) | Current Smokers ( n = 5,261) | ANOVA P Value § | NON vs EX1 | NON vs EX2 | NON vs CUS | EX1 vs EX2 | EX1 vs CUS | EX2 vs CUS | |
| Age, year | 48.0 | 55.0 | 47.0 | 48.0 | ＜0.001 | ＜0.001 | 0.058 | ＜0.001 | ＜0.001 | ＜0.001 | 0.952 |
| (16.0) | (17.0) | (15.0) | (13.0) | ||||||||
| BMI, kg/m 2 | 23.2 | 23.4 | 23.5 | 23.5 | ＜0.001 | 0.563 | ＜0.001 | 0.007 | 0.005 | 0.216 | 0.139 |
| (3.9) | (3.5) | (4.0) | (4.1) | ||||||||
| Systolic blood pressure, mmHg | 115.0 | 118.0 | 116.0 | 114.0 | ＜0.001 | ＜0.001 | 0.854 | 0.004 | 0.006 | ＜0.001 | 0.041 |
| (21.0) | (22.0) | (21.0) | (21.0) | ||||||||
| Diastolic blood pressure, mmHg | 71.0 | 73.0 | 71.0 | 71.0 | ＜0.001 | ＜0.001 | 0.935 | 0.909 | 0.037 | ＜0.001 | 0.786 |
| (15.0) | (15.0) | (15.8) | (16.0) | ||||||||
| Glucose metabolism | |||||||||||
| Fasting glucose, mg/dL | 99.0 | 101.0 | 101.0 | 100.0 | ＜0.001 | ＜0.001 | ＜0.001 | ＜0.001 | 0.644 | 0.988 | 0.797 |
| (11.0) | (13.0) | (13.0) | (13.0) | ||||||||
| HbA1c, % | 5.5 | 5.6 | 5.6 | 5.6 | ＜0.001 | ＜0.001 | ＜0.001 | ＜0.001 | 0.419 | 0.007 | 0.988 |
| (0.4) | (0.4) | (0.4) | (0.4) | ||||||||
| Albumin, mg/dL | 4.4 | 4.3 | 4.3 | 4.3 | ＜0.001 | ＜0.001 | 0.283 | ＜0.001 | ＜0.001 | 0.002 | 0.004 |
| (0.3) | (0.4) | (0.3) | (0.3) | ||||||||
| Creatinine, mg/dL | 0.90 | 0.89 | 0.88 | 0.86 | ＜0.001 | 0.498 | 0.002 | ＜0.001 | 0.042 | ＜0.001 | 0.551 |
| (0.16) | (0.17) | (0.14) | (0.16) | ||||||||
| ALT, IU/L | 21.0 | 20.0 | 21.0 | 21.0 | ＜0.001 | ＜0.001 | 0.049 | 0.941 | ＜0.001 | ＜0.001 | 0.101 |
| (14.0) | (13.0) | (16.0) | (16.0) | ||||||||
| Lipids | |||||||||||
| Total cholesterol, mg/dL | 202.0 | 204.0 | 202.0 | 198.0 | ＜0.001 | 0.003 | 0.905 | ＜0.001 | 0.629 | ＜0.001 | 0.001 |
| (42.0) | (40.0) | (44.8) | (45.0) | ||||||||
| Triglycerides, mg/dL ‡ | 92.0 | 96.0 | 105.0 | 110.0 | ＜0.001 | ＜0.001 | ＜0.001 | ＜0.001 | ＜0.001 | ＜0.001 | 0.374 |
| (67.0) | (68.0) | (77.0) | (84.0) | ||||||||
| Direct LDL-C, mg/dL | 122.0 | 121.0 | 122.0 | 120.0 | 0.025 | 0.253 | 0.793 | 0.017 | 0.999 | 0.689 | 0.861 |
| (38.0) | (38.0) | (40.0) | (43.0) | ||||||||
| Calculated LDL-C, mg/dL | 123.2 | 122.8 | 122.0 | 118.0 | ＜0.001 | 0.663 | 0.010 | ＜0.001 | 0.070 | ＜0.001 | 0.169 |
| (37.2) | (37.2) | (39.0) | (41.4) | ||||||||
| sdLDL-C, mg/dL ‡ | 30.7 | 33.2 | 35.0 | 34.6 | ＜0.001 | ＜0.001 | ＜0.001 | ＜0.001 | 0.112 | 0.108 | 0.808 |
| (21.2) | (23.0) | (26.8) | (25.5) | ||||||||
| sdLDL-C / LDL-C ratio | 0.25 | 0.27 | 0.28 | 0.28 | ＜0.001 | ＜0.001 | ＜0.001 | ＜0.001 | 0.009 | ＜0.001 | 0.999 |
| (0.14) | (0.15) | (0.17) | (0.18) | ||||||||
| nonHDL-C, mg/dL | 144.0 | 145.0 | 147.0 | 144.0 | 0.223 | ||||||
| (42.0) | (40.0) | (44.0) | (47.0) | ||||||||
| HDL-C, mg/dL | 55.0 | 57.0 | 54.0 | 51.0 | ＜0.001 | ＜0.001 | 0.014 | ＜0.001 | ＜0.001 | ＜0.001 | ＜0.001 |
| (18.0) | (19.0) | (16.0) | (17.0) | ||||||||
| (B) Female Subjects | |||||||||||
| P Value † | |||||||||||
| Non-Smokers ( n = 12,969) | EX1 Smokers ( n = 1,095) | EX2 Smokers ( n = 284) | Current Smokers ( n = 1,030) | ANOVA P Value § | NON vs EX1 | NON vs EX2 | NON vs CUS | EX1 vs EX2 | EX1 vs CUS | EX2 vs CUS | |
| Age, year | 50.0 | 47.0 | 47.0 | 47.0 | ＜0.001 | ＜0.001 | ＜0.001 | ＜0.001 | 0.079 | 0.648 | 0.324 |
| (15.0) | (13.0) | (15.0) | (12.0) | ||||||||
| BMI, kg/m 2 | 20.8 | 21.0 | 21.4 | 20.7 | 0.001 | 0.082 | 0.003 | 0.992 | 0.138 | 0.482 | 0.016 |
| (3.7) | (3.7) | (3.7) | (4.0) | ||||||||
| Systolic blood pressure, mmHg | 107.0 | 106.0 | 107.0 | 105.0 | ＜0.001 | 0.023 | 0.431 | ＜0.001 | 0.999 | 0.120 | 0.488 |
| (21.0) | (19.0) | (22.0) | (19.0) | ||||||||
| Diastolic blood pressure, mmHg | 64.0 | 64.0 | 64.0 | 63.0 | 0.153 | ||||||
| (15.0) | (14.0) | (16.0) | (15.0) | ||||||||
| Glucose metabolism | |||||||||||
| Fasting glucose, mg/dL | 94.0 | 94.0 | 95.0 | 94.0 | 0.637 | ||||||
| (10.0) | (9.0) | (11.0) | (10.0) | ||||||||
| HbA1c, % | 5.5 | 5.5 | 5.4 | 5.5 | ＜0.001 | 0.001 | 0.030 | ＜0.001 | 0.895 | 0.997 | 0.943 |
| (0.4) | (0.4) | (0.4) | (0.4) | ||||||||
| Albumin, mg/dL | 4.2 | 4.2 | 4.2 | 4.2 | 0.531 | ||||||
| (0.3) | (0.3) | (0.3) | (0.3) | ||||||||
| Creatinine, mg/dL | 0.66 | 0.66 | 0.65 | 0.65 | ＜0.001 | 0.999 | 0.035 | 0.002 | 0.078 | 0.050 | 0.890 |
| (0.13) | (0.13) | (0.13) | (0.12) | ||||||||
| ALT, IU/L | 14.0 | 14.0 | 14.0 | 14.0 | 0.814 | ||||||
| (8.0) | (7.0) | (7.8) | (8.0) | ||||||||
| Lipids | |||||||||||
| Total cholesterol, mg/dL | 207.0 | 203.0 | 203.0 | 200.0 | ＜0.001 | 0.044 | 0.636 | ＜0.001 | 0.998 | 0.441 | 0.666 |
| (48.0) | (49.0) | (51.0) | (47.5) | ||||||||
| Triglycerides, mg/dL ‡ | 65.0 | 67.0 | 73.0 | 76.0 | ＜0.001 | 0.070 | 0.006 | ＜0.001 | 0.194 | ＜0.001 | 0.330 |
| (39.0) | (41.0) | (48.8) | (50.3) | ||||||||
| Direct LDL-C, mg/dL | 117.0 | 113.0 | 114.0 | 113.0 | ＜0.001 | 0.001 | 0.844 | 0.011 | 0.819 | 0.988 | 0.911 |
| (42.0) | (43.0) | (43.8) | (45.0) | ||||||||
| Calculated LDL-C, mg/dL | 121.6 | 117.0 | 117.4 | 115.2 | ＜0.001 | ＜0.001 | 0.167 | ＜0.001 | 0.999 | 0.722 | 0.896 |
| (41.1) | (43.6) | (46.6) | (43.5) | ||||||||
| sdLDL-C, mg/dL ‡ | 24.0 | 24.1 | 25.3 | 25.0 | ＜0.001 | 0.781 | 0.014 | ＜0.001 | 0.093 | 0.041 | 0.922 |
| (12.5) | (13.5) | (16.8) | (15.0) | ||||||||
| sdLDL-C / LDL-C ratio | 0.21 | 0.22 | 0.23 | 0.23 | ＜0.001 | ＜0.001 | ＜0.001 | ＜0.001 | 0.053 | 0.001 | 0.999 |
| (0.07) | (0.08) | (0.10) | (0.11) | ||||||||
| nonHDL-C, mg/dL | 137.0 | 132.0 | 133.5 | 132.0 | 0.001 | 0.003 | 0.854 | 0.075 | 0.847 | 0.901 | 0.981 |
| (45.0) | (49.0) | (47.8) | (49.0) | ||||||||
| HDL-C, mg/dL | 69.0 | 69.0 | 67.0 | 66.0 | ＜0.001 | 0.218 | 0.856 | ＜0.001 | 0.364 | ＜0.001 | 0.302 |
| (19.0) | (19.0) | (20.0) | (20.3) | ||||||||
Data are expressed as median (interquartile range).
§ P value for comparison across the groups was determined by one-way analysis of variance. P value ＜0.05 was considered statistically significant.
† P value for comparison between individual groups, using Tukey post-hoc analysis for equally distributed variables and Games-Howell post-hoc analysis for non-equally distributed variables. P value ＜0.001 was considered statistically significant.
‡ Variable was log-transformed prior to formal statistical analysis.
ALT, alanine aminotransferase; BMI, body mass index; CUS, current smokers; EX1, ex-smokers who had quit smoking for ≥ 5 years; EX2, ex-smokers who had quit smoking for ＜5 years; HbA1c, hemoglobin A1c; HDL-C, high-density lipoprotein cholesterol; LDL-C, low-density lipoprotein cholesterol; NON, non-smokers; sdLDL-C, small dense low-density lipoprotein cholesterol