Table 2.

Subgroup analysis on the effects of GCE supplementation on glycemic and lipid measures

	Effect size, n	WMD1	95% CI1	P-value2	Heterogeneity
					I2 (%)3	P-heterogeneity4
The effect of GCE on FBS
Overall effect size	12	-2.35	−3.78, −0.92	0.001	45.8	0.037
Participants’ gender
Male	2	−1.32	−3.87, 1.22	0.31	0.0	0.92
Female	4	−1.13	−2.47, 0.21	0.098	57.5	0.07
Both genders	6	−3.55	−5.10, −2.01	< 0.001	36.3	0.17
Intervention duration (week)
≥ 8	11	−2.13	−3.12, −1.13	< 0.001	51.1	0.025
< 8	1	−1.40	−4.35, 1.55	0.35	–	–
Baseline FBS
Elevated (≥100 mg/dL)	3	−5.28	−7.93, −2.63	< 0.001	44.10	0.17
Normal (< 100 mg/dL)	9	−1.59	−2.59, −0.58	0.002	24.20	0.23
Compliance
Acceptable	5	−3.59	−5.15, −2.04	< 0.001	47.6	0.11
Unacceptable/Unclear	7	−1.16	−2.34, 0.02	0.053	15.5	0.31
The effect of GCE on insulin levels
Overall effect size	7	−0.63	−1.11, − 0.15	0.01	49.4	0.07
Participants’ gender
Female	3	−0.31	−0.52, − 0.10	0.004	54.4	0.11
Both genders	4	−0.77	−1.21, − 0.33	0.001	26.0	0.26
Compliance
Acceptable	4	−0.77	−1.21, − 0.33	0.001	26.0	0.26
Unacceptable/Unclear	3	−0.31	−0.52, − 0.10	0.004	54.4	0.11
The effect of GCE on TG levels
Overall effect size	15	−3.17	−11.82, 5.49	0.47	59.1	0.002
Participants’ gender
Male	5	−1.05	−11.70, 9.60	0.85	0.0	0.99
Female	4	2.76	−5.18, 10.70	0.49	79.6	0.002
Both genders	6	−7.83	−15.22, −0.44	0.04	68.0	0.008
Intervention duration (week)
≥ 8	11	−2.87	−8.27, 2.53	0.29	70.6	< 0.001
< 8	4	−1.21	−11.91, 9.50	0.83	0.0	0.99
Baseline TG
Elevated (≥150 mg/dL)	4	−4.58	−12.77, 3.60	0.27	74.9	0.008
Normal (< 150 mg/dL)	11	−1.44	−7.41, 4.53	0.64	54.4	0.02
Compliance
Acceptable	8	−6.14	−12.44, 0.17	0.06	57.3	0.02
Unacceptable/Unclear	7	2.55	−4.93, 10.03	0.50	59.5	0.02
The effect of GCE on TC levels
Overall effect size	16	−4.51	−8.39, −0.64	0.02	44.1	0.03
Participants’ gender
Male	5	−1.51	−6.78, 3.75	0.57	5.6	0.38
Female	5	−5.29	−8.87, −1.71	0.004	44.2	0.13
Both genders	6	−7.48	−12.11, −2.86	0.002	60.4	0.03
Intervention duration (week)
≥ 8	12	−6.11	−8.91, −3.30	< 0.001	45.9	0.04
< 8	4	−1.22	−6.65, 4.22	0.66	26.0	0.26
Baseline TC
Elevated (≥200 mg/dL)	8	−6.06	−9.01, − 3.12	< 0.001	26.2	0.22
Normal (< 200 mg/dL)	8	−2.60	−7.28, 2.09	0.28	55.8	0.03
Compliance
Acceptable	8	−4.88	−8.53, −1.23	0.009	59.4	0.02
Unacceptable/Unclear	8	−5.26	−8.66, −1.85	0.003	27.0	0.21
The effect of GCE on LDL levels
Overall effect size	15	−2.02	−5.58, 1.54	0.27	47.6	0.02
Participants’ gender
Male	5	0.58	−4.59, 5.76	0.83	3.4	0.39
Female	4	−6.96	−10.01, −3.90	< 0.001	61.1	0.05
Both genders	6	−1.44	−5.45, 2.57	0.48	25.5	0.24
Intervention duration (week)
≥ 8	11	−5.01	−7.42, −2.61	< 0.001	47.9	0.04
< 8	4	1.70	−3.79, 7.19	0.54	0.0	0.44
Baseline LDL
Elevated (≥130 mg/dL)	2	0.10	−5.73, 5.53	0.97	28.9	0.24
Normal (< 130 mg/dL)	13	−4.63	−7.02, −2.24	< 0.001	48.3	0.03
Compliance
Acceptable	8	0.01	−3.38, 3.41	0.99	11.1	0.34
Unacceptable/Unclear	7	−6.79	−9.68, −3.90	< 0.001	39.4	0.13
The effect of GCE on HDL levels
Overall effect size	15	1.08	−0.22, 2.38	0.10	37.6	0.07
Participants’ gender
Male	5	0.06	−2.16, 2.27	0.96	0.0	0.99
Female	4	2.92	2.46, 3.39	< 0.001	62.0	0.05
Both genders	6	0.63	−1.37, 2.62	0.54	0.0	0.59
Intervention duration (week)
≥ 8	11	2.79	2.34, 3.24	< 0.001	43.0	0.06
< 8	4	0.18	−2.12, 2.49	0.88	0.0	0.99
Baseline HDL
Low (< 40 mg/dL)	5	2.87	2.41, 3.33	< 0.001	56.4	0.06
Normal (≥40 mg/dL)	10	0.34	−1.36, 2.04	0.69	0.0	0.81
Compliance
Acceptable	8	0.51	−1.06, 2.09	0.52	0.0	0.91
Unacceptable/Unclear	7	2.88	2.42, 3.14	< 0.001	48.7	0.07

¹Obtained from the fixed-effects model

²Refers to the mean (95% CI)

³Inconsistency, percentage of variation across studies due to heterogeneity

⁴Obtained from the Q-test

Abbreviations: GCE green coffee extract, WMD weighted mean difference, CI confidence interval, TG triglycerides, TC total cholesterol, LDL low-density lipoprotein, HDL high-density lipoprotein, FBG fasting blood glucose