Table 2.
Hazard ratios (HRs) and 95% CI for overall and cause-specific mortality by quintile of serum retinol a(we used Cox proportional hazard regression models to estimate HRs and 95% CIs. All reported P-values are 2-sided at type I error rate of 0.05. The Bonferroni corrected P trend value is also presented).
| Causes of mortality | Serum retinol (ug/L) | |||||||
|---|---|---|---|---|---|---|---|---|
| Quintile 1 | Quintile 2 | Quintile 3 | Quintile 4 | Quintile 5 | P for trend | Bonferroni corrected P for trend | Per one SD (130 μg/L) | |
| Overall | ||||||||
| Deaths (n) | 5,036 | 4,825 | 4,640 | 4,588 | 4,708 | |||
| Death rateb | 53.78 | 46.75 | 44.62 | 42.67 | 44.45 | |||
| Age-adjusted HR (95% CI)c | 1.00 | 0.87 (0.84, 0.91) | 0.85 (0.81, 0.88) | 0.82 (0.79, 0.86) | 0.90 (0.87, 0.94) | <0.0001 | <0.0001 | 0.97 (0.96, 0.98) |
| Multivariate HR (95% CI)d | 1.00 | 0.87 (0.83, 0.90) | 0.84 (0.80, 0.87) | 0.80 (0.77, 0.83) | 0.83 (0.80, 0.87) | <0.0001 | <0.0001 | 0.95 (0.94, 0.96) |
| CVD | ||||||||
| Deaths (n) | 2,051 | 1,919 | 1,974 | 1,901 | 2,024 | |||
| Death rateb | 21.90 | 18.59 | 18.98 | 17.68 | 19.11 | |||
| Age-adjusted HR (95% CI)c | 1.00 | 0.86 (0.81, 0.91) | 0.89 (0.84, 0.95) | 0.85 (0.80, 0.90) | 0.97 (0.91, 1.03) | 0.50 | 1.00 | 1.01 (0.99, 1.03) |
| Multivariate HR (95% CI)d | 1.00 | 0.82 (0.77, 0.88) | 0.85 (0.79, 0.90) | 0.77 (0.72, 0.82) | 0.81 (0.76, 0.86) | <0.0001 | <0.0001 | 0.95 (0.93, 0.97) |
| Heart disease | ||||||||
| Deaths (n) | 1,674 | 1,568 | 1,625 | 1,549 | 1,648 | |||
| Death rateb | 17.88 | 15.19 | 15.63 | 14.41 | 15.56 | |||
| Age-adjusted HR (95% CI)c | 1.00 | 0.86 (0.80, 0.92) | 0.90 (0.84,0.97) | 0.85 (0.79, 0.91) | 0.96 (0.90, 1.03) | 0.46 | 1.00 | 1.01 (0.99, 1.03) |
| Multivariate HR (95% CI)d | 1.00 | 0.82 (0.76, 0.88) | 0.85 (0.79, 0.91) | 0.76 (0.71, 0.82) | 0.79 (0.74, 0.85) | <0.0001 | <0.0001 | 0.95 (0.92, 0.97) |
| Stroke | ||||||||
| Deaths (n) | 369 | 347 | 340 | 343 | 365 | |||
| Death rateb | 3.94 | 3.36 | 3.27 | 3.19 | 3.45 | |||
| Age-adjusted HR (95% CI)c | 1.00 | 0.86 (0.74, 0.99) | 0.85 (0.74, 0.99) | 0.84 (0.73, 0.98) | 0.97 (0.84, 1.13) | 0.89 | 1.00 | 1.01 (0.96, 1.06) |
| Multivariate HR (95% CI)d | 1.00 | 0.85 (0.74, 0.99) | 0.84 (0.73, 0.98) | 0.81 (0.69, 0.94) | 0.86 (0.74, 1.01) | 0.084 | 0.76 | 0.98 (0.93, 1.03) |
| Cancer | ||||||||
| Deaths (n) | 1,583 | 1,607 | 1,506 | 1,520 | 1,479 | |||
| Death rateb | 16.90 | 15.57 | 14.48 | 14.14 | 13.96 | |||
| Age-adjusted HR (95% CI)c | 1.00 | 0.93 (0.87, 1.00) | 0.88 (0.82, 0.94) | 0.87 (0.81, 0.94) | 0.90 (0.83, 0.96) | 0.0013 | 0.012 | 0.96 (0.94, 0.99) |
| Multivariate HR (95% CI)d | 1.00 | 0.95 (0.88, 1.01) | 0.90 (0.84, 0.96) | 0.89 (0.83, 0.96) | 0.92 (0.85, 0.99) | 0.016 | 0.14 | 0.97 (0.94, 0.99) |
| Respiratory disease | ||||||||
| Deaths (n) | 554 | 465 | 402 | 399 | 341 | |||
| Death rateb | 5.92 | 4.51 | 3.87 | 3.71 | 3.22 | |||
| Age-adjusted HR (95% CI)c | 1.00 | 0.77 (0.68, 0.87) | 0.67 (0.59, 0.76) | 0.66 (0.58, 0.76) | 0.62 (0.54, 0.71) | <0.0001 | <0.0001 | 0.83 (0.79, 0.87) |
| Multivariate HR (95% CI)d | 1.00 | 0.82 (0.73, 0.93) | 0.74 (0.65, 0.84) | 0.74 (0.65, 0.85) | 0.68 (0.59, 0.78) | <0.0001 | <0.0001 | 0.88 (0.84, 0.93) |
| Diabetes mellitus | ||||||||
| Deaths (n) | 24 | 17 | 21 | 30 | 27 | |||
| Death rateb | 0.26 | 0.16 | 0.20 | 0.28 | 0.25 | |||
| Age-adjusted HR (95% CI)c | 1.00 | 0.63 (0.34, 1.18) | 0.78 (0.44, 1.41) | 1.09 (0.64, 1.87) | 1.04 (0.60, 1.81) | 0.36 | 1.00 | 1.08 (0.90, 1.30) |
| Multivariate HR (95% CI)d | 1.00 | 0.64 (0.34, 1.19) | 0.79 (0.44, 1.43) | 1.00 (0.57, 1.73) | 0.88 (0.49, 1.56) | 0.85 | 1.00 | 1.02 (0.85, 1.23) |
| Injuries and accidents | ||||||||
| Deaths (n) | 256 | 262 | 214 | 244 | 279 | |||
| Death rateb | 2.73 | 2.54 | 2.06 | 2.27 | 2.63 | |||
| Age-adjusted HR (95% CI)c | 1.00 | 0.93 (0.78, 1.11) | 0.76 (0.63, 0.91) | 0.84 (0.71, 1.01) | 0.98 (0.83, 1.17) | 0.83 | 1.00 | 0.99 (0.94, 1.05) |
| Multivariate HR (95% CI)d | 1.00 | 0.94 (0.79,1.12) | 0.76 (0.63, 0.92) | 0.83 (0.69, 1.00) | 0.91 (0.76, 1.09) | 0.26 | 1.00 | 0.99 (0.93, 1.05) |
| Other causes | ||||||||
| Deaths (n) | 568 | 555 | 523 | 494 | 558 | |||
| Death rateb | 6.07 | 5.38 | 5.03 | 4.59 | 5.27 | |||
| Age-adjusted HR (95% CI)c | 1.00 | 0.87 (0.77, 0.98) | 0.81 (0.72, 0.91) | 0.75 (0.66, 0.85) | 0.91 (0.81, 1.02) | 0.053 | 0.48 | 0.96 (0.92, 1.00) |
| Multivariate HR (95% CI)d | 1.00 | 0.87 (0.77, 0.98) | 0.80 (0.71, 0.90) | 0.73 (0.64, 0.82) | 0.83 (0.74, 0.94) | 0.0011 | 0.01 | 0.92 (0.88, 0.96) |
Abbreviations: BMI body mass index, CI confidence interval, CVD cardiovascular disease, HDL high-density lipoprotein, HR hazard ratios, SD standard deviation
aCause of death was missing for 47 subjects.
bCrude death rate per 1000 person-years.
cAdjusted for age. P value for trend: based on statistical significance of the coefficient of the quintile variable (median value within each quintile).
dAdjusted for age, BMI, serum total and serum HDL cholesterol, cigarettes smoked per day, years of smoking, alcohol intake, intervention assignment, systolic and diastolic blood pressure, history of CVD, and history of diabetes.