Table 3. Omega-3 versus placebo (subgroups study duration).
| Overall effect | Heterogeneity | ||||||
|---|---|---|---|---|---|---|---|
| Outcome | No. of studies | No. of participants | Statistical method | Effect size[95%CI] | P | I2,% | P' |
| Glycemic control | |||||||
| FPG (mmol/L) | 19 | 1022 | WMD (IV, Fixed) | 0.190[-0.011,0.391] | 0.064 | 0.0 | 0.982 |
| Duration > 8 weeks [13,16,18–20,23,29] | 7 | 681 | WMD (IV, Fixed) | 0.190[-0.039,0.419] | 0.104 | 0.0 | 0.556 |
| Duration≤ 8 weeks [14,17,21,22,24–28,30–32] | 12 | 341 | WMD (IV, Fixed) | 0.191[-0.228,0.610] | 0.372 | 0.0 | 0.992 |
| PPG (mmol/L) | 3 | 62 | WMD (IV, Fixed) | -0.005[-1.712,1.702] | 0.995 | 33.9 | 0.220 |
| Duration > 8 weeks [19] | 1 | 16 | WMD (IV, Fixed) | -2.300[-5.555,0.955] | 0.166 | ― | ― |
| Duration≤8 weeks [21] | 2 | 46 | WMD (IV, Fixed) | 0.866[-1.139,2.870] | 0.397 | 0.0 | 0.531 |
| HbAc1 (%) | 17 | 1211 | WMD (D+L, Random) | -0.046[-0.204,0.112] | 0.568 | 38.5 | 0.054 |
| Duration >8 weeks [15,16,18–20,23,29] | 7 | 910 | WMD (D+L, Random) | 0.009[-0.061,0.079] | 0.799 | 0.0 | 0.988 |
| Duration≤8 weeks [14,17,21,22,24,25,28,30–32] | 10 | 301 | WMD (D+L, Random) | -0.081[-0.555,0.394] | 0.739 | 51.6 | 0.029 |
| INS (pmol/L) | 10 | 600 | WMD (D+L, Random) | -5.489[-14.882,3.905] | 0.252 | 38.4 | 0.102 |
| Duration >8 weeks [16,18,19,23] | 4 | 502 | WMD (D+L, Random) | -5.829[-15.011,3.354] | 0.213 | 18.5 | 0.298 |
| Duration≤8 weeks [22,24,26–28,31] | 6 | 98 | WMD (D+L, Random) | -8.948[-27.854,9.957] | 0.354 | 54.0 | 0.054 |
| Lipid parameters | |||||||
| TG (mmol/L) | 14 | 735 | WMD (IV, Fixed) | -0.240[-0.334,-0.147] | <0.001 | 0.0 | 0.812 |
| Duration >8 weeks [13,15,23,29] | 4 | 487 | WMD (IV, Fixed) | -0.249[-0.365,-0.133] | <0.001 | 11.2 | 0.337 |
| Duration≤8 weeks [17,21,22,24–27,30–32] | 10 | 248 | WMD (IV, Fixed) | -0.225[-0.382,-0.068] | 0.005 | 0.0 | 0.832 |
| TC (mmol/L) | 17 | 906 | WMD (IV, Fixed) | -0.019[-0.114,0.076] | 0.690 | 0.0 | 0.855 |
| Duration >8 weeks [13,15,16,20,23] | 6 | 577 | WMD (IV, Fixed) | -0.058[-0.172,0.057] | 0.326 | 0.0 | 0.671 |
| Duration≤8 weeks [14,17,21,22,24–27,31,32] | 11 | 329 | WMD (IV, Fixed) | 0.064[-0.106,0.234] | 0.459 | 0.0 | 0.841 |
| BMI (kg/m2) | 4 | 412 | WMD (IV, Fixed) | 0.060[-0.741,0.861] | 0.883 | 0.0 | 0.991 |
| Duration >8 weeks [15,23] | 2 | 348 | WMD (IV, Fixed) | 0.049[-0.861,0.959] | 0.916 | 0.0 | 0.744 |
| Duration≤8 weeks [30] [21] | 2 | 64 | WMD (IV, Fixed) | 0.100[-1.590,1.790] | 0.908 | 0.0 | 1.000 |
| Weight (kg) | 9 | 248 | WMD (IV, Fixed) | 0.365[-2.788,3.518] | 0.820 | 0.0 | 1.000 |
| Duration >8 weeks [20] [29] | 2 | 82 | WMD (IV, Fixed) | 0.527[-3.793,4.847] | 0.811 | 0.0 | 0.838 |
| Duration≤8 weeks [17,22,24,25,27,28,30] | 7 | 166 | WMD (IV, Fixed) | 0.181[-4.432,4.794] | 0.939 | 0.0 | 1.000 |
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.