Table 4.
Mediating influence of serum retinol on the associations between major risk factors and overall mortality.
| Mortality risk factor | Multivariate HR (95% CI)a | Proportion (%) of effect due to mediation through retinol | P value for mediation |
|---|---|---|---|
| Obesity | 1.21 (1.13, 1.30) | None | — |
| Intensity of smokingb | 1.28 (1.19, 1.37) | None | — |
| Duration of smokingb | 1.30 (1.21, 1.41) | 2.2 (1.−3.2) | <0.0001 |
| Diabetes mellitus | 1.87 (1.72, 1.03) | 1.2 (0.5−3.1) | 0.016 |
| Alcohol drinkingb | 1.08 (1.01, 1.15) | None | — |
| Physical activity | 0.81 (0.76, 0.85) | None | None |
aCox proportional hazard regression model, adjusted for age, obesity (no: BMI < 30; yes: BMI > = 30), BMI (continuous), years of smoking (quintile), cigarettes smoked per day (quintile), history of diabetes (no or yes, self-reported at baseline), alcohol intake (quintile), physical activity (light or moderate physical activity: no or yes), serum total and HDL cholesterol (continuous), intervention assignment, systolic and diastolic blood pressure (continuous), and history of CVD (no or yes, self-reported at baseline).
bReported HR: quintile 5 (Q5) versus Q1 of major risk factor from the Cox regression model.
Abbreviations: BMI body mass index, CI confidence interval, CVD cardiovascular disease, HDL high-density lipoprotein, HR hazard ratio.