TABLE 2.

Subgroup analysis based on fixed-effects models for the effects of whole-grain consumption on inflammatory biomarkers in adults aged ≥18 y

	Effect size, n	Mean (95% CI)	P-within	I 2, %	P-between
Whole-grain consumption on serum concentrations of C-reactive protein
Overall	15	−0.29 (−1.10, 0.52)	0.48	97.0
Baseline concentrations					<0.001
Normal (<3 mg/L)	8	0.04 (−0.12, 0.20)	0.619	84.2
High (≥3 mg/L)	7	−1.10 (−1.30, −0.90)	<0.001	98.2
Health condition					0.006
Healthy	10	−0.35 (−0.48, −0.22)	<0.001	97.9
Unhealthy	5	−0.97 (−1.39, −0.55)	<0.001	77.2
Duration of intervention					<0.001
<8 wk	6	0.94 (0.67, 1.22)	<0.001	95.9
≥8 wk	9	−0.76 (−0.90, −0.62)	<0.001	96.5
Study design					<0.001
Parallel	10	−0.74 (−0.88, −0.60)	<0.001	96.0
Crossover	5	1.47 (1.15, 1.80)	<0.001	95.2
Calorie restriction					0.265
Hypocaloric diet	3	−0.22 (−0.57, 0.14)	0.232	53.3
Isocaloric diet	12	−0.43 (−0.57, −0.30)	<0.001	97.6
Type of intervention					0.48
Whole-grain–containing diet1	12	−0.33 (−1.36, 0.70)	0.524	97.6
Specif ic whole-grain product foods2	3	−0.29 (−1.10, 0.52)	0.083	0.0
Adjustment for baseline values					0.013
Nonadjusted	9	−0.10 (−0.37, 0.17)	0.462	91.2
Adjusted	6	−0.49 (−0.63, −0.35)	<0.001	97.6
Risk of bias					<0.001
Others	10	0.11 (−0.10, 0.31)	0.316	94.5
Low	5	−0.70 (−0.86, −0.54)	<0.001	98.5
Whole-grain consumption on serum concentrations of IL-6
Overall	11	−0.08 (−0.27, 0.11)	0.399	67.5
Baseline concentrations					0.84
Normal (<4.4 pg/mL)	10	−0.03 (−0.11, 0.05)	0.445	70.7
High (≥4.4 pg/mL)	1	0.50 (−4.67, 5.67)	0.850	0.0
Health condition					0.026
Healthy	7	−0.00 (−0.09, 0.08)	0.935	0.0
Unhealthy	4	−0.33 (−0.61, −0.06)	0.019	85.2
Duration of intervention					<0.001
<8 wk	4	−0.62 (−0.92, −0.32)	<0.001	59.2
≥8 wk	7	0.01 (−0.07, 0.10)	0.733	21.2
Study design					<0.001
Parallel	8	0.01 (−0.07, 0.10)	0.736	14.2
Crossover	3	−0.62 (−0.92, −0.32)	<0.001	67.5
Calorie restriction					0.413
Hypocaloric diet	3	0.07 (−0.19, 0.32)	0.594	0.0
Isocaloric diet	8	−0.04 (−0.13, 0.04)	0.326	75.4
Type of intervention					0.399
Whole-grain–containing diet	8	−0.14 (−0.37, 0.09)	0.243	75.9
Specific whole-grain product foods	3	0.10 (−0.16, 0.36)	0.465	67.5
Adjustment for baseline values					0.44
Nonadjusted	8	−0.05 (−0.17, 0.27)	0.659	0.0
Adjusted	3	−0.04 (−0.13, 0.04)	0.322	81.5
Risk of bias					0.355
Others	6	0.03 (−0.12, 0.18)	0.70	0.0
Low	5	−0.06 (−0.15, 0.04)	0.25	84.3
Whole-grain consumption on serum concentrations of TNF-α
Overall	7	−0.06 (−0.25, 0.14)	0.56	73.7
Baseline concentrations					0.67
Normal (<2.3 pg/mL)	5	−0.03 (−0.10, 0.04)	0.35	26.8
High (≥2.3 pg/mL)	2	−0.24 (−1.22, 0.74)	0.63	94.2
Health condition					0.26
Healthy	3	−0.00 (−0.09, 0.09)	0.96	88.5
Unhealthy	4	−0.08 (−0.19, 0.03)	0.14	27.8
Duration of intervention					0.853
<8 wk	3	−0.01 (−0.24, 0.21)	0.91	88.5
≥8 wk	4	−0.03 (−0.11, 0.04)	0.33	44.3
Study design					0.83
Parallel	5	−0.04 (−0.11, 0.04)	0.33	82.3
Crossover	2	−0.01 (−0.24, 0.21)	0.92	0.0
Calorie restriction					0.28
Hypocaloric diet	2	−0.09 (−0.22, 0.04)	0.15	56.3
Isocaloric diet	5	−0.01 (−0.09, 0.07)	0.82	79.4
Type of intervention					0.56
Whole-grain–containing diet	5	−0.05 (−0.14, 0.04)	0.25	13.8
Specific whole-grain product foods	2	−50.25 (−154.84, 54.33)	0.346	94.2
Adjustment for baseline values					0.176
Nonadjusted	6	−0.39 (−0.91, 0.13)	0.143	76.6
Adjusted	1	0.03 (−0.10, 0.04)	0.444	18.5
Risk of bias					0.78
Others	5	−0.04 (−0.11, 0.04)	0.32	27.2
Low	2	−0.00 (−0.23, 0.23)	0.98	94.2

¹Whole-grain–containing diet: contained a mix of different types of whole-grain foods.

²Specific types of whole-grain foods: limited to specific foods like brown rice, whole wheat, etc.