Table 2.
Subgroup analysis for the effect of anthocyanin on high-density lipoprotein-cholesterol.
| Subgroup | Effect size | I2 2 (%) | P-value3 | |
|---|---|---|---|---|
| K 1 | (95% CI) | |||
| Overall | 49 | 0.42 (0.20, 0.65) | 81 | |
| Study design | ||||
| Parallel study | 41 | 0.52 (0.25, 0.79) | 83 | <0.001 |
| Crossover study | 8 | −0.04 (−0.20, 0.12) | 0 | |
| Study duration | ||||
| <8 weeks | 24 | 0.59 (0.18, 0.99) | 85 | 0.220 |
| ≥8 weeks | 25 | 0.30 (0.08, 0.51) | 75 | |
| Cholesterol level 4 | ||||
| Normal (<200 mg/dL) | 18 | 1.00 (0.42, 1.57) | 91 | 0.020 |
| Higher (≥ 200 mg/dL) | 30 | 0.19 (0.06, 0.31) | 51 | |
| Study area | ||||
| East | 20 | 0.80 (0.41, 1.19) | 85 | 0.007 |
| West | 29 | 0.17 (−0.06, 0.40) | 72 | |
| Participant's age | ||||
| <40 years old | 11 | 1.30 (0.54, 2.05) | 91 | 0.007 |
| ≥40 years old | 38 | 0.21 (0.07, 0.35) | 68 | |
| No. of participants | ||||
| <50 | 19 | 0.77 (0.27, 1.27) | 86 | 0.052 |
| ≥50 | 30 | 0.24 (0.06, 0.42) | 75 | |
| Anthocyanin dosage | ||||
| <50 mg/day | 10 | 0.54 (−0.06, 1.14) | 83 | 0.099 |
| ≥50 and <350 mg/day | 30 | 0.50 (0.18, 0.81) | 85 | |
| ≥350 mg/day | 9 | 0.14 (−0.05, 0.32) | 0 | |
| Formula | ||||
| Low processing | 20 | 0.15 (0.02, 0.27) | 79 | 0.194 |
| High processing | 29 | 0.54 (0.26, 0.83) | 81 | |
| Risk of bias | ||||
| Low risk | 42 | 0.51 (0.25, 0.77) | 83 | 0.002 |
| High risk | 7 | 0.01(−0.17, 0.20) | 0 | |
1Number of studies combined. 2Overall test for heterogeneity within subgroups by the random effects model. 3Test for subgroup difference by random effect model. 4Excluding one study in which total cholesterol level was not presented at the baseline.