Dietary Fiber Intake and Type 2 Diabetes Mellitus: An Umbrella Review of Meta-analyses

Table 2

Effects of Increased Fiber Intake on Changes in Fasting Blood Glucose Concentrations

Meta-analysis Authors and Date	No. of Studies in Meta-analysis	No. of Participants in Meta-analysis	Fiber Type and Dose/Day	Mean Duration in Weeks	Reduction in Fasting Blood Glucose Concentration in mg/dL	Q Test P Value and I² Statistic	Egger or Begg Test P Value	Quality Assessment and Outcome
Post et al, 2012²³^a	13 T2D	400	Soluble 18 g	8	↓ 15.3, P < .001	NS, 5%		GRADE 9/13 high quality

Silva et al, 2013²⁴	8 T2D	496	Soluble 11 g	12	↓ 10.0, P < .05	P < .001, 96%	NS	GRADE NR

Tiwari and Cummins, 2011²⁵	22	487	β-Glucan 6 g	6	↓ 44.6, P < .001	P < .001, 97%	NS

Bao et al, 2014²⁶	12	630	β-Glucan 5.5 g	8	↓ 0.7, NS	P < .001, 68%	NS	Jadad scale 7/12 high quality

Zhu et al, 2015²⁷	8	378	β-Glucan 5 g	6.5	↓ 0.4, NS	NS, 0%	NS	Jadad scale 4/8 high quality

Zou et al, 2015²⁸	12	603	β-Glucan 5 g	6	↓ 0.9, NS	NS, 0%	NS	Jadad scale 7/12 high quality

Hou et al, 2015²⁹	6 T2D	437	β-Glucan NR	4.5	↓ 7.0, P < .001	NS, 0%		NOS 5/6 high quality

Shen et al, 2016³⁰	4 T2D	239	β-Glucan 3g	4.5	↓ 9.4, P < .01	NS, 0%	NS	Cochrane 3/4 high quality

He et al, 2016³¹	16	933	β-Glucan 5.5g	7.5	↓ 2.3, P < .01	P < .001, 99%

Gibb et al, 2015³²	4 T2D 14	245 1267	Psyllium 12g Psyllium 10 g	8.5 9.5	↓ 37.0, P < .05 ↓ 1.6, NS	P < .05, 61% P < .05, 68%

Liu et al, 2016³³	15	579	Fructans 12.5 g	7.5	↓ 0.9, NS	NS, 26%	P < .05	Cochrane 4/15 high quality

NOS, Newcastle-Ottawa Scale;
NR, not reported;
NS, not significant;
T2D, participants with type 2 diabetes only.

^aLow-quality score on the Critical Appraisal Checklist for Systematic Reviews.