Table 1.
Distribution of baseline characteristics and tea drinking habits by liver cancer status (SWHS, 1996–2016)
| Characteristicsa | All subjects (N=71841) | Non-cases (N=71588) | Cases (N=253) | P valueb |
|---|---|---|---|---|
| Age at study enrollment (years old) | 52.50 ± 9.06 | 52.50 ± 9.06 | 58.49 ± 8.34 | <0.001 |
| Education | <0.001 | |||
| Elementary school or less | 15396 (21.43) | 15290 (21.36) | 106 (41.90) | |
| Middle school | 46821 (65.17) | 46698 (65.23) | 123 (48.62) | |
| College or above | 9624 (13.40) | 9600 (13.41) | 24 (9.49) | |
| Incomec | 0.010 | |||
| Low | 39039 (54.34) | 38888 (54.32) | 151 (59.68) | |
| Middle | 20211 (28.13) | 20135 (28.13) | 76 (30.04) | |
| High | 12591 (17.53) | 12565 (17.55) | 26 (10.28) | |
| Ever cigarette smoker | 1979 (2.75) | 1969 (2.75) | 10 (3.95) | 0.244 |
| Ever alcohol drinker | 1606 (2.24) | 1602 (2.24) | 4 (1.58) | 0.481 |
| Postmenopausal | 35059 (48.80) | 34865 (48.70) | 194 (76.68) | <0.001 |
| Oral contraceptive use | 14649 (20.39) | 14592 (20.40) | 57 (22.53) | 0.398 |
| History of chronic hepatitis | 1836 (2.56) | 1801 (2.52) | 35 (13.83) | <0.001 |
| History of cholelithiasis | 7976 (11.10) | 7924 (11.07) | 52 (20.55) | <0.001 |
| History of type 2 diabetes mellitus | 3075 (4.28) | 3050 (4.26) | 25 (9.88) | <0.001 |
| Family history of liver cancer | 2356 (3.28) | 2330 (3.25) | 26 (10.28) | <0.001 |
| Body mass index (kg/m2) | 24.01 ± 3.42 | 24.01 ± 3.42 | 25.05 ± 3.79 | 0.089 |
| Total physical activity (MET-hours/week) | 106.65 ± 45.05 | 106.65 ± 45.06 | 106.58 ± 48.44 | <0.001 |
| Total energy (kcal/day) | 1673.70 ± 393.84 | 1631.56 ± 392.64 | 1673.55 ± 393.84 | 0.981 |
| Carbohydrate (g/day) | 285.18 ± 66.93 | 285.19 ± 66.94 | 281.95 ± 66.63 | 0.441 |
| Protein (g/day) | 67.01 ± 20.66 | 67.02 ± 20.66 | 63.58 ± 20.34 | 0.008 |
| Fat (g/day) | 29.33 ± 13.04 | 29.34 ± 13.04 | 27.61 ± 13.19 | 0.036 |
| Vitamin C (g/day) | 90.74 ± 48.85 | 90.77 ± 48.87 | 84.09 ± 44.05 | 0.017 |
| Red meat (g/day) | 50.87 ± 36.13 | 50.89 ± 36.13 | 46.13 ± 36.64 | 0.037 |
| Poultry (g/day) | 15.27 ± 17.70 | 15.27 ± 17.69 | 13.70 ± 18.36 | 0.157 |
| Fish (g/day) | 50.56 ± 44.53 | 50.59 ± 44.54 | 42.90 ± 42.04 | 0.006 |
| Fruits (g/day) | 295.63 ± 168.87 | 295.65 ± 168.90 | 291.13 ± 159.29 | 0.671 |
| Vegetables (g/day) | 264.20 ± 178.96 | 264.35 ± 179.04 | 220.62 ± 149.23 | <0.001 |
| Tea drinking habits | ||||
| Never drinker | 51261 (71.35) | 51063 (71.33) | 198 (78.26) | 0.015 |
| Current drinker | 20580 (28.65) | 20525 (28.67) | 55 (21.74) | 0.015 |
| Age of starting regular tea consumption (years old) | 33.43 ± 11.87 | 33.41 ± 11.86 | 40.16 ± 15.39 | 0.002 |
| Duration of tea consumption (years) | 17.31 ± 11.75 | 17.30 ± 11.75 | 17.86 ± 13.85 | 0.728 |
| Intensity of tea consumption (g/month) | 135.01 ± 96.57 | 135.04 ± 96.51 | 125.27 ± 119.04 | 0.546 |
| Cumulative consumption of tea (kg) | 29.96 ± 34.62 | 29.96 ± 34.60 | 26.87 ± 41.96 | 0.587 |
a
Continuous variables were displayed as means ± standard deviations; Categorical variables were displayed as numbers (percentages)
b
Continuous variables were compared using t-tests and categorical variables were compared using χ2 tests.
c
Defined as low: <¥20,000 per family per year; middle: ¥20,000–39,999 per family per year; high: ≥¥30,000 per family per year.