Table 2.
Subgroup analysis conducted to evaluate the hypoglycemic effect of resveratrol.
| Subgroup | No. of Trials | Effect Size | 95% CI | p Value | Heterogeneity (I2) | p Value for I2 |
|---|---|---|---|---|---|---|
| Glucose | ||||||
| Resveratrol dosage (I2 = 76%; p = 0.01) | ||||||
| <500 mg/day | 13 | −5.40 | −11.29, 0.49 | 0.07 | 97% | 0.00001 |
| 500–1000 mg/day | 13 | −7.54 | −12.29, −2.79 | 0.002 | 89% | 0.00001 |
| >1000 mg/day | 6 | 0.82 | −2.78, 4.42 | 0.66 | 51% | 0.00001 |
| Health status (I2 = 91%; p = 0.0008) | ||||||
| With T2DM | 15 | −13.36 | −21.09, −5.63 | 0.0007 | 96% | 0.00001 |
| Without T2DM | 17 | 0.18 | −1.52, 1.89 | 0.83 | 67% | 0.0001 |
| Duration (I2 = 0%; p = 0.89) | ||||||
| <3 months | 15 | −5.29 | −9.20, −1.39 | 0.008 | 81% | 0.00001 |
| ≥3 months | 17 | −4.83 | −9.75, 0.09 | 0.05 | 96% | 0.00001 |
| Age (I2 = 66%; p = 0.05) | ||||||
| <45 years | 6 | 0.08 | −4.08, −4.24 | 0.97 | 79% | 0.0002 |
| 45–59 years | 16 | −11.04 | −19.0, −3.07 | 0.007 | 96% | 0.00001 |
| ≥60 years | 10 | −2.06 | −4.39, 0.27 | 0.08 | 73% | 0.0001 |
| Insulin | ||||||
| Resveratrol dosage (I2 = 0%; p = 0.44) | ||||||
| <500 mg/day | 9 | −1.43 | −2.53, −0.32 | 0.01 | 90% | 0.00001 |
| 500–1000 mg/day | 12 | −0.78 | −1.85, 0.30 | 0.16 | 83% | 0.00001 |
| >1000 mg/day | 5 | −1.23 | −1.90, −0.57 | 0.03 | 73% | 0.006 |
| Health status (I2 = 0%; p = 0.57) | ||||||
| With T2DM | 12 | −0.94 | −1.62, −0.25 | 0.007 | 77% | 0.00001 |
| Without T2DM | 14 | −1.39 | −2.80, 0.01 | 0.05 | 91% | 0.00001 |
| Duration (I2 = 0%; p = 0.38) | ||||||
| <3 months | 13 | −0.93 | −1.53, −0.33 | 0.002 | 69% | 0.0001 |
| ≥3 months | 13 | −1.65 | −3.15, −0.16 | 0.03 | 93% | 0.00001 |
| Age (I2 = 42%; p = 0.18) | ||||||
| <45 years | 5 | −3.60 | −7.65, 0.46 | 0.08 | 96% | 0.00001 |
| 45–59 years | 13 | −0.97 | −1.82, −0.12 | 0.02 | 82% | 0.00001 |
| ≥60 years | 8 | −0.32 | −1.01, 0.36 | 0.35 | 57% | 0.02 |
| HbA1c | ||||||
| Resveratrol dosage (I2 = 0%; p = 0.56) | ||||||
| <500 mg/day | 7 | −0.20 | −0.42, 0.02 | 0.08 | 99% | 0.00001 |
| 500–1000 mg/day | 8 | −0.06 | −0.21, 0.10 | 0.48 | 69% | 0.002 |
| >1000 mg/day | 2 | −0.25 | −1.18, 0.69 | 0.61 | 68% | 0.08 |
| Health status (I2 = 87%; p = 0.005) | ||||||
| With T2DM | 12 | −0.22 | −0.40, −0.04 | 0.02 | 97% | 0.00001 |
| Without T2DM | 5 | 0.05 | −0.01, 0.10 | 0.11 | 0% | 0.78 |
| Duration (I2 = 0%; p = 0.38) | ||||||
| <3 months | 9 | 0.02 | −0.08, 0.13 | 0.66 | 64% | 0.004 |
| ≥3 months | 8 | −0.29 | −0.50, −0.08 | 0.006 | 98% | 0.00001 |
| Age (I2 = 85%; p = 0.001) | ||||||
| <45 years | 1 | 0.05 | −0.04, 0.14 | 0.29 | --- | --- |
| 45–59 years | 9 | −0.34 | −0.54, −0.13 | 0.002 | 98% | 0.00001 |
| ≥60 years | 6 | 0.07 | 0, 0.15 | 0.05 | 0 | 0.48 |
| HOMA-IR | ||||||
| Resveratrol dosage (I2 = 0%; p = 0.62) | ||||||
| <500 mg/day | 11 | −0.22 | −0.55, 0.11 | 0.19 | 57% | 0.01 |
| 500–1000 mg/day | 12 | −0.60 | −1.44, 0.24 | 0.16 | 97% | 0.00001 |
| >1000 mg/day | 5 | −0.22 | −0.74, 0.30 | 0.42 | 46% | 0.11 |
| Health status (I2 = 64%; p = 0.10) | ||||||
| With T2DM | 12 | −0.83 | −1.68, −0.02 | 0.04 | 96% | 0.00001 |
| Without T2DM | 16 | −0.08 | −0.33, 0.17 | 0.54 | 55% | 0.004 |
| Duration (I2 = 0%; p = 0.83) | ||||||
| <3 months | 14 | −0.36 | −1.11, 0.39 | 0.35 | 96% | 0.00001 |
| ≥3 months | 14 | −0.45 | −0.91, 0.00 | 0.05 | 83% | 0.00001 |
| Age (I2 = 0%; p = 0.70) | ||||||
| <45 years | 5 | −0.57 | −1.19, 0.04 | 0.07 | 68% | 0.01 |
| 45–59 years | 14 | −0.39 | −1.25, 0.47 | 0.38 | 96% | 0.00001 |
| ≥60 years | 9 | −0.28 | −0.60, 0.03 | 0.08 | 55% | 0.02 |
Abbreviations: CI, confidence interval; HbA1c, glycated hemoglobin; HOMA-IR, insulin resistance (homeostatic model); and T2DM, type 2 diabetes mellitus.