TABLE 3.
Subgroup analyses of green tea extract supplementation on some cardiovascular risk factors in adults.
| Number of studies | WMD (95% CI) | P-value | Heterogeneity | ||
| P heterogeneity | I2 | ||||
| Subgroup analyses of green tea extract supplementation on TG (mg/dL) | |||||
| Overall effect | 40 | −5.31 (−12.32, 1.68) | 0.137 | <0.001 | 89.0% |
| Baseline BMI (kg.m–2) | |||||
| Normal weight (18.5-24.9) | 6 | −3.29 (−10.06, 3.47) | 0.340 | 0.572 | 0.0% |
| Overweight (25-29.9) | 20 | −6.29 (−15.86, 3.26) | 0.197 | <0.001 | 87.0% |
| Obese (≥30) | 11 | −3.38 (−17.53, 10.76) | 0.639 | <0.001 | 88.5% |
| Trial duration (week) | |||||
| ≤12 | 19 | 2.23 (−6.11, 10.57) | 0.600 | <0.001 | 81.0% |
| >12 | 21 | −12.61 (−22.03, −3.19) | 0.009 | <0.001 | 87.4% |
| Intervention dose (mg/day) | |||||
| <1,000 | 29 | −7.76 (−15.98, 0.44) | 0.064 | <0.001 | 86.8% |
| ≥1,000 | 11 | 1.63 (−13.14, 16.41) | 0.828 | <0.001 | 91.8% |
| Sex | |||||
| Female | 14 | 0.15 (−6.86, 7.18) | 0.965 | <0.001 | 71.9% |
| Both | 21 | −12.33 (−21.23, −3.43) | 0.007 | <0.001 | 77.3% |
| Male | 5 | 5.50 (−11.93, 22.95) | 0.536 | <0.001 | 80.1% |
| T2DM status | |||||
| Non-T2DM | 33 | −3.92 (−11.42, 3.57) | 0.305 | <0.001 | 89.7% |
| T2DM patients | 7 | −14.83 (−31.27, 1.60) | 0.077 | 0.059 | 50.5% |
| Baseline TG | |||||
| <150 | 26 | −2.55 (−9.58, 4.47) | 0.476 | <0.001 | 86.8% |
| ≥150 | 13 | −12.33 (−28.07, 3.40) | 0.125 | <0.001 | 82.7% |
| Subgroup analyses of green tea extract supplementation on TC (mg/dL) | |||||
| Overall effect | 36 | −7.62 (−10.51, −4.73) | <0.001 | <0.001 | 90.9% |
| Baseline BMI (kg.m–2) | |||||
| Normal weight (18.5-24.9) | 6 | −10.44 (−21.67, 0.77) | 0.068 | <0.001 | 88.3% |
| Overweight (25-29.9) | 17 | −9.27 (−14.12, −4.41) | <0.001 | <0.001 | 83.4% |
| Obese (≥30) | 10 | −2.28 (−5.11, 0.54) | 0.113 | <0.001 | 75.1% |
| Trial duration (week) | |||||
| ≤12 | 20 | −5.80 (−9.06, −2.54) | <0.001 | <0.001 | 88.6% |
| >12 | 16 | −10.90 (−16.78, −5.02) | <0.001 | <0.001 | 89.5% |
| Intervention dose (mg/day) | |||||
| <1000 | 26 | −7.48 (−10.77, −4.19) | <0.001 | <0.001 | 91.4% |
| ≥1000 | 10 | −7.43 (−14.90, 0.04) | 0.051 | <0.001 | 87.0% |
| Sex | |||||
| Female | 14 | −4.69 (−8.60, −0.78) | 0.019 | <0.001 | 64.5% |
| Both | 17 | −11.17 (−16.61, −5.74) | <0.001 | <0.001 | 95.2% |
| Male | 5 | −1.39 (−4.53, 1.75) | 0.387 | 0.328 | 13.6% |
| T2DM status | |||||
| Non-T2DM | 29 | −7.20 (−10.22, −4.18) | <0.001 | <0.001 | 90.2% |
| T2DM patients | 7 | −9.90 (−18.70, −1.10) | 0.027 | <0.001 | 82.8% |
| Baseline TC (mg/dL) | |||||
| <200 | 14 | −2.64 (−5.36, 0.07) | 0.057 | 0.010 | 53.2% |
| ≥200 | 22 | −10.64 (−15.53, −5.75) | <0.001 | <0.001 | 92.6% |
| Subgroup analyses of green tea extract supplementation on LDL (mg/dL) | |||||
| Overall effect | 34 | −5.80 (−8.30, −3.30) | <0.001 | <0.001 | 90.5% |
| Baseline BMI (kg.m–2) | |||||
| Normal weight (18.5-24.9) | 4 | −3.49 (−7.79, 0.80) | 0.111 | 0.458 | 0.0% |
| Overweight (25-29.9) | 17 | −8.40 (−12.45, −4.34) | <0.001 | <0.001 | 84.5% |
| Obese (≥30) | 11 | −2.91 (−6.84, 1.00) | 0.145 | <0.001 | 93.2% |
| Trial duration (week) | |||||
| ≤12 | 18 | −3.59 (−6.08, −1.10) | 0.005 | <0.001 | 84.5% |
| >12 | 16 | −10.05 (−16.61, −3.49) | 0.003 | <0.001 | 92.4% |
| Intervention dose (mg/day) | |||||
| <1000 | 26 | −5.21 (−8.08, −2.34) | <0.001 | <0.001 | 90.2% |
| ≥1000 | 8 | −7.41 (−11.74, −3.08) | 0.001 | <0.001 | 75.3% |
| Sex | |||||
| Female | 13 | −4.22 (−9.41, 0.97) | 0.112 | <0.001 | 86.3% |
| Both | 17 | −5.99 (−9.51, −2.47) | 0.001 | <0.001 | 84.6% |
| Male | 4 | −16.25 (−34.21, 1.70) | 0.076 | <0.001 | 97.0% |
| T2DM status | |||||
| Non-T2DM | 28 | −6.32 (−9.09, −3.56) | <0.001 | <0.001 | 92.0% |
| T2DM patients | 6 | −2.66 (−7.78, 2.44) | 0.307 | 0.146 | 39.0% |
| Baseline LDL (mg/dL) | |||||
| <100 | 3 | −5.38 (−7.70, −3.07) | <0.001 | 0.757 | 0.0% |
| ≥100 | 30 | −6.01 (−8.80, −3.21) | <0.001 | <0.001 | 91.3% |
| Subgroup analyses of green tea extract supplementation on HDL (mg/dL) | |||||
| Overall effect | 34 | 1.85 (0.87, 2.84) | 0.010 | <0.001 | 94.4% |
| Baseline BMI (kg.m–2) | |||||
| Normal weight (18.5-24.9) | 5 | 3.70 (−1.81, 9.22) | 0.188 | <0.001 | 91.2% |
| Overweight (25-29.9) | 16 | 1.07 (−1.44, 3.59) | 0.405 | <0.001 | 92.2% |
| Obese (≥30) | 11 | 1.66 (0.53, 2.78) | 0.004 | <0.001 | 93.1% |
| Trial duration (week) | |||||
| ≤12 | 18 | 0.73 (−0.02, 1.68) | 0.126 | <0.001 | 87.7% |
| >12 | 16 | 2.96 (0.61, 5.30) | 0.013 | <0.001 | 93.0% |
| Intervention dose (mg/day) | |||||
| <1000 | 25 | 1.72 (0.73, 2.70) | 0.001 | <0.001 | 91.3% |
| ≥1000 | 9 | 1.82 (−1.98, 4.62) | 0.348 | <0.001 | 95.3% |
| Sex | |||||
| Female | 13 | 1.63 (0.15, 3.11) | 0.030 | <0.001 | 80.1% |
| Both | 16 | 2.79 (−0.09, 5.67) | 0.058 | <0.001 | 95.9% |
| Male | 5 | −0.48 (−2.37, 1.39) | 0.611 | 0.012 | 68.7% |
| T2DM status | |||||
| Non-T2DM | 28 | 2.16 (1.07, 3.26) | <0.001 | <0.001 | 94.5% |
| T2DM patients | 6 | 0.11 (−1.24, 1.48) | 0.866 | 0.486 | 0.0% |
| Baseline HDL (mg/dL) | |||||
| >50 | 18 | 2.40 (1.14, 3.67) | <0.001 | <0.001 | 95.3% |
| ≥50 | 15 | 1.30 (−0.89, 3.49) | 0.246 | <0.001 | 87.8% |
| Subgroup analyses of green tea extract supplementation on FBS (mg/dL) | |||||
| Overall effect | 44 | −1.67 (−2.58, −0.75) | <0.001 | <0.001 | 72.2% |
| Baseline BMI (kg.m–2) | |||||
| Normal weight (18.5-24.9) | 3 | 0.37 (−3.54, 4.29) | 0.851 | 0.074 | 61.6% |
| Overweight (25-29.9) | 22 | −1.61 (−2.95, −0.28) | 0.018 | 0.099 | 29.2% |
| Obese (≥30) | 15 | −0.90 (−1.85, 0.04) | 0.060 | <0.001 | 69.5% |
| Trial duration (week) | |||||
| ≤12 | 21 | 0.03 (−0.26, 0.33) | 0.831 | 0.510 | 0.0% |
| >12 | 23 | −2.64 (−4.39, −0.89) | 0.003 | <0.001 | 78.9% |
| Intervention dose (mg/day) | |||||
| <1000 | 30 | −1.80 (−2.88, −0.72) | 0.001 | <0.001 | 79.8% |
| ≥1000 | 14 | −0.83 (−2.07, 0.41) | 0.193 | 0.629 | 0.0% |
| Sex | |||||
| Female | 17 | −1.52 (−2.91, −0.13) | 0.031 | 0.006 | 52.7% |
| Both | 24 | −2.10 (−4.20, −0.01) | 0.049 | <0.001 | 78.3% |
| Male | 3 | 0.08 (−0.26, 0.44) | 0.630 | 0.670 | 0.0% |
| T2DM status | |||||
| Non-T2DM | 30 | −1.13 (−1.90, −0.37) | 0.004 | <0.001 | 63.8% |
| T2DM patients | 14 | −2.72 (−9.05, 3.60) | 0.399 | 0.002 | 59.9% |
| Baseline FBS (mg/dL) | |||||
| <100 | 19 | −1.22 (−2.09, −0.35) | 0.006 | <0.001 | 71.3% |
| ≥100 | 24 | −2.26 (−5.00, 0.47) | 0.106 | <0.001 | 69.2% |
| Subgroup analyses of green tea extract supplementation on fasting insulin (μlU/ml) | |||||
| Overall effect | 32 | −0.39 (−0.94, 0.16) | 0.165 | <0.001 | 68.2% |
| Baseline BMI (kg.m–2) | |||||
| Overweight (25-29.9) | 17 | −0.27 (−0.80, 0.24) | 0.300 | 0.038 | 41.5% |
| Obese (≥30) | 11 | −0.37 (−1.52, 0.77) | 0.521 | <0.001 | 80.5% |
| Trial duration (week) | |||||
| ≤12 | 14 | −0.45 (−1.09, 0.19) | 0.170 | 0.276 | 16.3% |
| >12 | 18 | −0.30 (−1.07, 0.47) | 0.447 | <0.001 | 79.2% |
| Intervention dose (mg/day) | |||||
| <1000 | 20 | −0.47 (−1.33, 0.38) | 0.278 | <0.001 | 77.4% |
| ≥1000 | 12 | −0.01 (−0.39, 0.36) | 0.947 | 0.632 | 0.0% |
| Sex | |||||
| Female | 13 | −0.78 (−1.71, 0.14) | 0.099 | <0.001 | 78.2% |
| Both | 17 | −0.04 (−0.74, 0.66) | 0.911 | 0.015 | 47.9% |
| Male | 2 | −0.04 (−0.96, 0.87) | 0.923 | 0.754 | 0.0% |
| T2DM status | |||||
| Non-T2DM | 19 | −0.54 (−1.22, 0.12) | 0.111 | <0.001 | 77.5% |
| T2DM patients | 13 | 0.08 (−0.78, 0.95) | 0.843 | 0.224 | 21.7% |
| Subgroup analyses of green tea extract supplementation on HbA1c (%) | |||||
| Overall effect | 17 | −0.15 (−0.26, −0.04) | 0.008 | <0.001 | 71.3% |
| Baseline BMI (kg.m–2) | |||||
| Normal weight (18.5-24.9) | 1 | −0.20 (−0.65, 0.25) | 0.391 | – | – |
| Overweight (25-29.9) | 7 | −0.26 (−0.58, 0.06) | 0.117 | 0.126 | 39.9% |
| Obese (≥30) | 5 | −0.06 (−0.09, −0.04) | <0.001 | 0.433 | 0.0% |
| Trial duration (week) | |||||
| ≤12 | 8 | −0.14 (−0.28, −0.00) | 0.049 | 0.109 | 40.5% |
| >12 | 9 | −0.13 (−0.32, 0.05) | 0.154 | 0.001 | 69.6% |
| Intervention dose (mg/day) | |||||
| <1000 | 13 | −0.10 (−0.22, 0.00) | 0.063 | <0.001 | 73.4% |
| ≥1000 | 4 | −0.51 (−0.82, −0.19) | 0.001 | 0.370 | 4.6% |
| Sex | |||||
| Female | 3 | −0.10 (−0.33, 0.13) | 0.394 | 1.000 | 0.0% |
| Both | 13 | −0.19 (−0.35, −0.02) | 0.021 | <0.001 | 68.5% |
| Male | 1 | −0.07 (−0.09, −0.04) | <0.001 | – | – |
| T2DM status | |||||
| Non-T2DM | 6 | −0.06 (−0.09, −0.04) | <0.001 | 0.962 | 0.0% |
| T2DM patients | 11 | −0.22 (−0.41, −0.03) | 0.019 | 0.001 | 68.0% |
| Baseline HbA1c (%) | |||||
| <6.5 | 8 | −0.07 (−0.09, −0.04) | <0.001 | 0.974 | 0.0% |
| ≥6.5 | 8 | −0.23 (−0.47, 0.01) | 0.061 | <0.001 | 77.4% |
| Subgroup analyses of green tea extract supplementation on HOMA-IR | |||||
| Overall effect | 21 | −0.18 (−0.42, 0.05) | 0.122 | <0.001 | 64.1% |
| Baseline BMI (kg.m–2) | |||||
| Overweight (25-29.9) | 12 | −0.14 (−0.43, 0.14) | 0.320 | 0.002 | |
| Obese (≥30) | 7 | −0.32 (−0.87, 0.22) | 0.249 | 62.5% | 76.7% |
| Trial duration (week) | |||||
| ≤12 | 10 | 0.08 (−0.16, 0.32) | 0.519 | 0.406 | 3.7% |
| >12 | 11 | −0.35 (−0.68, −0.01) | 0.040 | <0.001 | 77.8% |
| Intervention dose (mg/day) | |||||
| <1000 | 12 | −0.15 (−0.57, 0.26) | 0.472 | 0.001 | 64.0% |
| ≥1000 | 9 | −0.23 (−0.55, 0.09) | 0.161 | 0.002 | 68.1% |
| Sex | |||||
| Female | 9 | −0.01 (−0.12, 0.08) | 0.769 | 0.638 | 0.0% |
| Both | 11 | −0.33 (−1.04, 0.37) | 0.358 | <0.001 | 78.5% |
| T2DM status | |||||
| Male | 1 | 0.00 (−0.30, 0.30) | 1.000 | – | – |
| Non-T2DM | 11 | −0.29 (−0.59, 0.00) | 0.053 | <0.001 | 77.8% |
| T2DM patients | 10 | 0.11 (−0.22, 0.45) | 0.514 | 0.399 | 4.5% |
| Subgroup analyses of green tea extract supplementation on SBP (mmHg) | |||||
| Overall effect | 28 | −0.77 (−1.80, 0.26) | 0.144 | <0.001 | 92.3% |
| Baseline BMI (kg.m–2) | |||||
| Normal weight (18.5-24.9) | 6 | 0.73 (−1.82, 3.30) | 0.571 | 0.095 | 46.7% |
| Overweight (25-29.9) | 9 | −0.91 (−3.14, 1.30) | 0.417 | 0.001 | 68.6% |
| Obese (≥30) | 11 | −1.30 (−2.78, 0.17) | 0.083 | <0.001 | 96.4% |
| Trial duration (week) | |||||
| ≤12 | 14 | −1.28 (−2.61, 0.04) | 0.059 | <0.001 | 79.8% |
| >12 | 14 | −0.59 (−1.69, 0.50) | 0.287 | <0.001 | 67.8% |
| Intervention dose (mg/day) | |||||
| <1000 | 22 | −0.94 (−1.98, 0.09) | 0.075 | <0.001 | 90.2% |
| ≥1000 | 6 | 0.31 (−3.41, 4.04) | 0.868 | <0.001 | 86.4% |
| Sex | |||||
| Female | 7 | −0.70 (−3.18, 1.78) | 0.580 | <0.001 | 88.4% |
| Both | 17 | −0.42 (−1.86, 1.01) | 0.563 | <0.001 | 81.7% |
| Male | 4 | −2.02 (−3.40, −0.64) | 0.004 | 0.244 | 28.0% |
| T2DM status | |||||
| Non-T2DM | 20 | −1.38 (−2.45, −0.32) | 0.011 | <0.001 | 79.5% |
| T2DM patients | 8 | 0.36 (−1.13, 1.86) | 0.633 | 0.069 | 46.7% |
| Baseline SBP (mmHg) | |||||
| <130 | 12 | 0.12 (−1.17, 1.42) | 0.855 | 0.059 | 42.4% |
| ≥130 | 14 | −1.42 (−2.86, 0.00) | 0.051 | <0.001 | 95.8% |
| Subgroup analyses of green tea extract supplementation on DBP (mmHg) | |||||
| Overall effect | 28 | −0.87 (−1.45, −0.29) | 0.003 | <0.001 | 92.4% |
| Baseline BMI (kg.m–2) | |||||
| Normal weight (18.5-24.9) | 6 | −0.32 (−1.87, 1.22) | 0.680 | 0.759 | 0.0% |
| Overweight (25-29.9) | 8 | −0.49 (−2.41, 1.43) | 0.618 | <0.001 | 79.1% |
| Obese (≥30) | 12 | −0.88 (−1.61, −0.15) | 0.018 | <0.001 | 96.2% |
| Trial duration (week) | |||||
| ≤12 | 14 | −1.16 (−2.28, −0.04) | 0.042 | <0.001 | 95.2% |
| >12 | 14 | −0.45 (−1.28, 0.38) | 0.287 | <0.001 | 69.7% |
| Intervention dose (mg/day) | |||||
| <1,000 | 21 | −0.99 (−1.90, −0.09) | 0.031 | <0.001 | 93.8% |
| ≥1,000 | 6 | −0.02 (−1.68, 1.63) | 0.977 | 0.015 | 64.6% |
| Sex | |||||
| Female | 7 | −0.62 (−1.54, 0.29) | 0.183 | 0.095 | 44.4% |
| Both | 16 | −1.03 (−2.13, 0.07) | 0.067 | <0.001 | 83.9% |
| T2DM status | |||||
| Male | 5 | −0.40 (−2.25, 1.44) | 0.667 | <0.001 | 98.2% |
| Non-T2DM | 21 | −0.74 (−1.62, 0.12) | 0.094 | <0.001 | 92.9% |
| T2DM patients | 7 | −0.72 (−2.31, 0.85) | 0.368 | <0.001 | 80.1% |
| Baseline TG | |||||
| <80 | 12 | −0.28 (−0.97, 0.39) | 0.410 | 0.011 | 54.8% |
| ≥80 | 15 | −1.60 (−2.43, −0.78) | <0.001 | <0.001 | 66.7% |
| Subgroup analyses of green tea extract supplementation on CRP (mg/dL). | |||||
| Overall effect | 16 | −0.03 (−0.14, 0.08) | 0.619 | <0.001 | 90.2% |
| Baseline BMI (kg.m–2) | |||||
| Normal weight (18.5-24.9) | 1 | −1.09 (−3.27, 1.09) | 0.329 | – | – |
| Overweight (25-29.9) | 9 | 0.05 (−0.42, 0.54) | 0.816 | <0.001 | 93.5% |
| Obese (≥30) | 5 | 0.13 (−0.05, 0.33) | 0.155 | 0.002 | 75.9% |
| Trial duration (week) | |||||
| ≤12 | 11 | −0.00 (−0.05, 0.05) | 0.953 | 0.018 | 53.3% |
| >12 | 5 | −0.03 (−0.83, 0.75) | 0.928 | <0.001 | 96.8% |
| Intervention dose (mg/day) | |||||
| <1000 | 13 | 0.08 (−0.02, 0.18) | 0.113 | <0.001 | 68.8% |
| ≥1000 | 3 | −0.24 (−1.06, 0.58) | 0.565 | <0.001 | 98.2% |
| Sex | |||||
| Female | 4 | 0.00 (−0.07, 0.08) | 0.928 | 0.001 | 81.1% |
| Both | 10 | 0.05 (−0.49, 0.60) | 0.851 | <0.001 | 93.1% |
| Male | 2 | −0.24 (−0.89, 0.41) | 0.468 | 0.073 | 68.8% |
CI, confidence interval; WMD, weighted mean differences; BMI, body mass index; FBS, fasting blood sugar; HbA1c, hemoglobin A1C; HOMA-IR, homeostatic model assessment for insulin resistance; SBP, systolic blood pressure; DBP, diastolic blood pressure; TC, total cholesterol; TG, triglyceride; LDL-C, low-density cholesterol; HDL-C, high-density cholesterol; and CRP, C-reactive protein.