TABLE 4.
Associations between quintile (Q) of fish and long-chain n−3 fatty acids and the relative risk of type 2 diabetes stratified by BMI (in kg/m2) and waist-to-hip ratio (WHR): Shanghai Women's Health Study1
| Food groups | BMI ≤25 | BMI >25 | P for interaction factor | WHR ≤0.85 | WHR >0.85 | P for interaction factor |
| Combined fish and shellfish | 0.02 | |||||
| Q1 | 1.00 | 1.00 | 1.00 | 1.00 | 0.02 | |
| Q2 | 0.79 (0.66, 0.95) | 0.97 (0.85, 1.10) | 0.91 (0.79, 1.05) | 0.92 (0.78, 1.08) | ||
| Q3 | 0.81 (0.67, 0.98) | 0.77 (0.67, 0.90) | 0.74 (0.64,0.87) | 0.84 (0.71, 1.00) | ||
| Q4 | 0.69 (0.56, 0.85) | 0.89 (0.77, 1.03) | 0.79 (0.67, 0.92) | 0.90 (0.75, 1.08) | ||
| Q5 | 0.83 (0.67, 1.03) | 0.84 (0.71, 1.00) | 0.81 (0.68, 0.97) | 0.91 (0.74, 1.12) | ||
| P for trend | 0.03 | 0.02 | <0.01 | 0.16 | ||
| Fish | ||||||
| Q1 | 1.00 | 1.00 | 0.30 | 1.00 | 1.00 | 0.25 |
| Q2 | 0.92 (0.77, 1.10) | 0.98 (0.86, 1.11) | 0.95 (0.83, 1.10) | 0.95 (0.81, 1.11) | ||
| Q3 | 0.81 (0.67, 0.98) | 0.85 (0.73, 0.97) | 0.80 (0.69, 0.93) | 0.87 (0.73, 1.04) | ||
| Q4 | 0.71 (0.58, 0.87) | 0.85 (0.73, 0.98) | 0.74 (0.63, 0.87) | 0.89 (0.74, 1.06) | ||
| Q5 | 0.89 (0.72, 1.10) | 0.86 (0.74, 1.01) | 0.86 (0.73, 1.01) | 0.92 (0.76, 1.12) | ||
| P for trend | 0.02 | 0.02 | <0.01 | 0.13 | ||
| Saltwater fish | ||||||
| Q1 | 1.00 | 1.00 | 0.01 | 1.00 | 1.00 | <0.01 |
| Q2 | 0.90 (0.76, 1.08) | 1.05 (0.92, 1.20) | 0.87 (0.75, 0.99) | 1.17 (1.00, 1.36) | ||
| Q3 | 0.77 (0.63, 0.93) | 0.96 (0.83, 1.11) | 0.79 (0.68, 0.91) | 1.02 (0.86, 1.21) | ||
| Q4 | 0.81 (0.67, 0.98) | 1.05 (0.91, 1.22) | 0.84 (0.72, 0.97) | 1.10 (0.90, 1.28) | ||
| Q5 | 0.72 (0.59, 0.88) | 0.92 (0.79, 1.07) | 0.76 (0.65, 0.89) | 0.93 (0.77, 1.13) | ||
| P for trend | <0.001 | 0.63 | <0.01 | 0.48 | ||
| Freshwater fish | ||||||
| Q1 | 1.00 | 1.00 | 0.46 | 1.00 | 1.00 | 0.97 |
| Q2 | 0.89 (0.74, 1.07) | 1.01 (0.88, 1.15) | 0.92 (0.80, 1.06) | 0.97 (0.82, 1.13) | ||
| Q3 | 0.82 (0.67, 0.99) | 0.82 (0.71, 0.94) | 0.81 (0.70, 0.95) | 0.80 (0.68, 0.95) | ||
| Q4 | 0.94 (0.78, 1.14) | 0.86 (0.74, 0.99) | 0.90 (0.77, 1.05) | 0.89 (0.75, 1.06) | ||
| Q5 | 0.86 (0.71, 1.06) | 0.87 (0.75, 1.01) | 0.84 (0.72, 1.13) | 0.88 (0.73, 1.05) | ||
| P for trend | 0.23 | 0.01 | 0.08 | 0.04 | ||
| Shellfish | ||||||
| Q1 | 1.00 | 1.00 | 0.93 | 1.00 | 1.00 | 0.28 |
| Q2 | 0.95 (0.79, 1.15) | 0.86 (0.76, 0.98) | 0.97 (0.77, 1.02) | 0.89 (0.77, 1.04) | ||
| Q3 | 0.83 (0.68, 1.01) | 0.74 (0.64, 0.85) | 0.79 (0.67, 0.92) | 0.76 (0.64, 0.91) | ||
| Q4 | 0.83 (0.67, 1.01) | 0.75 (0.64, 0.87) | 0.790 (0.67, 0.92) | 0.79 (0.66, 0.96) | ||
| Q5 | 0.90 (0.72, 1.12) | 0.81 (0.69, 0.96) | 0.84 (0.70, 0.99) | 0.91 (0.74, 1.11) | ||
| P for trend | 0.26 | 0.001 | 0.02 | 0.14 | ||
| Long-chain n−3 fatty acids | ||||||
| Q1 | 1.00 | 1.00 | <0.01 | 1.00 | 1.00 | <0.01 |
| Q2 | 0.90 (0.80, 1.00) | 0.93 (0.81, 1.07) | 0.79 (0.64, 0.92) | 1.02 (0.86, 1.20) | ||
| Q3 | 0.84 (0.75, 0.94) | 0.86 (0.74, 0.99) | 0.75 (0.64, 0.88) | 0.98 (0.83, 1.17) | ||
| Q4 | 0.87 (0.77, 0.98) | 1.01 (0.87, 1.17) | 0.79 (0.68, 0.93) | 1.01 (0.84, 1.21) | ||
| Q5 | 0.84 (0.74, 0.95) | 0.91 (0.77, 1.07) | 0.78 (0.66, 0.93) | 0.97 (0.79, 1.18) | ||
| P for trend | <0.01 | 0.51 | 0.01 | 0.75 | ||
1
All values are relative risks; 95% CIs in parentheses. Relative risks were adjusted for age, energy intake (kcal/d), smoking, alcohol consumption, physical activity, income level, educational level, occupation, family history of diabetes, hypertension, and dietary patterns. In addition, the analysis stratified by BMI was adjusted for WHR, and the analysis stratified by WHR was adjusted for BMI.