Poor Quality of Dietary Assessment in Randomised Controlled Trials of Nutritional Interventions for Type 2 Diabetes May Impact Outcome Conclusions: A Systematic Review

Abstract Objectives Diet is critical in diabetes management and new nutritional interventions are continuously being tested in randomized controlled trials. However, to make meaningful conclusions about the efficacy of dietary treatments, it is critical to be certain that the participants adhered to the dietary intervention and the dietary changes are valid. The objective of this meta-analysis was to assess the quality of dietary assessment and whether it might impact on study metabolic outcomes. Methods Four databases, MEDLINE, EMBASE, CINAHL and CENTRAL, were searched, from inception until September 2019 for randomized controlled trials of nutritional interventions in people with non-insulin-dependent type 2 diabetes. Trials that measured nutritional intakes in methods and HbA1c as an outcome were included. Investigators assessed risk of bias and quality of the dietary measurements using the Cochrane Risk of Bias Assessment Tool 2.0 and a redeveloped EURICA tool, respectively. The study was conducted in accordance with the Preferred Reporting in Systematic Reviews and Meta-analyses. PROSPERO registration number: CRD42019146471. Results Of 2552 records retrieved, 23 studies met the inclusion criteria. Nineteen studies aimed to achieve a reduction in HbA1c, and four studies aimed to maintain HbA1c while improving other metabolic/nutritional outcomes. Two studies were rated as ‘good’, six as ‘medium’, and 15 as ‘poor’ in the quality assessment of the dietary measurement tool. The majority of studies were rated as high risk of bias. Of those studies with medium or high diet quality assessment, six of eight achieved the desired outcome whereas only four of the 15 other studies achieved the desired clinical outcome for HbA1c. Conclusions The poor quality of dietary assessment in clinical trials manipulating dietary intakes casts uncertainty on the legitimacy of causal mechanisms attributed to dietary interventions. Attention to the validity and reliability of dietary assessment methods is warranted. Funding Sources No funding support for conducting this review was received.

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Effect of Oats and Oat-Fiber on Glycemic Control in Diabetes: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Current Developments in Nutrition ◽

10.1093/cdn/nzab041_004 ◽

2021 ◽

Vol 5 (Supplement_2) ◽

pp. 489-489

Author(s):

Victoria Chen ◽

Andreea Zurbau ◽

Amna Ahmed ◽

Tauseef Khan ◽

Cyril Kendall ◽

...

Keyword(s):

Systematic Review ◽

Type 2 Diabetes ◽

Glycemic Control ◽

Randomized Controlled Trials ◽

Plasma Glucose ◽

Meta Analysis ◽

Risk Of Bias ◽

Controlled Trials ◽

Randomized Controlled

Abstract Objectives Current approved health claims in Canada, US and Europe recognize the ability of oat ß-glucan to lower blood cholesterol; however, its ability to improve glycemic control is less certain. We undertook a systematic review and meta-analysis of randomized controlled trials to update the evidence of the effect of oats and oat-fiber on markers of glycemic control in people with and without diabetes. Here we present data for the subgroup with diabetes. Methods MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials were searched through September 23rd, 2020. We included randomized controlled trials of ≥ 2-weeks of sources of oat ß-glucan and measures of glycemic control in diabetes. Two independent reviewers extracted relevant data and assessed the risk of bias (Cochrane Risk of Bias 2.0 Tool). The outcomes were fasting plasma glucose (FPG), 2h-plasma glucose (2h-PG) from a 75 g-oral glucose tolerance test, HbA1c and fasting plasma insulin (FPI). Data were pooled using the generic inverse variance method. Heterogeneity was assessed (Cochran Q statistic) and quantified (I2 statistic). Pooled estimates were expressed as mean differences with 95% confidence intervals (CI). GRADE assessed the certainty of the evidence. Results Eligibility criteria were met by 5 trial comparisons (N = 359) in type 2 diabetes. No trials were identified in type 1 diabetes. Consumption of oat ß-glucan sources reduced FPG (MD = −0.37 mmol/L [95% CI: −0.70, −0.05 mmol/L], P = 0.03, I2 = 0.00%, PQ = 0.76) and 2h-PG (MD = −1.24 mmol/L [95% CI: −1.97, −0.51 mmol/L], P = 0.00, I2 = 0.00%, PQ = 0.56). There were non-significant reductions in HbA1c (MD = −0.12%, [95% CI: −0.26, 0.01%], P = 0.07, I2 = 0.00%, PQ = 1.00) and FPI (MD = −4.59 pmol/L, [95% CI: −14.71, 5.52 pmol/L], P = 0.37, I2 = 40.84%, PQ = 0.19). The certainty of evidence was high for 2h-PG and moderate for FPG, HbA1c and FPI (single downgrades for imprecision in each case). Conclusions Current evidence provides a good indication that consumption of oat ß-glucan results in small improvements of glycemic control in type 2 diabetes. More high quality randomized trials are required to improve the precision of the pooled estimates. (ClinicalTrials.gov identifier, NCT04631913) Funding Sources Quaker Oats Center of Excellence, Diabetes Canada, Banting & Best Diabetes Centre, Toronto 3D foundation

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Poor quality of dietary assessment in randomised controlled trials of nutritional interventions for type 2 diabetes may impact outcome conclusions: a systematic review and meta-analysis

Nutrition ◽

10.1016/j.nut.2021.111498 ◽

2021 ◽

pp. 111498

Author(s):

Tian Wang ◽

George Siopis ◽

Hiu Yee Wong ◽

Margaret Allman-Farinelli

Keyword(s):

Randomised Controlled Trials ◽

Meta Analysis ◽

Dietary Assessment ◽

Poor Quality ◽

Controlled Trials ◽

Nutritional Interventions ◽

Randomised Controlled ◽

Impact Outcome

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Sodium glucose co-transporter 2 inhibitors for glycemic control in type 2 diabetes mellitus: Quality of reporting of randomized controlled trials

Perspectives in Clinical Research ◽

10.4103/2229-3485.173777 ◽

2016 ◽

Vol 7 (1) ◽

pp. 21 ◽

Cited By ~ 3

Author(s):

Rakesh Mittal ◽

Niti Mittal ◽

Harish Kumar ◽

Bikash Medhi

Keyword(s):

Diabetes Mellitus ◽

Type 2 Diabetes ◽

Type 2 Diabetes Mellitus ◽

Glycemic Control ◽

Randomized Controlled Trials ◽

Controlled Trials ◽

Quality Of Reporting ◽

Randomized Controlled

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Effectiveness of Internet-Based Interventions on Glycemic Control in Patients With Type 2 Diabetes: Meta-Analysis of Randomized Controlled Trials (Preprint)

10.2196/preprints.9133 ◽

2017 ◽

Author(s):

Ying Shen ◽

Fengbin Wang ◽

Xing Zhang ◽

Xiaorou Zhu ◽

Qiudan Sun ◽

...

Keyword(s):

Diabetes Mellitus ◽

Type 2 Diabetes ◽

Type 2 Diabetes Mellitus ◽

Glycemic Control ◽

Randomized Controlled Trials ◽

Meta Analysis ◽

Risk Of Bias ◽

Controlled Trials ◽

Randomized Controlled

BACKGROUND The popularity of internet as an area of research has grown manifold over the years. Given its rapid development and increasing coverage worldwide, internet-based interventions seem to offer a promising option to ameliorate huge burdens brought by type 2 diabetes mellitus. However, studies conducted by different researchers have provided contradictory results on the effect of internet-based interventions in glycemic control. OBJECTIVE This meta-analysis aims to summarize currently available evidence and evaluate the overall impact of internet-based interventions on glycemic management of type 2 diabetic patients. METHODS A systematic literature search was performed in PubMed, ScienceDirect, and Web of Science. Randomized controlled trials that used glycosylated hemoglobin values as the outcome measure of glycemic control were considered. Risk of bias and publication bias were evaluated. RESULTS Of the 492 studies, 35 were included in meta-analysis, and results indicated that the weighted mean difference (WMD) between usual care and internet-based interventions at endpoint was –0.426% (95% CI –0.540 to –0.312; P<.001). Subgroup analyses revealed that intervention duration ≤3 months yielded optimal performance (WMD –0.51%; 95% CI –0.71 to –0.31; P<.001). Combined mobile and website interventions were substantially superior to solely Web-based and mobile-based interventions in glycemic control (combined WMD –0.77%, 95% CI –1.07 to –0.47; P<.001; Web only: WMD –0.48%; 95% CI –0.71 to –0.24, P<.001; mobile only WMD –0.31%, 95% CI –0.49 to –0.14; P<.001). Furthermore, the effect of interventions with automated feedbacks was similar to those with manual feedbacks, and studies with internet-based educational contents were more effective in glycemic control. The assessment revealed a low risk of bias. CONCLUSIONS In conclusion, utilization of internet-based intervention is beneficial for patients with type 2 diabetes mellitus, and taking full advantage of this type of intervention may substantially reduce the incidence of complications and improve quality of life. CLINICALTRIAL International Prospective Register of Systematic Reviews (PROSPERO): CRD42017058032; https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=58032 (Archived by WebCite at http://www.webcitation.org/6yY7eQNHr)

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