Table 1. Characteristics of study participants by age-specific tooth loss quartile in the Nutrition Intervention Trials Cohort, Linxian, PRC, 1986–2016.
| Age-specific tooth loss quartilea | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| I | II | III | IV | ||||||||
| Total | No. (%) | No. (%) | No. (%) | No. (%) | |||||||
| Incident liver cancer | |||||||||||
| Yes | 370 | (1.1) | 114 | (1.1) | 92 | (1.3) | 64 | (0.9) | 100 | (1.2) | |
| No | 32319 | (98.9) | 10210 | (98.9) | 6959 | (98.7) | 6689 | (99.1) | 8461 | (98.8) | |
| Chronic liver disease mortality | |||||||||||
| Yes | 408 | (1.2) | 120 | (1.2) | 95 | (1.3) | 87 | (1.3) | 106 | (1.2) | |
| No | 32281 | (98.8) | 10204 | (98.8) | 6956 | (98.7) | 6666 | (98.7) | 8455 | (98.8) | |
| Age at randomization | |||||||||||
| <44 | 7911 | (24.2) | 3834 | (37.1) | 588 | (8.3) | 1740 | (25.8) | 1749 | (20.4) | |
| 45–49 | 5445 | (16.7) | 1690 | (16.4) | 1283 | (18.2) | 958 | (14.2) | 1514 | (17.7) | |
| 50–54 | 5968 | (18.3) | 1537 | (14.9) | 1634 | (23.2) | 1140 | (16.9) | 1657 | (19.4) | |
| 55–59 | 5687 | (17.4) | 1401 | (13.6) | 1556 | (22.1) | 1139 | (16.9) | 1591 | (18.6) | |
| 60–54 | 4565 | (14.0) | 1099 | (10.6) | 1178 | (16.7) | 1016 | (15.0) | 1272 | (14.9) | |
| ≥65 | 3113 | (9.5) | 763 | (7.4) | 812 | (11.5) | 760 | (11.3) | 778 | (9.1) | |
| Sex | |||||||||||
| Male | 14541 | (44.5) | 5522 | (53.5) | 3397 | (48.2) | 2726 | (40.4) | 2896 | (33.8) | |
| Female | 18148 | (55.5) | 4802 | (46.5) | 3654 | (51.8) | 4027 | (59.6) | 5665 | (66.2) | |
| BMI (kg/m2) | |||||||||||
| < 18.50 | 2339 | (7.2) | 493 | (4.8) | 422 | (6.0) | 545 | (8.1) | 879 | (10.3) | |
| 18.50–22.99 | 21474 | (65.7) | 6667 | (64.6) | 4689 | (66.5) | 4424 | (65.5) | 5694 | (66.5) | |
| 23.00–27.49 | 8130 | (24.9) | 2902 | (28.1) | 1750 | (24.8) | 1636 | (24.2) | 1842 | (21.5) | |
| ≥ 27.5 | 743 | (2.3) | 262 | (2.5) | 187 | (2.7) | 148 | (2.2) | 146 | (1.7) | |
| Missing | 0 | 0 | 3 | 0 | 0 | ||||||
| Education | |||||||||||
| No formal school | 13195 | (40.4) | 2980 | (28.9) | 3144 | (44.6) | 2921 | (43.3) | 4150 | (48.5) | |
| 1–5 years of education | 10137 | (31.0) | 3575 | (34.6) | 2180 | (30.9) | 1997 | (29.6) | 2385 | (27.9) | |
| Completed primary school | 3415 | (10.4) | 1473 | (14.3) | 549 | (7.8) | 690 | (10.2) | 703 | (8.2) | |
| Middle school or higher | 2857 | (8.7) | 1512 | (14.6) | 357 | (5.1) | 525 | (7.8) | 434 | (5.1) | |
| Other | 3080 | (9.4) | 784 | (7.6) | 790 | (11.2) | 619 | (9.2) | 887 | (10.4) | |
| Missing | 0 | 0 | 2 | 1 | 2 | ||||||
| Cigarette smoking | |||||||||||
| Never | 22915 | (70.1) | 6886 | (66.7) | 4729 | (67.1) | 4848 | (71.8) | 6452 | (75.4) | |
| Former | 647 | (2.0) | 238 | (2.3) | 164 | (2.3) | 116 | (1.7) | 129 | (1.5) | |
| Current | 9126 | (27.9) | 3200 | (31.0) | 2158 | (30.6) | 1789 | (26.5) | 1979 | (23.1) | |
| Missing | 0 | 0 | 0 | 0 | 1 | ||||||
| Alcohol use | |||||||||||
| Yes | 7509 | (23.0) | 2826 | (27.4) | 1604 | (22.8) | 1498 | (22.2) | 1581 | (18.5) | |
| No | 25179 | (77.0) | 7498 | (72.6) | 5446 | (77.2) | 5255 | (77.8) | 6980 | (81.5) | |
| Missing | 0 | 0 | 1 | 0 | 0 | ||||||
| Study trial | |||||||||||
| General Population | 29399 | (89.9) | 9638 | (93.4) | 6467 | (91.7) | 6028 | (89.3) | 7266 | (84.9) | |
| Dysplasia | 3290 | (10.1) | 686 | (6.6) | 584 | (8.3) | 725 | (10.7) | 1295 | (15.1) | |
| HBV/HCV statusb | |||||||||||
| anti-HBc(+) | 1048 | (63.7) | 320 | (65.6) | 233 | (59.6) | 215 | (64.4) | 280 | (65.0) | |
| HBsAg(+) | 214 | (13.0) | 75 | (15.4) | 39 | (10.0) | 45 | (13.5) | 55 | (12.8) | |
| anti-HCV(+) | 160 | (9.7) | 62 | (12.7) | 32 | (8.2) | 20 | (6.0) | 46 | (10.7) | |
BMI = body mass index; anti-HBc = antibody to hepatitis B virus core antigen; HBsAg = hepatitis B virus surface antigen; anti-HCV = antibody to HCV
aAge-specific quartiles of tooth loss were estimated using loess regression
bDetermined among 1644 patients free of liver cancer and chronic liver disease mortality selected in two case-controls studies nested in this population