scholarly journals Effect of folate supplementation on insulin sensitivity and type 2 diabetes: a meta-analysis of randomized controlled trials

2019 ◽  
Vol 109 (1) ◽  
pp. 29-42 ◽  
Author(s):  
Mads Vendelbo Lind ◽  
Lotte Lauritzen ◽  
Mette Kristensen ◽  
Alastair B Ross ◽  
Jane Nygaard Eriksen
Keyword(s):  
Insulin Resistance ◽  
Type 2 Diabetes ◽  
Randomized Controlled Trials ◽  
Fasting Glucose ◽  
Meta Analysis ◽  
Controlled Trials ◽  
Folate Supplementation ◽  
Randomized Controlled ◽  
Meta Analyses

ABSTRACT Background Various mechanisms link higher total homocysteine to higher insulin resistance (IR) and risk of type 2 diabetes (T2D). Folate supplementation is recognized as a way to lower homocysteine. However, randomized controlled trials (RCTs) show inconsistent results on IR and T2D outcomes. Objective The aim of this study was to examine the effect of folate supplementation on IR and T2D outcomes. Design We conducted a systematic literature search in PubMed, Web of Science, and EMBASE and prior systematic reviews and meta-analyses and identified 29 RCTs (22,250 participants) that assessed the effect of placebo-controlled folate supplementation alone or in combination with other B vitamins on fasting glucose, insulin, homeostasis model assessment for insulin resistance (HOMA-IR), glycated hemoglobin (HbA1c), or risk of T2D. The meta-analysis was conducted using both random- and fixed-effects models to calculate weighted mean differences (WMDs) or risk ratios with 95% CIs. Subgroup analyses were conducted based on intervention type (folate alone or in combination with other B vitamins), as well as analysis based on population characteristics, duration, dose, and change in homocysteine. Results When compared with placebo, folate supplementation lowered fasting insulin (WMD: −13.47 pmol/L; 95% CI: −21.41, −5.53 pmol/L; P < 0.001) and HOMA-IR (WMD: −0.57 units; 95% CI: −0.76, −0.37 units; P < 0.0001), but no overall effects were observed for fasting glucose or HbA1c. Heterogeneity was low in all meta-analyses, and subgroup analysis showed no signs of effect modification except for change in homocysteine, with the most pronounced effects in trials with a change of >2.5 µmol/L. Changes in homocysteine after folate supplementation correlated with changes in fasting glucose (β = 0.07; 95% CI: 0.01, 0.14; P = 0.025) and HbA1c (β = 0.46; 95% CI: 0.06, 0.85; P = 0.02). Only 2 studies examined folate supplementation on risk of T2D, and they found no change in RR (pooled RR: 0.91; 95% CI: 0.80, 1.04; P = 0.16). Conclusion Folate supplementation might be beneficial for glucose homeostasis and lowering IR, but at present there are insufficient data to conclusively determine the effect on development of T2D. This trial was registered on the Prospero database as CRD42016048254.

scholarly journals Acute glycemic and insulinemic effects of low-energy sweeteners: a systematic review and meta-analysis of randomized controlled trials

2020 ◽  
Vol 112 (4) ◽  
pp. 1002-1014 ◽  
Author(s):  
Arno Greyling ◽  
Katherine M Appleton ◽  
Anne Raben ◽  
David J Mela
Keyword(s):  
Systematic Review ◽  
Type 2 Diabetes ◽  
Randomized Controlled Trials ◽  
Fasting Glucose ◽  
Meta Analysis ◽  
Low Energy ◽  
Controlled Trials ◽  
Randomized Controlled ◽  
The Mean

ABSTRACT Background It has been suggested that low-energy sweeteners (LES) may be associated with an increased risk of metabolic diseases, possibly due to stimulation of glucose-responsive mechanisms. Objective We conducted a systematic review and meta-analysis of human intervention studies examining the acute effect of LES intake on postprandial glucose (PPG) and postprandial insulin (PPI) responses, in order to comprehensively and objectively quantify these relations. Methods We systematically searched the Medline, OVID FSTA, and SCOPUS databases until January 2020. Randomized controlled trials comparing acute postprandial effects on PPG and/or PPI after exposure to LES, either alone, with a meal, or with other nutrient-containing preloads to the same intervention without LES were eligible for inclusion. PPG and PPI responses were calculated as mean incremental area under the curve divided by time. Meta-analyses were performed using random effects models with inverse variance weighing. Results Twenty-six papers (34 PPG trials and 29 PPI trials) were included. There were no reports of statistically significant differences in the effects of LES on PPG and PPI responses compared with control interventions. Pooled effects of LES intake on the mean change difference in PPG and PPI were −0.02 mmol/L (95% CI: −0.09, 0.05) and −2.39 pmol/L (95% CI: −11.83, 7.05), respectively. The results did not appreciably differ by the type or dose of LES consumed, cointervention type, or fasting glucose and insulin levels. Among patients with type 2 diabetes, the mean change difference indicated a smaller PPG response after exposure to LES compared with the control (−0.3 mmol/L; 95% CI: −0.53, −0.07). Conclusions Ingestion of LES, administered alone or in combination with a nutrient-containing preload, has no acute effects on the mean change in postprandial glycemic or insulinemic responses compared with a control intervention. Apart from a small beneficial effect on PPG (−0.3 mmol/L) in studies enrolling patients with type 2 diabetes, the effects did not differ by type or dose of LES, or fasting glucose or insulin levels. This review and meta-analysis was registered at PROSPERO as CRD42018099608.

scholarly journals The Effect of Probiotic Yogurt on Glycemic Control in Type 2 Diabetes or Obesity: A Meta-Analysis of Nine Randomized Controlled Trials

Nutrients ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 671 ◽  
Author(s):  
Elena Barengolts ◽  
Emily Smith ◽  
Sirimon Reutrakul ◽  
Livia Tonucci ◽  
Thunyarat Anothaisintawee
Keyword(s):  
Insulin Resistance ◽  
Type 2 Diabetes ◽  
Randomized Controlled Trials ◽  
Meta Analysis ◽  
Controlled Trials ◽  
Randomized Controlled ◽  
Probiotic Yogurt ◽  
Patients With Diabetes ◽  
Glycemic Markers

Probiotic yogurt is suggested as a nutritional approach in type 2 diabetes (T2D) and obesity. We performed a systematic review and meta-analysis of randomized controlled trials (RCTs) evaluating the effects of probiotic yogurt on glycemic outcomes in T2D or obesity. The databases used to search for RCTs included Medline and Scopus. The RCTs were eligible if outcomes included selected glycemic markers. In nine eligible trials, 237 and 235 subjects were in treatment (probiotic yogurt) and control (mostly conventional yogurt) groups, respectively. There was no significant difference for pooled unstandardized mean difference (USMD) hemoglobin A1c (HbA1c) by probiotic yogurt compared with the control in T2D (USMD: −0.366; 95% CI: −0.755, 0.024, p = 0.066) and obesity (USMD: 0.116, 95% CI: −0.007, 0.238, p = 0.065). Similarly, there were no effects of probiotic yogurt on fasting blood glucose, fasting insulin, or insulin resistance (estimated by homeostatic model assessment of insulin resistance (HOMA-IR)) in either T2D or obesity. In conclusion, the present meta-analysis has not demonstrated the benefits of consuming probiotic compared with conventional yogurt for improving glucose control in patients with diabetes or obesity. Larger trials are needed to verify the benefits of probiotic and/or conventional yogurt or other probiotic fermented milk (e.g., kefir) on glycemic markers in patients with diabetes and obesity.

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