Effects comparison between low glycemic index diets and high glycemic index diets on HbA1c and fructosamine for patients with diabetes: A systematic review and meta-analysis

Aims: The purpose of this study is to evaluate the effect of low glycemic index (GI) through the comparison of low-GI foods group and high-GI foods group on glycemic control (the measurements were HbA1c and fructosamine) for patients with diabetes. Methods: The studies were retrieved from databases including PubMed, MEDLINE, Springer, Elsevier Science Direct, Cochrane Library and Google scholar from their inception to August 2014. Review Manager 5.1 and STATA package v.11.0 software were applied for the metaanalysis. Standard mean difference (5WD) and its corresponding 95% confidence interval (CI) for HbA1c and fructosamine of patients with diabetes were collected and calculated in a fixed or random effects model when appropriate. Subgroup analysis stratified by study design, geographic area of participants and types of diabetes were also conducted. Results: There were significant differences of overall effects on HbA1c between low-GI foods group and high-GI foods group (SWD = -0.42, 95%CI -0.69 to -0.16, P<0.01) in patients with diabetes, and the subgroup analysis indicated that significant differences of HbA1c were also found between the two groups in crossover study, in Australian population and American population, as well as in type 2 diabetes. The overall fructosamine was also significantly different in patients with diabetes between low-GI foods and high-GI foods group (SMD = -0.44, 95%CI = -0.82 to -0.06, P = 0.02). Conclusions: Our results suggest that low-GI diets achieve a more beneficial effect on glycemic control than that of high-GI foods diets. (C) 2014 Primary Care Diabetes Europe. Published by Elsevier Ltd. All rights reserved.