Folic Acid Supplementation Improves Glycemic Control for Diabetes Prevention and Management: A Systematic Review and Dose-Response Meta-Analysis of Randomized Controlled Trials

Non-causal relationship of polycystic ovarian syndrome with homocysteine and B vitamins: evidence from a two-sample Mendelian randomization

Objective

Previous observational studies have identified a correlation between elevated plasma homocysteine (Hcy) levels and polycystic ovary syndrome (PCOS). This study aimed to determine whether a causal relationship exists between Hcy and PCOS at the genetic level.

Methods

A two-sample Mendelian Randomization (TSMR) study was implemented to assess the genetic impact of plasma levels of Hcy, folate, vitamin B12, and vitamin B6 on PCOS in individuals of European ancestry. Independent single nucleotide polymorphisms (SNPs) associated with Hcy (n=12), folate (n=2), vitamin B12 (n=10), and vitamin B6 (n=1) at genome-wide significance levels (P<5×10-8) were selected as instrumental variables (IVs). Data concerning PCOS were obtained from the Apollo database. The primary method of causal estimation was inverse variance weighting (IVW), complemented by sensitivity analyses to validate the results.

Results

The study found no genetic evidence to suggest a causal association between plasma levels of Hcy, folate, vitamin B12, vitamin B6, and PCOS. The effect sizes, determined through random-effect IVW, were as follows: Hcy per standard deviation increase, OR = 1.117, 95%CI: (0.842, 1.483), P = 0.442; folate per standard deviation increase, OR = 1.008, CI: (0.546, 1.860), P = 0.981; vitamin B12 per standard deviation increase, OR = 0.978, CI: (0.808, 1.185), P = 0.823; and vitamin B6 per standard deviation increase, OR = 0.967, CI: (0.925, 1.012), P = 0.145. The fixed-effect IVW results for each nutrient exposure and PCOS were consistent with the random-effect IVW findings, with additional sensitivity analyses reinforcing these outcomes.

Conclusion

Our findings indicate no causal link between Hcy, folate, vitamin B12, vitamin B6 levels, and PCOS.

Folic acid supplementation on inflammation and homocysteine in type 2 diabetes mellitus: systematic review and meta-analysis of randomized controlled trials

BACKGROUND

The beneficial effects of folate have been observed under different conditions, but the available evidence on inflammation and reduction of cardiovascular disease (CVD) in type 2 diabetes mellitus (T2DM) is limited. The study aimed to explore the effects of folate on inflammation and homocysteine amongst individuals with T2DM.

METHODS

PubMed, Scopus, and Cochrane Library were used to search for evidence. A random-effect model meta-analysis through Review Manager (version 5.4) and metaHun was performed. Results were reported as standardized mean differences (SMD) and 95% confidence intervals graphically using forest and funnel plots.

RESULTS

Data from 9 trials with 426 patients living with T2DM were analyzed. Folic acid supplementation significantly revealed a large effect size on homocysteine levels compared to placebo, SMD = -1.53, 95%CI (-2.14,-0.93), p < 0.05. Additionally, we observed a medium marginal effect size on C-reactive protein (SMD = -0.68, 95%CI (-1.34, -0.01), p = 0.05). However, no significant effect on tumor necrosis factor-α (SMD = -0.86, 95%CI (-2.65, 0.93), p = 0.34), and interleukin-6 (SMD = -0.04, 95%CI (-1.08, 1.01), p = 0.95) was observed.

CONCLUSION

Evidence analyzed in this study suggests that folic acid supplementation in T2DM reduces homocysteine and may mitigate CVDs. However, its effect on inflammation is inconclusive.

Immunomodulation through Nutrition Should Be a Key Trend in Type 2 Diabetes Treatment

An organism's ability to function properly depends not solely on its diet but also on the intake of nutrients and non-nutritive bioactive compounds that exert immunomodulatory effects. This principle applies both to healthy individuals and, in particular, to those with concomitant chronic conditions, such as type 2 diabetes. However, the current food industry and the widespread use of highly processed foods often lead to nutritional deficiencies. Numerous studies have confirmed the occurrence of immune system dysfunction in patients with type 2 diabetes. This article elucidates the impact of specific nutrients on the immune system function, which maintains homeostasis of the organism, with a particular emphasis on type 2 diabetes. The role of macronutrients, micronutrients, vitamins, and selected substances, such as omega-3 fatty acids, coenzyme Q10, and alpha-lipoic acid, was taken into consideration, which outlined the minimum range of tests that ought to be performed on patients in order to either directly or indirectly determine the severity of malnutrition in this group of patients.

Effects of supplementation with milk protein on glycemic parameters: a GRADE-assessed systematic review and dose-response meta-analysis

BACKGROUND

It is suggested that supplementation with milk protein (MP) has the potential to ameliorate the glycemic profile; however, the exact impact and certainty of the findings have yet to be evaluated. This systematic review and dose-response meta-analysis of randomized controlled trials (RCTs) assessed the impact of MP supplementation on the glycemic parameters in adults.

METHODS

A systematic search was carried out among online databases to determine eligible RCTs published up to November 2022. A random-effects model was performed for the meta-analysis.

RESULTS

A total of 36 RCTs with 1851 participants were included in the pooled analysis. It was displayed that supplementation with MP effectively reduced levels of fasting blood glucose (FBG) (weighted mean difference (WMD): -1.83 mg/dL, 95% CI: -3.28, -0.38; P = 0.013), fasting insulin (WMD: -1.06 uU/mL, 95% CI: -1.76, -0.36; P = 0.003), and homeostasis model assessment of insulin resistance (HOMA-IR) (WMD: -0.27, 95% CI: -0.40, -0.14; P < 0.001) while making no remarkable changes in serum hemoglobin A1c (HbA1c) values (WMD: 0.01%, 95% CI: -0.14, 0.16; P = 0.891). However, there was a significant decline in serum levels of HbA1c among participants with normal baseline body mass index (BMI) based on sub-group analyses. In addition, HOMA-IR values were significantly lower in the MP supplement-treated group than their untreated counterparts in short- and long-term supplementation (≤ 8 and > 8 weeks) with high or moderate doses (≥ 60 or 30-60 g/d) of MP or whey protein (WP). Serum FBG levels were considerably reduced upon short-term administration of a low daily dose of WP (< 30 g). Furthermore, the levels of serum fasting insulin were remarkably decreased during long-term supplementation with high or moderate daily doses of WP.

CONCLUSION

The findings of this study suggest that supplementation with MP may improve glycemic control in adults by reducing the values of fasting insulin, FBG, and HOMA-IR. Additional trials with longer durations are required to confirm these findings.

Probiotics and Their Role in the Management of Type 2 Diabetes Mellitus (Short-Term Versus Long-Term Effect): A Systematic Review and Meta-Analysis

Diabetes is a major economic burden and an illness with a rising incidence worldwide. Type 2 diabetes mellitus (T2DM), the most prevalent kind of diabetes, is characterized by insulin resistance and insufficient insulin production. Recent research has implicated gut microbiota dysbiosis as a contributing factor to T2DM pathogenesis. The present study employed a methodology based on randomized controlled trials (RCTs) to assess the therapeutic efficacy of probiotics in the treatment of T2DM. A thorough search was done in PubMed and Medline for articles written in English and published between 2017 and 2023. Studies were chosen based on predetermined inclusion criteria, and the search technique adhered to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) principles. This study also employed a robust assessment instrument, widely recognized in the medical and health sciences, to evaluate the potential presence of bias within the selected research studies. Out of 96 identified articles, 22 RCTs met the eligibility criteria. Both short-term (8 weeks or less) and long-term (12 weeks or more) probiotic administrations were made. The results of the meta-analysis demonstrated a significant improvement in the homeostatic model assessment of insulin resistance (HOMA-IR) following the probiotic intervention (P=0.02) and considerably decreased glycated hemoglobin HbA1c levels (P=0.004) and fasting blood glucose (FBG) levels (P<0.0001) in T2DM patients compared to placebo. This research offers proof that probiotics are clinically effective in the treatment of T2DM. Probiotic supplementation demonstrated favorable effects on glycemic control markers. However, the findings from RCTs were heterogeneous, and some studies showed inconsistent results. To clarify the processes underlying the probiotics' therapeutic benefits and to determine the best probiotic strains, doses, and therapy durations, more research is required. Nevertheless, probiotics offer a promising therapeutic approach for T2DM management and warrant consideration as a potential adjunct therapy in clinical practice.

Associations Between Serum Folate Level and HOMA-IR in Chinese Patients with Type 2 Diabetes Mellitus

Background

Adequate intake of folic acid (FA) has been proven essential for metabolism, cellular homeostasis, and antioxidant effects in diabetic patients. Our aim was to evaluate the association between serum folate levels and the risk of insulin resistance in patients with type 2 diabetes mellitus (T2DM) and to provide new ideas and approaches for reducing the risk of T2DM.

Methods

This was a case-control study involving 412 participants (206 with T2DM). Anthropometric parameters, islet function, biochemical parameters and body composition of T2DM group and control group were determined. Correlation analysis and logistic regression were used to evaluate the risk factors associated with the onset of insulin resistance in T2DM.

Results

The folate levels in type 2 diabetic patients with insulin resistance were significantly lower than those in patients without insulin resistance. Logistic regression showed that FA and high-density lipoprotein were independent influencing factors for insulin resistance in diabetic patients (P < 0.05). After adjusting for confounding factors, the degree of insulin resistance in diabetic patients was in a significant inverse relationship with folate levels (P< 0.05). We also found that below the serum FA threshold of 7.09 ng/mL insulin resistance was significantly more elevated.

Conclusion

Our findings suggest that the risk of insulin resistance increases with the decrease in serum FA levels in T2DM patients. Monitoring folate levels in these patients and FA supplementation are warranted preventive measures.

The association between serum folate and gestational diabetes mellitus: a large retrospective cohort study in Chinese population

OBJECTIVE

To investigate the association between folate levels and the risk of gestational diabetes mellitus (GDM) risk during the whole pregnancy.

DESIGN

In this retrospective cohort study of pregnant women, serum folate levels were measured before 24 gestational weeks (GW). GDM was diagnosed between 24th and 28th GW based on the criteria of the International Association of Diabetes and Pregnancy Study Groups. General linear models were performed to examine the association of serum folate with plasma glucose (i.e. linear regressions) and risk of GDM (i.e. log-binomial regressions) after controlling for confounders. Restricted cubic spline regression was conducted to test the dosage-response relationship between serum folate and the risk of GDM.

SETTING

A sigle, urban hospital in Shanghai, China.

PARTICIPANTS

A total of 42 478 women who received antenatal care from April 2013 to March 2017 were included.

RESULTS

Consistent positive associations were observed between serum folate and plasma glucose levels (fasting, 1-h, 2-h). The adjusted relative risks (RR) and 95 % CI of GDM across serum folate quartiles were 1·00 (reference), 1·15 (95 % CI (1·04, 1·26)), 1·40 (95 % CI (1·27, 1·54)) and 1·54 (95 % CI (1·40, 1·69)), respectively (P-for-trend < 0·001). The positive association between serum folate and GDM remained when stratified by vitamin B12 (adequate v. deficient groups) and the GW of serum folate measurement (≤13 GW v. >13 GWs).

CONCLUSIONS

The findings of this study may provide important evidence for the public health and clinical guidelines of pregnancy folate supplementation in terms of GDM prevention.

Estimating the serum folate concentration that corresponds to the red blood cell folate concentration threshold associated with optimal neural tube defects prevention: A population-based biomarker survey in Southern India

BACKGROUND

RBC folate concentrations are monitored at the population level, with a recommended threshold for optimal neural tube defect (NTD) prevention. A corresponding threshold for serum folate has not been established.

OBJECTIVES

This study aimed to estimate the serum folate insufficiency threshold corresponding to the RBC folate threshold for NTD prevention and examine how this threshold is modified by vitamin B12 status.

METHODS

Participants were women (15-40 y; not pregnant or lactating; n = 977) from a population-based biomarker survey in Southern India. RBC folate and serum folate were measured via microbiologic assay. RBC folate deficiency (<305 nmol/L) and insufficiency (<748 nmol/L), serum vitamin B12 deficiency (<148 pmol/L) and vitamin B12 insufficiency (<221 pmol/L), elevated plasma MMA (>0.26 μmol/L), elevated plasma homocysteine (>10.0 μmol/L), and elevated HbA1c (≥6.5%) were evaluated. Bayesian linear models were used to estimate unadjusted and adjusted thresholds.

RESULTS

Compared with adequate vitamin B12 status, the estimated serum folate threshold was higher in participants with serum vitamin B12 deficiency (72.5 vs. 28.1 nmol/L) or vitamin B12 insufficiency (48.7 vs. 24.3 nmol/L) and elevated MMA (55.6 vs. 25.9 nmol/L). The threshold was lower in participants with elevated HbA1c (HbA1c ≥6.5% vs. <6.5%; 21.0 vs. 40.5 nmol/L).

CONCLUSIONS

The estimated serum folate threshold for optimal NTD prevention was similar to previous reports (24.3 vs. 25.6 nmol/L) among participants with sufficient vitamin B12 status. However, this threshold was more than 2-fold higher in participants with vitamin B12 deficiency and substantially higher across all indicators of insufficient vitamin B12 status (<221 pmol/L, elevated MMA, combined B12, impaired vitamin B12 status), and lower in participants with elevated HbA1c. Findings suggest a serum folate threshold for NTD prevention may be possible in some settings; however, it may not be appropriate in populations with high prevalence of vitamin B12 insufficiency. Am J Clin Nutr 2023;xx:xx-xx. This trial was registered at https://clinicaltrials.gov as NCT04048330.

Effects of Folic Acid Supplementation on Liver Enzymes, Lipid Profile, and Insulin Resistance in Patients with Non-Alcoholic Fatty Liver Disease: A Randomized Controlled Trial

Background

Previous evidence revealed an association between folate deficiency and non-alcoholic fatty liver disease (NAFLD). This study is the first one investigating the effects of folic acid on hepatic steatosis grade, liver enzymes, insulin resistance, and lipid profile in NAFLD cases.

Materials and Methods

Sixty-six participants with NAFLD were allocated randomly to take either a placebo or one oral tablet of folic acid (1 mg) on a daily basis within eight weeks. Serum folate, homocysteine, glucose, aminotransferases, insulin, homeostasis model assessment of insulin resistance (HOMA-IR), and lipids were assessed. Ultrasonography was used for assessing the liver steatosis grade.

Results

The serum alanine transaminase, grade of hepatic steatosis, and aspartate transaminase significantly were decreased within both study groups; however, the between-group comparison was not statistically significant. Of note, the decrease in ALT was more pronounced in folic acid compared with the placebo group (-5.45 ± 7.45 vs. -2.19 ± 8.6 IU/L). The serum homocysteine was decreased after receiving folic acid compared to the placebo (-0.58 ± 3.41 vs. +0.4 ± 3.56 μmol/L; adjusted P = 0.054). Other outcomes did not significantly change.

Conclusion

Supplementation with folic acid (1 mg/d) for eight weeks among cases with NAFLD did not change significantly the serum levels of liver enzymes, the hepatic steatosis grade, insulin resistance and lipid profile. However, it was able to prevent the increase in homocysteine in comparison with the placebo. Conducting further research is suggested with the longer duration and different doses of folic acid, adjusted to the genotypes of methylenetetrahydrofolate reductase polymorphism, among NAFLD patients.

Folate Supplementation in Women with Pre-Existing Diabetes

Folate supplementation in the periconceptual period is the standard of care for the prevention of neural tube defects. To support dietary folate intake, some countries have introduced mandatory folic acid fortification of food products. Robust evidence supports the additional use of a low-dose folic acid supplement (0.4 mg/day) in all women from 2-3 months preconception until the end of the 12th week of gestation. For women with pre-existing diabetes, high-dose folic acid supplementation (5 mg/day) is recommended in some, but not all international guidelines. The recommendation is made based on consensus opinion and reflects the increased risk of neural tube defects in pregnant women with pre-existing diabetes. However, there is limited evidence to clarify the high-risk groups that benefit from high-dose folic acid versus those that do not. There are also some data to suggest that high-dose folic acid may be harmful to mothers and offspring, although this issue remains controversial. This narrative review explores the evidence that supports the recommendation for women with pre-existing diabetes to take high-dose folic acid in the periconceptual period. It explores the potential benefits of high-dose supplemental folate beyond the prevention of neural tube defects, and also the potential adverse impacts of high-dose folate use. These topics are considered with a specific focus on the issues that are pertinent to women with pre-existing diabetes. Based on the available evidence, a pragmatic approach to the use of folic acid supplements in women with pre-existing diabetes during the periconception period is suggested. The need for comprehensive preconception care that optimises glycaemic control and addresses other modifiable risk factors before pregnancy is emphasized.

Intended and Unintended Benefits of Folic Acid Fortification-A Narrative Review

Inadequate folate intake during pregnancy is the leading cause of the development of neural tube defects (NTDs) in newborns. For this reason, mandatory fortification of folic acid, a synthetic, easily bioavailable form, in processed cereals and cereal products has been implemented in the US since 1 January 1998 to reduce the risk of NTD in newborn children. This report aimed to review the literature related to the impact of mandated folic acid fortification on the intended and unintended benefits to health. Potential adverse effects were also discussed. We searched Pubmed, Google Scholar, Embase, SCOPUS, and Cochrane databases for reports. About 60 reports published between January 1998 and December 2022 were reviewed, summarized, and served as background for this review. The intended benefit was decreased prevalence of NTDs, while unintended benefits were reduction in anemia, blood serum homocysteine, and the risk of developing cardiovascular diseases. Potential issues with folic acid fortification are the presence of unmetabolized folic acid in circulation, increased risk of cancer, and the masking of vitamin B-12 deficiency. From a health perspective, it is important to monitor the impact of folic acid fortification periodically.

The impact of Emblica Officinalis (Amla) on lipid profile, glucose, and C-reactive protein: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND AND AIMS

Emblica Officinalis (Amla) is a plant often utilized in traditional medicine due to its purported anti-inflammatory, antioxidant, hypoglycemic, and hypolipidemic properties. However, current evidence regarding its potential for preventing and treating metabolic abnormalities associated with chronic diseases remains unclear.

METHODS

This systematic review and meta-analysis aimed to examine the effects of Amla supplementation on lipid profile, glucose, and C-reactive protein (CRP) concentrations in adults. We completed a systematic search (current as of December 2022) of all available randomized controlled trials (RCTs) in the database including ISI Web of Science, PubMed, Scopus, and Embase. Any effect's mean difference (MD) was calculated using a random-effects model. Weighted mean difference (WMD) and 95% confidence intervals (CIs) were calculated also calculated using a random-effects model.

RESULTS

Five RTCs were included in the meta-analysis. Following Amla supplementation, pooled results showed a significant reduction in CRP (p = 0.002), fasting blood glucose (FBG) (p < 0.001), low-density lipoprotein cholesterol (LDL-c) (p < 0.001), total cholesterol (TC) (p < 0.001), and serum triglyceride (TG) (p < 0.001) concentrations as well as an increase in high-density lipoprotein cholesterol (HDL-c) (p < 0.001). The baseline concentration of biochemical indicators was used for subgroup analysis.

CONCLUSION

Amla supplementation shows promise for improving metabolic parameters in adults. In general, the populations included in the analysis were generally 40-58 years with an average BMI of 25.5 and a length of intervention ranging from 3 to 12 weeks. Thus additional investigations are warranted to confirm and expand the findings presented herein.

The effects of folic acid supplementation on endothelial function in adults: a systematic review and dose-response meta-analysis of randomized controlled trials

BACKGROUND

Endothelial dysfunction serves as an early marker for the risk of cardiovascular disease (CVD); therefore, it is an attractive site of therapeutic interventions to reduce the risk of CVD. This study was conducted to investigate the effect of folic acid supplementation on endothelial function markers in randomized controlled trials (RCTs).

METHODS

PubMed, ISI web of science, and Scopus databases were searched up to July 2022 for detecting eligible studies. A random-effects model was used for meta-analysis, and linear Meta-regression and non-linear dose-response analysis were performed to assess whether the effect of folic acid supplementation was affected by the dose and duration of intervention. Cochrane tools were also used to assess the risk of bias in the included studies.

RESULTS

Twenty-one studies, including 2025 participants (1010 cases and 1015 controls), were included in the present meta-analysis. Folic acid supplementation significantly affected the percentage of flow-mediated dilation (FMD%) (WMD: 2.59%; 95% CI: 1.51, 3.67; P < 0.001) and flow-mediated dilation (FMD) (WMD: 24.38 μm; 95% CI: 3.08, 45.68; P = 0.025), but not end-diastolic diameter (EDD) (WMD: 0.21 mm; 95% CI: - 0.09, 0.52; P = 0.176), and intercellular adhesion molecule (ICAM) (WMD: 0.18 ng/ml; 95% CI: - 10.02, 13.81; P = 0.755).

CONCLUSIONS

These findings suggest that folic acid supplementation may improve endothelial function by increasing FMD and FMD% levels.

TRIAL REGISTRATION

PROSPERO registration cod: CRD42021289744.

Efficacy and safety of Obex® in overweight and obese subjects: a randomised, double-blind, placebo-controlled clinical trial

BACKGROUND

Obex® may be helpful in reducing body weight and fat. The current study was carried out to evaluate the efficacy and safety of Obex® in the treatment of overweight and obese subjects.

METHODS

A double-blind, randomised, controlled phase III clinical trial was conducted involving 160 overweight and obese subjects (BMI ≥ 25.0 and < 40 kg/m²) aged 20 to 60 years, who received Obex® (n = 80) and placebo (n = 80) plus non-pharmacological treatment (physical activity and nutritional counseling). One sachet of Obex® or placebo were administered before the two main meals each day for 6 months. In addition to anthropometric measurements and blood pressure, fasting plasma and 2 h glucose levels during the oral glucose tolerance test, lipid profile, insulin, liver enzymes, creatinine, and uric acid (UA) were determined, insulin resistance (HOMA-IR) beta-cell function (HOMA-β) were assessed and insulin sensitivity (IS) was calculated with three indirect indexes.

RESULTS

After 3 months of Obex®, 48.3% of the participants (28/58) achieved complete success in reducing both weight and waist circumference by greater than or equal to 5% from baseline, as opposed to 26.0% (13/50) of individuals receiving placebo (p = 0.022). Compared to baseline, at 6 months no differences were found between the groups concerning anthropometric and biochemical measurements, except for high-density lipoprotein cholesterol (HDL-c) levels, which were higher in subjects receiving Obex® compared to those receiving placebo (p = 0.030). After 6 months of treatment, both groups showed reduced cholesterol and triglyceride levels (p < 0.012) compared to baseline value. However, only those intake Obex® showed reduced insulin concentrations and HOMA-IR, improved IS (p < 0.05), and decreased creatinine and UA levels (p < 0.005).

CONCLUSIONS

The consumption of Obex® together with lifestyle changes increased HDL-c, contributed to a rapid reduction of weight and waist circumference, as well as improved insulin homeostasis, which did not occur in the placebo group, and appears to be safe as an adjunct at conventional obesity treatment.

TRIAL REGISTRATION

Clinical trial protocol was registered in the Cuban public registry of clinical trials under code RPCEC00000267 on 17/04/2018 and also registered in the international registry of clinical trials, ClinicalTrials.gov, under code: NCT03541005 on 30/05/2018.

The effects of green tea supplementation on cardiovascular risk factors: A systematic review and meta-analysis

Purpose

A bulk of observational studies have revealed the protective role of green tea supplementation in cardiovascular diseases. The current systematic review and meta-analysis study aimed to establish the effects of green tea supplementation on cardiovascular risk factors including lipid profile, blood pressure, glycemic control markers and CRP.

Methods

A systematic literature search of randomized clinical trials (RCTs) that investigated the effects of green tea supplementation and cardiovascular risk factors was undertaken in online databases including PubMed/Medline, Scopus, Web of Science, and Embase using a combination of green tea and cardiovascular risk factors search terms. Meta-analyses were carried out using a random-effects model. The I2 index was used to assess the heterogeneity of RCTs.

Results

Among the initial 11,286 studies that were identified from electronic databases search, 55 eligible RCTs with 63 effect sizes were eligible. Results from the random effects meta-analysis showed that GTE supplementation significantly reduced TC (WMD = -7.62; 95% CI: -10.51, -4.73; P = < 0.001), LDL-C (WMD = -5.80; 95% CI: -8.30, -3.30; P = < 0.001), FBS (WMD = -1.67; 95% CI: -2.58, -0.75; P = < 0.001), HbA1c (WMD = -0.15; 95% CI: -0.26, -0.04; P = 0.008), DBP (WMD = -0.87; 95% CI: -1.45, -0.29; P = 0.003), while increasing HDL-C (WMD = 1.85; 95% CI: 0.87, 2.84; P = 0.010). Subgroup analyses based on the duration of supplementation (≥ 12 vs. < 12 weeks), dose of green tea extract (GTE) (≥1,000 vs. < 1,000 mg/d), sex (male, female, and both), baseline serum levels of lipid profile, and glycemic control factors demonstrated different results for some risk factors.

Conclusion

The current study suggests improvements in the lipid and glycemic profiles following green tea supplementation. These findings support previous evidence showing the health benefits of green tea supplementation on cardiometabolic risk factors.

The effects of L-carnitine supplementation on glycemic markers in adults: A systematic review and dose-response meta-analysis

Background and aims

Hyperglycemia and insulin resistance are concerns today worldwide. Recently, L-carnitine supplementation has been suggested as an effective adjunctive therapy in glycemic control. Therefore, it seems important to investigate its effect on glycemic markers.

Methods

PubMed, Scopus, Web of Science, and the Cochrane databases were searched in October 2022 for prospective studies on the effects of L-carnitine supplementation on glycemic markers. Inclusion criteria included adult participants and taking oral L-carnitine supplements for at least seven days. The pooled weighted mean difference (WMD) was calculated using a random-effects model.

Results

We included the 41 randomized controlled trials (RCTs) (n = 2900) with 44 effect sizes in this study. In the pooled analysis; L-carnitine supplementation had a significant effect on fasting blood glucose (FBG) (mg/dl) [WMD = -3.22 mg/dl; 95% CI, -5.21 to -1.23; p = 0.002; I ² = 88.6%, p < 0.001], hemoglobin A1c (HbA1c) (%) [WMD = -0.27%; 95% CI, -0.47 to -0.07; p = 0.007; I ² = 90.1%, p < 0.001] and homeostasis model assessment-estimate insulin resistance (HOMA-IR) [WMD = -0.73; 95% CI, -1.21 to -0.25; p = 0.003; I ² = 98.2%, p < 0.001] in the intervention compared to the control group. L-carnitine supplementation had a reducing effect on baseline FBG ≥100 mg/dl, trial duration ≥12 weeks, intervention dose ≥2 g/day, participants with overweight and obesity (baseline BMI 25-29.9 and >30 kg/m²), and diabetic patients. Also, L-carnitine significantly affected insulin (pmol/l), HOMA-IR (%), and HbA1c (%) in trial duration ≥12 weeks, intervention dose ≥2 g/day, and participants with obesity (baseline BMI >30 kg/m²). It also had a reducing effect on HOMA-IR in diabetic patients, non-diabetic patients, and just diabetic patients for insulin, and HbA1c. There was a significant nonlinear relationship between the duration of intervention and changes in FBG, HbA1c, and HOMA-IR. In addition, there was a significant nonlinear relationship between dose (≥2 g/day) and changes in insulin, as well as a significant linear relationship between the duration (weeks) (coefficients = -16.45, p = 0.004) of intervention and changes in HbA1C.

Conclusions

L-carnitine could reduce the levels of FBG, HbA1c, and HOMA-IR.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier: CRD42022358692.

Maternal micronutrient disturbance as risks of offspring metabolic syndrome

Metabolic syndrome (MetS) is defined as a constellation of individual metabolic disturbances, including central obesity, hypertension, dyslipidemia, and insulin resistance. The established pathogenesis of MetS varies extensively with gender, age, ethnic background, and nutritional status. In terms of nutritional status, micronutrients are more likely to be discounted as essential components of required nutrition than macronutrients due to the small amount required. Numerous observational studies have shown that pregnant women frequently experience malnutrition, especially in developing and low-income countries, resulting in chronic MetS in the offspring due to the urgent and increasing demands for micronutrients during gestation and lactation. Over the past few decades, scientific developments have revolutionized our understanding of the association between balanced maternal micronutrients and MetS in the offspring. Examples of successful individual, dual, or multiple maternal micronutrient interventions on the offspring include iron for hypertension, selenium for type 2 diabetes, and a combination of folate and vitamin D for adiposity. In this review, we aim to elucidate the effects of maternal micronutrient intake on offspring metabolic homeostasis and discuss potential perspectives and challenges in the field of maternal micronutrient interventions.

Dietary intake of folate and the frequency of its deficiency in children with type 1 diabetes mellitus and healthy children

Adequate folate intake is essential for a child’s growth. There is lack of information about the prevalence of this nutrient deficiency in the Ukrainian population, including children. The aim of the study was to evaluate the dietary intake of folate and determine the frequency of folate deficiency in children with Type 1 diabetes mellitus (T1D) and healthy children. Determination of folate in serum was performed by ELISA. Folate level <3 ng/ml was diagnosed as a folate deficiency. Among all observed children the folate deficiency was diagnosed in 23 (32.9%): in 6 (17.1%) patients with T1D and in 17 (48.6%) healthy children (P ≤ 0.01). The mean level of serum folate in patients with T1D was (5.09 ± 2.16) ng/ml and (3.72 ± 1.87) ng/ml in healthy children (P ≤ 0.01). The average daily intake of folate with food was (138.68 ± 70.37) µg, without difference between T1D (12.00 ± 3.51 yr.) and healthy groups (10.83 ± 3.24 yr.), and it was more than two times lower than age requirements (300 µg/day). However, it was self-reported that 15 (48.9%) children of T1D group received vitamin supplementation one time in six months, while in healthy children only 6 (17.1%) children received vitamins (P ≤ 0.01). In conclusion, the frequency of folate deficiency is high in the pediatric population. Nutrition does not provide the necessary intake of folate, which indicates the need for additional folate supplementation. Keywords: children., deficiency, diabetes mellitus, dietary intake, folate

Associations of folate intake with all-cause and cause-specific mortality among individuals with diabetes

Background and aims

The evidence regarding folate intake and mortality risk among patients with type 2 diabetes (T2D) remains unclear. This study aimed to investigate the association of folate intake with the risk of mortality among individuals with T2D.

Methods

A total of 9,196 participants with T2D from the Third National Health and Nutrition Examination Survey (NHANES III) and NHANES 1999–2014 were included. The data of survival were obtained by the cohort database linked with the national death index up to 31 December 2015. The Cox proportional hazard model was used to evaluate the relationship between dietary folate with all-cause and cause-specific mortality.

Results

Among patients with T2D, dietary folate intake was negatively correlated with all-cause mortality, cardiovascular mortality, and cancer mortality in men, and for women with all-cause mortality and cardiovascular mortality. The multivariate adjustment hazard ratio (HR) (95% CIs) for men of highest vs. lowest quartile was 0.77 (0.66–0.90), 0.61 (0.45–0.83), and 0.70 (0.49–0.99) for all-cause, cardiovascular, and cancer mortality, respectively. Among women, the multivariate adjustment HR (95% CIs) of highest vs. lowest quartile was 0.77 (0.64–0.92), 0.52 (0.33–0.83), and 0.78 (0.50–1.22) for all-cause, cardiovascular, and cancer mortality, respectively.

Conclusion

Higher dietary intake of folate was significantly associated with lower all-cause and cardiovascular mortality. This cohort study suggested that increasing the dietary folate intake may reduce mortality risk among U.S. adults with T2D.

Association between dietary intake of one-carbon metabolism nutrients and hyperglycemia in coal-burning fluorosis areas of Guizhou, China

Background and aims

There are limited studies describing the association between dietary intake of one-carbon metabolism nutrients and hyperglycemia. The present study aimed to investigate the association of habitual dietary intake of one-carbon metabolism nutrients with hyperglycemia in a fluorosis area in China, and explored the interaction between these nutrients and fluorosis related to hyperglycemia.

Method

In a cross-sectional study, we recruited 901 villagers, ages ranging from 18–75, in Guizhou Province. Dietary data and other covariate data were obtained through an interviewer-administered questionnaire. We collected venous blood samples from participants who had fasted for one night to obtain fasting blood glucose levels and we categorized dietary intake of betaine, total choline, methionine, folate, vitamins B₆ and B₁₂, and choline subclasses into quartiles (Q1–Q4). The lowest quartile (Q1) served as the reference group. An unconditional logistic regression model was used to evaluate the protective effects of a dietary intake of one-carbon nutrients against hyperglycemia. We calculated Odds Ratios (ORs) with 95% confidence intervals (CIs). A presence or absence of fluorosis subgroup analysis was performed to determine the potential effect of fluorosis on hyperglycemia.

Result

After adjusting for potential confounding factors, we found that a greater intake of dietary vitamin B₆, total choline and methyl-donor index was inversely associated with the occurrence of hyperglycemia (P-trend <0.05). However, there were no significant associations between hyperglycemia and the dietary intake of folate, vitamin B₁₂, methionine, and betaine. As for the choline subgroups, it showed that the dietary intake of free choline, phosphatidylcholine, and glycerol phosphatidylcholine was negatively correlated with the occurrence of hyperglycemia (P < 0.05). In contrast, there was no statistical association between dietary phosphatidylcholine and sphingomyelin and hyperglycemia (all P > 0.05). The results of subgroup analysis showed that dietary intake of folate, vitamin B₆, total choline, free choline, glycerol phosphorylcholine, and phosphocholine had a protective effect against the occurrence of hyperglycemia in the non-fluorosis subgroup, although no effects were observed in the fluorosis subgroup. There were significant interactions between these nutrients and fluorosis (P = 0.010–0.048).

Conclusion

The study demonstrated that higher dietary intake of vitamin B₆, total choline, methyl-donor index, free choline, glycerol phosphorylcholine, and phosphocholine in choline compounds were associated with a lower incidence of hyperglycemia. Moreover, the associations were modified by the presence or absence of fluorosis. Further investigation is needed to test the association in large-scale follow-up studies.

Diet and Maternal Obesity Are Associated with Increased Oxidative Stress in Newborns: A Cross-Sectional Study

Overweight and obesity have become a world-health public problem, mainly for developing countries. Both health conditions have a higher prevalence among women of childbearing age. Physiopathology, overweight and obesity are characterized by a chronic oxidative stress status, which has deleterious effects on mothers and children. Hence, we determine whether the qualities of diet during pregnancy and maternal pregestational body mass index (BMI) are associated with increased oxidative stress markers in mothers and newborns. Two hundred forty-two (242) mother-newborn pairs were classified according to their pregestational BMI. Information on food intake was collected using a food frequency questionnaire in the third trimester of pregnancy. Levels of Malondialdehyde (MDA) and Nitric Oxide (NO) were measured in plasma from mothers at the end of the third trimester of pregnancy and from cord blood at birth. MDA and NO levels in mother–newborn pairs with maternal pregestational overweight or obesity were higher than in mother–newborn pairs with pregestational normal weight. For women (and newborns) who had a higher intake of fruit and vegetables, the levels of NO and MDA were lower. Lastly, women with pregestational obesity had lower fruit and vegetable intake during pregnancy and higher levels of oxidative stress and in their newborns.

The effects of dietary supplements and natural products targeting glucose levels: an overview

Identifying effective dietary supplements and medicinal herbs has attracted the attention of clinicians and researchers to complement the standard treatment in controlling diabetes mellitus. In the present overview, we aimed to collect studies with the highest level of evidence to shed light on detecting the most effective dietary supplements and medicinal herbs for controlling glycemic status. For the current overview, four electronic databases, including PubMed, Scopus, Web of Science, and Cochrane Library, were systematically searched from inception to 31 December 2020 and then updated until 1 October 2021 to obtain eligible meta-analyses on either dietary supplements or medicinal herbs and their effects on glycemic status. Fasting blood sugar (FBS) and Hemoglobin A1C (HbA1C) were considered as primary outcomes. Finally, ninety-one meta-analyses on dietary supplements (n = 55) and herbs (n = 36) were included. Evidence showed positive effects of chromium, zinc, propolis, aloe vera, milk thistle, fenugreek, cinnamon, ginger, and nettle on FBS and/or HbA1C. However, mostly the heterogeneity (I2) was high. Other supplements and herbs also showed no reduction in glucose levels or their effects were small. Although some dietary supplements and medicinal herbs showed a significant reduction in FBS and/or HbA1C, mostly their effects from the clinical point of view were not remarkable. In addition, due to high heterogeneity, publication bias, and a limited number of included studies in most cases further clinical trials are needed for making decision on anti-diabetic supplement efficacy.

The Effects of Saffron (Crocus sativus L.) in conjunction with Concurrent Training on body composition, glycemic status, and inflammatory markers in obese men with type 2 diabetes mellitus: a randomized double-blind clinical trial

AIM

Chronic inflammation is one of the major challenges in the management of obesity and type 2 diabetes mellitus (T2DM). Our primary aim was to assess the anti-inflammatory effects of Saffron (Crocus sativus L.) supplementation and concurrent training in obese men with T2DM.

METHODS

Sixty obese men with T2DM (age = 39 ± 5 years; body mass = 93.9 ± 6 kg) were randomly assigned to four groups; concurrent training + placebo (CT; n = 15), saffron supplementation (S; n = 15), concurrent training + saffron supplementation (CTS; n = 15), or control (CON; n = 15). The participants in the CT group performed concurrent training (resistance + aerobic) three times per week for 12 weeks and received daily one pill of placebo (maltodextrin); the participants in the S group supplemented with one pill of 100 mg of saffron daily, and the participants in the CTS group participated in both saffron and training intervention while CON group continued regular lifestyle (no training or no supplementation). Inflammatory markers, body composition (evaluated by a multi-frequency bioelectrical impedance device; Jawon X-Contact 356), and metabolic profile were evaluated before and after interventions.

RESULTS

All three interventions significantly (p<0.05) decreased TNF-α (CT = -4.22, S = -1.91, CTS = -9.69 pg/mL), hs-CRP (CT = -0.13, S = -0.1, CTS = -0.32 ng/mL), IL-6 (CT = -6.84, S = -6.36, CTS = -13.55 pg/mL), IL-1β (CT = -8.85, S = -6.46, CTS = -19.8 pg/mL), FBG (CT = -6.97, S = -2.45, CTS = -13.86 mg/dL), insulin (CT = -0.13, S = -0.03, CTS = -0.21 mU/L), HOMA-IR (CT = -0.12, S = -0.04, CTS = -0.21), HbA1c (CT = -0.17, S = -0.11, CTS = -0.26 %), and increased IL-10 (CT = 1.09, S= 0.53, CTS = 2.27 pg/mL) concentrations. There was a positive correlation between changes in BFP with hs-CRP, IL-6, IL-1β, and TNF-α, and IL-10 concentrations across the intervention groups. Additionally, significant differences were observed between the changes for all variables in the CTS group compared to CT, S, and CON groups (p<0.05) CONCLUSION: It seems that an interactive of saffron supplementation and concurrent training has more efficient effects on the anti-inflammatory status compared to the saffron supplementation or concurrent training alone.

The Effects of Magnesium Supplementation on Serum Magnesium and Calcium Concentration in Patients With Type 2 Diabetes: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

The aim of this systematic review and meta-analysis was to summarize all the existing randomized controlled trials (RCTs) evidence and to evaluate the effects of magnesium supplementation on serum magnesium, calcium and urinary magnesium concentrations in patients with type 2 diabetes compared with the control. Two independent authors systematically searched online databases including Embase, Scopus, PubMed, and Web of Science from inception until 30th January 2022. RCTs complying with the inclusion criteria were included in this meta-analysis. The heterogeneity among the included studies was assessed using Cochrane’s Q test and I-square (I²) statistic. Data were pooled using a random-effects model and weighted mean difference (WMD) was considered as the overall effect size. Sixteen trials were included in this meta-analysis. Serum magnesium (mean difference, 0.15 mg/dL; 95% confidence interval [CI], 0.06 to 0.23; p = 0.001) and urinary magnesium (WMD, 1.99 mg/dL; 95% CI, 0.36 to 3.62; p = 0.017) concentrations were significantly increased after magnesium supplementation when compared with the control group. However, magnesium supplementation did not have any significant effect on serum calcium (WMD, −0.09 mg/dL; 95% CI, −0.27 to 0.08; p = 0.294) level when compared with the control group. This meta-analysis demonstrated that magnesium supplementation significantly increased Serum magnesium levels which may have played an indirect role in improved clinical symptoms in patients with type 2 diabetes.

Is Arsenic Exposure a Risk Factor for Metabolic Syndrome? A Review of the Potential Mechanisms

Exposure to arsenic in drinking water is a worldwide health problem. This pollutant is associated with increased risk of developing chronic diseases, including metabolic diseases. Metabolic syndrome (MS) is a complex pathology that results from the interaction between environmental and genetic factors. This condition increases the risk of developing type 2 diabetes, cardiovascular diseases, and cancer. The MS includes at least three of the following signs, central obesity, impaired fasting glucose, insulin resistance, dyslipidemias, and hypertension. Here, we summarize the existing evidence of the multiple mechanisms triggered by arsenic to developing the cardinal signs of MS, showing that this pollutant could contribute to the multifactorial origin of this pathology.

Role of Vitamin B12 and Folate in Metabolic Syndrome

Metabolic syndrome (MS) is a collection of pathological metabolic conditions that includes insulin resistance, central or abdominal obesity, dyslipidemia, and hypertension. It affects large populations worldwide, and its prevalence is rising exponentially. There is no specific mechanism that leads to the development of MS. Proposed hypotheses range from visceral adiposity being a key factor to an increase in very-low-density lipoprotein and fatty acid synthesis as the primary cause of MS. Numerous pharmaceutical therapies are widely available in the market for the treatment of the individual components of MS. The relationship between MS and vitamin B complex supplementation, specifically folic acid and vitamin B12, has been a subject of investigation worldwide, with several trials reporting a positive impact with vitamin supplementation on MS.

In this study, an all-language literature search was conducted on Medline, Cochrane, Embase, and Google Scholar till September 2021. The following search strings and Medical Subject Headings (MeSH) terms were used: “Vitamin B12,” “Folate,” “Metabolic Syndrome,” and “Insulin Resistance.” We explored the literature on MS for its epidemiology, pathophysiology, newer treatment options, with a special focus on the effectiveness of supplementation with vitamins B9 and B12.

According to the literature, vitamin B12 and folate supplementation, along with a host of novel therapies, has a considerable positive impact on MS. These findings must be kept in mind while designing newer treatment protocols in the future.