Table 4. Omega-3 versus placebo (subgroups EPA/DHA).
| Overall effect | Heterogeneity | ||||||
|---|---|---|---|---|---|---|---|
| Outcome | No. of studies | No. of participants | Statistical method | Effect size[95%CI] | P | I2,% | P' |
| Glycemic control | |||||||
| FPG (mmol/L) | 17 | 990 | WMD (IV, Fixed) | 0.181[-0.022,0.385] | 0.081 | 0.0 | 0.964 |
| 1.4≤EPA/DHA≤1.5 [17,18,22,24,26–28,30,32] | 9 | 616 | WMD (IV, Fixed) | 0.103[-0.160,0.366] | 0.444 | 0.0 | 0.972 |
| EPA/DHA>1.5 [13,14,23,25,29] | 5 | 268 | WMD (IV, Fixed) | 0.386[-0.024,0.796] | 0.065 | 0.0 | 0.829 |
| EPA/DHA<1.4 [16,19,20] | 3 | 106 | WMD (IV, Fixed) | 0.157[-0.359,0.673] | 0.551 | 16.2 | 0.303 |
| PPG (mmol/L) | 2 | 42 | WMD (IV, Fixed) | -1.036[-3.280,1.208] | 0.366 | 9.5 | 0.293 |
| EPA/DHA>1.5 [25] | 1 | 26 | WMD (IV, Fixed) | 0.110[-2.988,3.208] | 0.945 | - | - |
| EPA/DHA<1.4 [19] | 1 | 16 | WMD (IV, Fixed) | -2.300[-5.555,0.955] | 0.166 | - | - |
| HbAc1 (%) | 15 | 1179 | WMD (D+L, Random) | -0.050[-0.219,0.119] | 0.565 | 45.7 | 0.028 |
| 1.4≤EPA/DHA≤1.5 [17,18,22,24,28,30,32] | 7 | 580 | WMD (D+L, Random) | 0.067[-0.130,0.264] | 0.503 | 0.0 | 0.779 |
| EPA/DHA>1.5 [14,23,25,29] | 4 | 167 | WMD (D+L, Random) | -0.277[-1.069,0.514] | 0.492 | 66.7 | 0.029 |
| EPA/DHA<1.4 [15,16,19,20] | 4 | 432 | WMD (D+L, Random) | 0.003[-0.071,0.077] | 0.938 | 0.0 | 0.939 |
| INS (pmol/L) | 9 | 588 | WMD (IV, Fixed) | -4.568[-10.943,1.807] | 0.160 | 2.8 | 0.411 |
| 1.4≤EPA/DHA≤1.5 [18,22,24,26–28] | 6 | 500 | WMD (IV, Fixed) | -6.642[-14.239,0.956] | 0.087 | 18.2 | 0.295 |
| EPA/DHA>1.5 [23] | 1 | 22 | WMD (IV, Fixed) | -1.700[-15.419,12.019] | 0.808 | - | - |
| EPA/DHA<1.4 [16,19] | 2 | 66 | WMD (IV, Fixed) | 5.947[-16.599,28.493] | 0.605 | 0.0 | 0.364 |
| Lipid parameters | |||||||
| TG (mmol/L) | 12 | 703 | WMD (IV, Fixed) | -0.243[-0.339,-0.147] | <0.001 | 0.0 | 0.912 |
| 1.4≤EPA/DHA≤1.5 [17,22,24,26,27,30,32] | 7 | 190 | WMD (IV, Fixed) | -0.209[-0.384,-0.033] | 0.020 | 0.0 | 0.986 |
| EPA/DHA>1.5 [13,23,25] | 4 | 187 | WMD (IV, Fixed) | -0.483[-0.736,-0.230] | <0.001 | 0.0 | 0.950 |
| EPA/DHA<1.4 [15] | 1 | 326 | WMD (IV, Fixed) | -0.200[-0.328,-0.072] | 0.002 | - | - |
| TC (mmol/L) | 15 | 874 | WMD (IV, Fixed) | -0.023[-0.120,0.073] | 0.635 | 0.0 | 0.831 |
| 1.4≤EPA/DHA≤1.5 [17,22,24,26,27,30,32] | 7 | 190 | WMD (IV, Fixed) | 0.116[-0.110,0.343] | 0.313 | 0.0 | 0.968 |
| EPA/DHA>1.5 [13,14,23,25,29] | 5 | 268 | WMD (IV, Fixed) | -0.141[-0.321,0.040] | 0.127 | 0.0 | 0.417 |
| EPA/DHA<1.4 [15,16,20] | 3 | 416 | WMD (IV, Fixed) | -0.008[-0.140,0.124] | 0.902 | 0.0 | 0.748 |
| BMI (kg/m2) | 3 | 392 | WMD (IV, Fixed) | 0.055[-0.800,0.909] | 0.900 | 0.0 | 0.947 |
| 1.4≤EPA/DHA≤1.5 [30] | 1 | 44 | WMD (IV, Fixed) | 0.100[-2.394,2.594] | 0.937 | - | - |
| EPA/DHA>1.5 [23] | 1 | 22 | WMD (IV, Fixed) | -0.400[-3.242,2.442] | 0.783 | - | - |
| EPA/DHA<1.4 [15] | 1 | 326 | WMD (IV, Fixed) | 0.100[-0.860,1.060] | 0.838 | - | - |
| Weight (kg) | 6 | 248 | WMD (IV, Fixed) | 0.365[-2.788,3.518] | 0.820 | 0.0 | 1.000 |
| 1.4≤EPA/DHA≤1.5 [17,22,24,27,28,30] | 2 | 140 | WMD (IV, Fixed) | -0.060[-5.243,5.123] | 0.982 | 0.0 | 1.000 |
| EPA/DHA>1.5 [25,29] | 1 | 68 | WMD (IV, Fixed) | 0.358[-4.777,5.493] | 0.891 | 0.0 | 0.867 |
| EPA/DHA< 1.4 [20] | 9 | 40 | WMD (IV, Fixed) | 1.000[-5.271,7.271] | 0.755 | - | - |
Notes: BMI, body mass index; FPG, fast plasma glucose; PPG, postprandial glucose; HbA1c, glycosylated hemoglobin; INS, insulin; TG, Triglyceride; TC, total cholesterol; WMD, weighted mean difference; IV, inverse variance; D+L, DerSimonian & Laird;-, not available.