Dataset Information

Effect of low glycaemic index or load dietary patterns on glycaemic control and cardiometabolic risk factors in diabetes: systematic review and meta-analysis of randomised controlled trials.

ABSTRACT:

Objective

To inform the update of the European Association for the Study of Diabetes clinical practice guidelines for nutrition therapy.

Design

Systematic review and meta-analysis of randomised controlled trials.

Data sources

Medline, Embase, and the Cochrane Library searched up to 13 May 2021.

Eligibility criteria for selecting studies

Randomised controlled trials of three or more weeks investigating the effect of diets with low glycaemic index (GI)/glycaemic load (GL) in diabetes.

Outcome and measures

The primary outcome was glycated haemoglobin (HbA1c). Secondary outcomes included other markers of glycaemic control (fasting glucose, fasting insulin); blood lipids (low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), non-HDL-C, apo B, triglycerides); adiposity (body weight, BMI (body mass index), waist circumference), blood pressure (systolic blood pressure (SBP) and diastolic blood pressure (DBP)), and inflammation (C reactive protein (CRP)).

Data extraction and synthesis

Two independent reviewers extracted data and assessed risk of bias. Data were pooled by random effects models. GRADE (grading of recommendations assessment, development, and evaluation) was used to assess the certainty of evidence.

Results

29 trial comparisons were identified in 1617 participants with type 1 and 2 diabetes who were predominantly middle aged, overweight, or obese with moderately controlled type 2 diabetes treated by hyperglycaemia drugs or insulin. Low GI/GL dietary patterns reduced HbA1c in comparison with higher GI/GL control diets (mean difference −0.31% (95% confidence interval −0.42 to −0.19%), P<0.001; substantial heterogeneity, I2=75%, P<0.001). Reductions occurred also in fasting glucose, LDL-C, non-HDL-C, apo B, triglycerides, body weight, BMI, systolic blood pressure (dose-response), and CRP (P<0.05), but not blood insulin, HDL-C, waist circumference, or diastolic blood pressure. A positive dose-response gradient was seen for the difference in GL and HbA1c and for absolute dietary GI and SBP (P<0.05). The certainty of evidence was high for the reduction in HbA1c and moderate for most secondary outcomes, with downgrades due mainly to imprecision.

Conclusions

This synthesis suggests that low GI/GL dietary patterns result in small important improvements in established targets of glycaemic control, blood lipids, adiposity, blood pressure, and inflammation beyond concurrent treatment with hyperglycaemia drugs or insulin, predominantly in adults with moderately controlled type 1 and type 2 diabetes. The available evidence provides a good indication of the likely benefit in this population.

Study registration

ClinicalTrials.gov NCT04045938.

SUBMITTER: Chiavaroli L

PROVIDER: S-EPMC8336013 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Project description:Abstract Objectives Low-glycemic index (GI) and load (GL) dietary patterns are recommended for diabetes management by clinical practice guidelines globally. To inform the update of the European Association for the Study of Diabetes (EASD) clinical practice guidelines for nutrition therapy, we conducted a systematic review and meta-analysis on the effect of low-GI/GL dietary patterns on glycemic control and other established cardiometabolic risk factors in type 1 and 2 diabetes. Methods MEDLINE, EMBASE, and the Cochrane Library were searched through November 2020. We included randomized controlled trials ≥3-weeks investigating the effect of low-GI/GL diets in diabetes. The primary outcome was HbA1c. Two independent reviewers extracted data and assessed risk of bias. GRADE (grading of recommendations assessment, development, and evaluation) assessed the certainty of the evidence. (ClinicalTrials.gov identifier, NCT04045938) Results We identified 30 trial comparisons in 1,672 participants with type 1 and 2 diabetes who were predominantly middle-aged, overweight or obese with moderately controlled type 2 diabetes treated by antihyperglycemic agents and/or insulin. Low-GI/GL dietary patterns significantly reduced HbA1c compared with higher-GI/GL control diets (mean difference −0.32% [95% confidence interval −0.48, −0.16%], P < 0.001; substantial heterogeneity, I2 = 74%, P < 0.001). There were also significant reductions in several secondary outcomes: fasting glucose, LDL-C, non-HDL-C, body weight, BMI, and CRP (P < 0.05), but not insulin or blood pressure. The certainty of evidence was moderate for the reduction in HbA1c and most secondary outcomes. Conclusions Our synthesis indicates that low-GI/GL dietary patterns improve established targets of glycemic control, blood lipids, adiposity and inflammation beyond concurrent therapy with antihyperglycemic agents and/or insulin in moderately controlled type 1 and type 2 diabetes. The available evidence provides a good indication of the likely benefit in this population with moderate likelihood that more research will alter our conclusions. Funding Sources Diabetes and Nutrition Study Group of the EASD, CIHR.

Project description:OBJECTIVE:Carbohydrate staples such as pasta have been implicated in the obesity epidemic. It is unclear whether pasta contributes to weight gain or like other low-glycaemic index (GI) foods contributes to weight loss. We synthesised the evidence of the effect of pasta on measures of adiposity. DESIGN:Systematic review and meta-analysis using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. DATA SOURCES:MEDLINE, Embase, CINAHL and the Cochrane Library were searched through 7 February 2017. ELIGIBILITY CRITERIA FOR SELECTING STUDIES:We included randomised controlled trials??3?weeks assessing the effect of pasta alone or in the context of low-GI dietary patterns on measures of global (body weight, body mass index (BMI), body fat) and regional (waist circumference (WC), waist-to-hip ratio (WHR), sagittal abdominal diameter (SAD)) adiposity in adults. DATA EXTRACTION AND SYNTHESIS:Two independent reviewers extracted data and assessed risk of bias. Data were pooled using the generic inverse-variance method and expressed as mean differences (MDs) with 95% CIs. Heterogeneity was assessed (Cochran Q statistic) and quantified (I2 statistic). GRADE assessed the certainty of the evidence. RESULTS:We identified no trial comparisons of the effect of pasta alone and 32 trial comparisons (n=2448 participants) of the effect of pasta in the context of low-GI dietary patterns. Pasta in the context of low-GI dietary patterns significantly reduced body weight (MD=-0.63?kg; 95% CI -0.84 to -0.42?kg) and BMI (MD=-0.26?kg/m2; 95% CI -0.36 to -0.16?kg/m2) compared with higher-GI dietary patterns. There was no effect on other measures of adiposity. The certainty of the evidence was graded as moderate for body weight, BMI, WHR and SAD and low for WC and body fat. CONCLUSIONS:Pasta in the context of low-GI dietary patterns does not adversely affect adiposity and even reduces body weight and BMI compared with higher-GI dietary patterns. Future trials should assess the effect of pasta in the context of other 'healthy' dietary patterns. TRIAL REGISTRATION NUMBER:NCT02961088; Results.