Table 2.
Subgroup analysis of MetS for the highest vs. lowest dietary vitamin E level category.
| Stratification | Number of studies | Pooled RR | 95% CI | P value | Heterogeneity |
|---|---|---|---|---|---|
| All studies | 10 | 0.92 | 0.85, 1.00 | P = 0.04 | P < 0.001; I2 = 67% |
| Adjustment of BMI | |||||
| Adjusted | 5 | 0.75 | 0.59, 0.94 | P = 0.01 | P = 0.02; I2 = 61% |
| Unadjusted | 5 | 0.99 | 0.93, 1.06 | P = 0.79 | P = 0.03; I2 = 58% |
| Adjustment of physical activity | |||||
| Adjusted | 7 | 0.76 | 0.61, 0.95 | P = 0.02 | P = 0.004; I2 = 63% |
| Unadjusted | 3 | 1 | 0.98, 1.02 | P = 0.98 | P = 0.18; I2 = 38% |
| Adjustment of energy intake | |||||
| Adjusted | 5 | 0.86 | 0.76, 0.97 | P = 0.01 | P = 0.17; I2 = 34% |
| Unadjusted | 5 | 0.96 | 0.88, 1.05 | P = 0.42 | P < 0.001; I2 = 76% |
| Adjustment for vitamin E supplement | |||||
| Adjusted | 3 | 0.8 | 0.64, 1.01 | P = 0.06 | P = 0.12; I2 = 48% |
| Unadjusted | 7 | 0.94 | 0.87, 1.02 | P = 0.14 | P < 0.001; I2 = 70% |
| Study design | |||||
| Cross-sectional | 9 | 0.93 | 0.86, 1.01 | P = 0.10 | P < 0.001; I2 = 67% |
| Cohort | 1 | 0.76 | 0.56, 1.03 | / | / |