TABLE 3.
Subgroup analysis for phytoestrogen intake and risk of T2D in studies conducted in women only1
| Subgroups by study characteristics | Number of studies | Participants, n | T2D cases, n | RR (95% CI) |
|---|---|---|---|---|
| Study design | ||||
| Nested case-control | 2 | 7950 | 425 | 0.97 (0.78, 1.20) |
| Cohort | 4 | 186,323 | 8218 | 0.89 (0.81, 0.99) |
| Type of phytoestrogen | ||||
| Isoflavones | 4 | 105,096 | 3128 | 0.88 (0.76, 1.02) |
| Other phytoestrogens | 2 | 89,227 | 5515 | 0.95 (0.86, 1.05) |
| Difference between phytoestrogen intake in | ||||
| highest vs. lowest quantile | ||||
| Median or less (≤5.33-fold) | 3 | 73,037 | 1321 | 0.86 (0.68, 1.10) |
| Higher than median (>5.33-fold) | 3 | 110,832 | 6796 | 0.93 (0.88, 0.99) |
| Location | ||||
| Asia | 3 | 73,087 | 1321 | 0.86 (0.68, 1.10) |
| Other | 3 | 121,236 | 7322 | 0.93 (0.88, 0.99) |
| Age, y | ||||
| Median or less (≤53.35) | 3 | 105,669 | 2827 | 0.87 (0.69, 1.09) |
| Higher than median (>53.35) | 3 | 78,200 | 5290 | 0.93 (0.88, 0.99) |
| BMI, kg/m2 | ||||
| Median or less (≤25.69) | 3 | 39,959 | 2232 | 0.93 (0.86, 0.99) |
| Higher than median (>25.69) | 3 | 143,910 | 5885 | 0.87 (0.74, 1.03) |
1“Study population” indicates studies conducted only in women: investigation performed only among female population, after excluding studies [Muller et al. (14), and Zamora-Ros et al. (15)] that reported overall results for male and female subjects but stated that they tested the interaction term with sex. “Study design”: only prospective cohort and nested case-control studies were included. “Type of phytoestrogen”: “Soy products” estimates were pooled together for soy beans, soy milk, soy flour, and other soy products. “Location”: “Asia” (South Korea, Japan, and 2 studies from China; “Other”: Europe and 2 studies from the United States). T2D, type 2 diabetes.