Table 2.
Multivariable-adjusted hazard ratios and 95% confidence intervals of lung cancer by quintile of serum alpha-tocopherol concentration at baseline and at 3 years among Finnish male smokers in the ATBC Study*
| Serum measure | Event/total person-years of follow-up | Lung cancer incidence rate† | HR (95% CI) |
|---|---|---|---|
| Baseline alpha-tocopherol, range, mg/L | |||
| Q1: <9.5 | 695/66 962 | 10.38 | 1.00 (Ref) |
| Q2: ≥9.5 to <10.9 | 681/72 593 | 9.38 | 0.92 (0.82 to 1.02) |
| Q3: ≥10.9 to <12.3 | 629/71 879 | 8.75 | 0.87 (0.78 to 0.98) |
| Q4: ≥12.3 to <14.2 | 613/75 329 | 8.14 | 0.80 (0.71 to 0.90) |
| Q5: ≥14.2 | 566/73 821 | 7.67 | 0.76 (0.66 to 0.87) |
| Ptrend‡ | <.001 | ||
| 3-Year alpha-tocopherol, range, mg/L | |||
| Q1: <11.4 | 698/67 294 | 10.37 | 1.00 (Ref) |
| Q2: ≥11.4 to <13.6 | 646/74 157 | 8.71 | 0.85 (0.76 to 0.95) |
| Q3: ≥13.6 to <15.9 | 632/72 951 | 8.66 | 0.82 (0.73 to 0.93) |
| Q4: ≥15.9 to <19.0 | 609/74 088 | 8.22 | 0.77 (0.67 to 0.88) |
| Q5: ≥19.0 | 599/72 095 | 8.31 | 0.78 (0.67 to 0.91) |
| Ptrend‡ | .004 | ||
| Mean alpha-tocopherol at baseline and 3 y, range, mg/L | |||
| Q1: <10.8 | 701/67 336 | 10.41 | 1.00 (Ref) |
| Q2: ≥10.8 to <12.5 | 663/73 594 | 9.01 | 0.86 (0.77 to 0.96) |
| Q3: ≥12.5 to <14.1 | 630/72 655 | 8.67 | 0.83 (0.74 to 0.94) |
| Q4: ≥14.1 to <16.3 | 608/74 059 | 8.21 | 0.79 (0.70 to 0.90) |
| Q5: ≥16.3 | 582/72 941 | 7.98 | 0.76 (0.66 to 0.87) |
| Ptrend‡ | <.001 | ||
| Maximum alpha-tocopherol at baseline or 3 y, range, mg/L | |||
| Q1: <11.7 | 708/67 948 | 10.42 | 1.00 (Ref) |
| Q2: ≥11.7 to <13.9 | 635/73 945 | 8.59 | 0.84 (0.75 to 0.94) |
| Q3: ≥13.9 to <16.1 | 626/72 576 | 8.63 | 0.82 (0.73 to 0.93) |
| Q4: ≥16.1 to <19.2 | 622/75 028 | 8.29 | 0.79 (0.69 to 0.90) |
| Q5: ≥19.2 | 593/71 086 | 8.34 | 0.79 (0.68 to 0.92) |
| Ptrend‡ | .008 | ||
Cox proportional hazards regression using follow-up time as the time metric to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) of associations between measures of serum alpha-tocopherol (quintiles) and incidence of lung cancer, and adjusted for age at baseline, body mass index, years of cigarette smoking, number of cigarettes smoked daily, serum total cholesterol concentration, and trial intervention group. ATBC = Alpha-Tocopherol, Beta-Carotene Cancer Prevention; Q = quintile; Ref = referent.
Crude lung cancer incidence rate per 1000 person-years.
Two-sided Ptrend is based on the statistical significance of the coefficient of the quintile variable (median value within each quintile).