Thiamine deficiency in diabetes mellitus and the impact of thiamine replacement on glucose metabolism and vascular disease

Astragalus Polysaccharide Modulates the Gut Microbiota and Metabolites of Patients with Type 2 Diabetes in an In Vitro Fermentation Model

This study investigated the effect of astragalus polysaccharide (APS, an ingredient with hypoglycemic function in a traditional Chinese herbal medicine) on gut microbiota and metabolites of type 2 diabetes mellitus (T2DM) patients using a simulated fermentation model in vitro. The main components of APS were isolated, purified, and structure characterized. APS fermentation was found to increase the abundance of Lactobacillus and Bifidobacterium and decrease the Escherichia-Shigella level in the fecal microbiota of T2DM patients. Apart from increasing propionic acid, APS also caused an increase in all-trans-retinoic acid and thiamine (both have antioxidant properties), with their enrichment in the KEGG pathway associated with thiamine metabolism, etc. Notably, APS could also enhance fecal antioxidant properties. Correlation analysis confirmed a significant positive correlation of Lactobacillus with thiamine and DPPH-clearance rate, suggesting the antioxidant activity of APS was related to its ability to enrich some specific bacteria and upregulate their metabolites.

Thiamine deficiency in diabetes, obesity and bariatric surgery: Recipes for diabetic ketoacidosis

Diabetic ketoacidosis (DKA) is a life-threatening condition affecting individuals with diabetes characterised by hyperglycaemia, metabolic acidosis and ketonemia. The incidence and financial burden of DKA is still high. Thiamine deficiency is well documented in patients with DKA and could be associated with cardiac dysfunction in those patients. Thiamine deficiency leads to cardiac dysfunction, neuronal death and worsens the prognosis of DKA. There is an existing metabolic relationship between thiamine deficiency in diabetes, obesity and bariatric surgery. Careful monitoring of thiamine, along with other vitamins, is essential for diabetic patients, obese individuals and postbariatric surgery. Further research and clinical studies are urgently needed to assess the following: (1) Whether diabetes, obesity and bariatric surgery make individuals more prone to have DKA related to thiamine deficiency and (2) Whether supplementation of thiamine can protect diabetic patients, obese subjects and individuals undergoing bariatric surgery from DKA. This review summarises the biochemistry of thiamine and the existing metabolic relationships between thiamine deficiency in DKA, diabetes, obesity and bariatric surgery. Primary and family physicians have an important role in ensuring adequate replacement of thiamine in individuals with diabetes, obesity and bariatric surgery.

Cardiovascular disease in low- and middle-income countries associated with environmental factors

There is a growing recognition that the profound environmental changes that have occurred over the past century pose threats to human health. Many of these environmental factors, including air pollution, noise pollution, as well as exposure to metals such as arsenic, cadmium, lead, and other metals, are particularly detrimental to the cardiovascular health of people living in low-to-middle income countries (LMICs). Low-to-middle income countries are likely to be disproportionally burdened by cardiovascular diseases provoked by environmental factors. Moreover, they have the least capacity to address the core drivers and consequences of this phenomenon. This review summarizes the impact of environmental factors such as climate change, air pollution, and metal exposure on the cardiovascular system, and how these specifically affect people living in LMICs. It also outlines how behaviour changes and interventions that reduce environmental pollution would have significant effects on the cardiovascular health of those from LMICs, and globally.

Thiamine and benfotiamine: Focus on their therapeutic potential

Thiamine, also known as vitamin B1, is an essential nutrient that plays a crucial role in energy metabolism and overall health. It is a water-soluble vitamin that plays an important role in the conversion of carbohydrates into energy in the body. Thiamine is essential for the proper functioning of the nervous system, heart and muscles. Thiamine deficiency is a life-threatening disease that leads to various disorders and lesions in the nerves and brain, at least in vertebrates. Several thiamine precursors with higher bioavailability have been developed to compensate for thiamine deficiency, including benfotiamine. Benfotiamine is more bioavailable and has higher tissue penetration than thiamine. Studies have shown its antioxidant and anti-inflammatory potential in activated immune and glial cells. It also improves complications observed in type 2 diabetes and has beneficial effects in mouse models of neurodegenerative disease. Benfotiamine represents an off-the-shelf agent used to support nerve health, promote healthy aging and support glucose metabolism. Accordingly, the present review aimed to provide an overview of the neuroprotective effects of thiamine/benfotiamine in the context of inflammation and oxidative stress.

The importance of thiamine (vitamin B1) in humans

Thiamine (thiamin, B1) is a vitamin necessary for proper cell function. It exists in a free form as a thiamine, or as a mono-, di- or triphosphate. Thiamine plays a special role in the body as a coenzyme necessary for the metabolism of carbohydrates, fats and proteins. In addition, it participates in the cellular respiration and oxidation of fatty acids: in malnourished people, high doses of glucose result in acute thiamine deficiency. It also participates in energy production in the mitochondria and protein synthesis. In addition, it is also needed to ensure the proper functioning of the central and peripheral nervous system, where it is involved in neurotransmitter synthesis. Its deficiency leads to mitochondrial dysfunction, lactate and pyruvate accumulation, and consequently to focal thalamic degeneration, manifested as Wernicke's encephalopathy or Wernicke-Korsakoff syndrome. It can also lead to severe or even fatal neurologic and cardiovascular complications, including heart failure, neuropathy leading to ataxia and paralysis, confusion, or delirium. The most common risk factor for thiamine deficiency is alcohol abuse. This paper presents current knowledge of the biological functions of thiamine, its antioxidant properties, and the effects of its deficiency in the body.

Extracellular thiamine concentration influences thermogenic competency of differentiating neck area-derived human adipocytes

Introduction

Brown adipose tissue (BAT) dissipates energy in the form of heat majorly via the mitochondrial uncoupling protein 1 (UCP1). The activation of BAT, which is enriched in the neck area and contains brown and beige adipocytes in humans, was considered as a potential therapeutic target to treat obesity. Therefore, finding novel agents that can stimulate the differentiation and recruitment of brown or beige thermogenic adipocytes are important subjects for investigation. The current study investigated how the availability of extracellular thiamine (vitamin B1), an essential cofactor of mitochondrial enzyme complexes that catalyze key steps in the catabolism of nutrients, affects the expression of thermogenic marker genes and proteins and subsequent functional parameters during ex vivo adipocyte differentiation.

Methods

We differentiated primary human adipogenic progenitors that were cultivated from subcutaneous (SC) or deep neck (DN) adipose tissues in the presence of gradually increasing thiamine concentrations during their 14-day differentiation program. mRNA and protein expression of thermogenic genes were analyzed by RT-qPCR and western blot, respectively. Cellular respiration including stimulated maximal and proton-leak respiration was measured by Seahorse analysis.

Results

Higher thiamine levels resulted in increased expression of thiamine transporter 1 and 2 both at mRNA and protein levels in human neck area-derived adipocytes. Gradually increasing concentrations of thiamine led to increased basal, cAMP-stimulated, and proton-leak respiration along with elevated mitochondrial biogenesis of the differentiated adipocytes. The extracellular thiamine availability during adipogenesis determined the expression levels of UCP1, PGC1a, CKMT2, and other browning-related genes and proteins in primary SC and DN-derived adipocytes in a concentration-dependent manner. Providing abundant amounts of thiamine further increased the thermogenic competency of the adipocytes.

Discussion

Case studies in humans reported that thiamine deficiency was found in patients with type 2 diabetes and obesity. Our study raises the possibility of a novel strategy with long-term thiamine supplementation, which can enhance the thermogenic competency of differentiating neck area-derived adipocytes for preventing or combating obesity.

Impact of dietary interventions on pre-diabetic oral and gut microbiome, metabolites and cytokines

Diabetes and associated comorbidities are a global health threat on the rise. We conducted a six-month dietary intervention in pre-diabetic individuals (NCT03222791), to mitigate the hyperglycemia and enhance metabolic health. The current work explores early diabetes markers in the 200 individuals who completed the trial. We find 166 of 2,803 measured features, including oral and gut microbial species and pathways, serum metabolites and cytokines, show significant change in response to a personalized postprandial glucose-targeting diet or the standard of care Mediterranean diet. These changes include established markers of hyperglycemia as well as novel features that can now be investigated as potential therapeutic targets. Our results indicate the microbiome mediates the effect of diet on glycemic, metabolic and immune measurements, with gut microbiome compositional change explaining 12.25% of serum metabolites variance. Although the gut microbiome displays greater compositional changes compared to the oral microbiome, the oral microbiome demonstrates more changes at the genetic level, with trends dependent on environmental richness and species prevalence in the population. In conclusion, our study shows dietary interventions can affect the microbiome, cardiometabolic profile and immune response of the host, and that these factors are well associated with each other, and can be harnessed for new therapeutic modalities.

Dietary factors potentially impacting thiaminase I-mediated thiamine deficiency

Fish population declines from thiamine (vitamin B1) deficiency have been widespread in ecologically and economically valuable organisms, ranging from the Great Lakes to the Baltic Sea and, most recently, the California coast. Thiamine deficiencies in predatory fishes are often attributed to a diet of prey fishes with high levels of thiamine-degrading (e.g., thiaminase) enzymes, such as alewives, rainbow smelt, and anchovies. Since their discovery, thiaminase I enzymes have been recognized for breaking down thiamine into its pyrimidine and thiazole moieties using various nucleophilic co-substrates to afford cleavage, but these studies have not thoroughly considered other factors that could modify enzyme activity. We found the thiaminase I enzyme from Clostridium botulinum efficiently degrades thiamine in the presence of pyridoxine (vitamin B6) as a co-substrate but has relatively limited activity in the presence of nicotinic acid (vitamin B3). Using fluorescence measurements, thiamine degradation in an over-the-counter complete multivitamin formulation was inhibited, and a B-complex formulation required co-substrate supplementation for maximal thiamine depletion. These studies prompted the evaluation of specific constituents contributing to thiaminase I inhibition by both chromatography and fluorescence assays: Cu²⁺ potently and irreversibly inhibited thiamine degradation; ascorbic acid was a strong but reversible inhibitor; Fe²⁺, Mn²⁺ and Fe³⁺ modulated thiamine degradation to a lesser degree. The enhancement by pyridoxine and inhibition by Cu²⁺ extended to thiaminase-mediated degradation from Burkholderia thailandensis, Paenibacillus thiaminolyticus, and Paenibacillus apiarius in tryptic soy broth supernatants. These co-substrate limitations and the common presence of inhibitory dietary factors complement recent studies reporting that the intended function of thiaminase enzymes is to recycle thiamine breakdown products for thiamine synthesis, not thiamine degradation.

Association between diabetes and thiamine status - A systematic review and meta-analysis

BACKGROUND

Thiamine (vitamin B1) is an essential cofactor in glucose metabolism, but it remains unclear whether thiamine status is lower in individuals with diabetes compared to individuals with normal glucose metabolism.

AIMS

We conducted a systematic review and meta-analysis to study whether the circulating concentrations of various thiamine analytes differ between people with and those without diabetes.

METHODS

PubMed and the Cochrane Central Register of Controlled Trials were searched according to the study protocol. The standardized mean difference (SMD) and 95 % confidence intervals (CI) of thiamine markers between individuals with and without diabetes were used as effect size (random effects model). Subgroup analysis considered albuminuria as an additional variable.

RESULTS

Out of the 459 articles identified, 24 full-texts were eligible for the systematic review, 20 of which qualified for the data analysis and four were evaluated for coherence. Compared to controls, individuals with diabetes showed lower concentrations of thiamine (pooled estimate SMD [95 % CI]: -0.97 [-1.89, -0.06]), thiamine monophosphate (-1.16 [-1.82, -0.50]), and total thiamine compounds (-1.01 [-1.48, -0.54]). Thiamine diphosphate (-0.72 [-1.54, 0.11] and erythrocyte transketolase activity (-0.42 [-0.90, 0.05]) tended to be lower in persons with diabetes than in controls without reaching statistical significance. Subgroup analysis showed that individuals with diabetes and albuminuria had lower thiamine levels than the controls (-2.68 [-5.34, -0.02]).

CONCLUSIONS

Diabetes is associated with lower levels of various thiamine markers, suggesting that individuals with diabetes may have higher thiamine requirements than those without diabetes, but well-designed studies are required to confirm these findings.

Physiological Associations between Vitamin B Deficiency and Diabetic Kidney Disease

The number of people living with chronic kidney disease (CKD) is growing as our global population continues to expand. With aging, diabetes, and cardiovascular disease being major harbingers of kidney disease, the number of people diagnosed with diabetic kidney disease (DKD) has grown concurrently. Poor clinical outcomes in DKD could be influenced by an array of factors-inadequate glycemic control, obesity, metabolic acidosis, anemia, cellular senescence, infection and inflammation, cognitive impairment, reduced physical exercise threshold, and, importantly, malnutrition contributing to protein-energy wasting, sarcopenia, and frailty. Amongst the various causes of malnutrition in DKD, the metabolic mechanisms of vitamin B (B1 (Thiamine), B2 (Riboflavin), B3 (Niacin/Nicotinamide), B5 (Pantothenic Acid), B6 (Pyridoxine), B8 (Biotin), B9 (Folate), and B12 (Cobalamin)) deficiency and its clinical impact has garnered greater scientific interest over the past decade. There remains extensive debate on the biochemical intricacies of vitamin B metabolic pathways and how their deficiencies may affect the development of CKD, diabetes, and subsequently DKD, and vice-versa. Our article provides a review of updated evidence on the biochemical and physiological properties of the vitamin B sub-forms in normal states, and how vitamin B deficiency and defects in their metabolic pathways may influence CKD/DKD pathophysiology, and in reverse how CKD/DKD progression may affect vitamin B metabolism. We hope our article increases awareness of vitamin B deficiency in DKD and the complex physiological associations that exist between vitamin B deficiency, diabetes, and CKD. Further research efforts are needed going forward to address the knowledge gaps on this topic.

Addressing Cognitive Biases in Interpreting an Elevated Lactate in a Patient with Type 1 Diabetes and Thiamine Deficiency

We present the case of a young woman admitted for diabetic ketoacidosis with persistent, asymptomatic lactic acid (LA) elevation during the evolving COVID-19 pandemic. Cognitive biases in interpreting an elevated LA in this patient's care resulted in an extensive infectious workup instead of the low-cost and potentially diagnostic provision of empiric thiamine. We discuss clinical patterns and etiologies of LA elevation and the role of thiamine deficiency. We also address cognitive biases potentially affecting the interpretation of elevated lactate levels and provide guidance for clinicians to determine appropriate patients for empiric thiamine administration.

A critical review of the relationship between type 1 diabetes mellitus, inhibition, and behavioral management

Type 1 diabetes mellitus (T1DM) is a chronic and lifelong condition that requires adequate behavior management in order to meet desired health outcomes. The effects of T1DM on the neurocognitive functioning of affected individuals raise concerns about how the disease may influence executive functioning. Inhibition is a core component of executive functioning, and plays a vital role in self-regulation and the restriction of impulsive behaviors. Inhibition may thus play a vital role in the behavior management of people with T1DM. The aim of this study was to identify current gaps in existing knowledge regarding the relationship between T1DM, inhibition, and behavior management. This study employed a critical review design to analyze and synthesize the current scientific literature. Twelve studies were identified through an appraisal process, and the data extracted were thematically analyzed and integrated. The findings of this study indicate that a possible cycle arises between these three constructs, in which T1DM affects inhibition, inhibition affects behavior management, and poor behavior management affects inhibition. It is recommended that future research should focus more specifically on this relationship.

Effects of Interaction between SLC35F3 and Carbohydrate Intake on the Incidence of Metabolic Syndrome in Korean Middle-Aged Adults

Solute carrier family 35 member F3 (SLC35F3) mediates intracellular thiamine transport, which is crucial for carbohydrate metabolism as thiamine is required for key pathways such as glycolysis and the tricarboxylic acid cycle. This study aimed to investigate the impact of the interaction between SLC35F3 and dietary carbohydrate intake on the incidence of metabolic syndrome (MetS). The study included 3923 Korean adults over 40 years of age from the Korean Genome and Epidemiology Study. The association between dietary carbohydrate intake, SLC35F3 rs10910387 genotypes, and MetS incidence was studied using multivariable Cox proportional hazard models. Over an average of 8.5 years of follow-ups, we documented 1471 MetS cases. MetS incidence was 1.88 times greater in men with the TT genotype and the highest carbohydrate intake than in those with the CC genotype and lowest carbohydrate intake (Hazard Ratio (HR) 1.88, 95% confidence interval (CI) 1.03-3.41). MetS incidence were 2.22 and 2.53 times higher in women with the TT genotype and carbohydrate intake tertile 2 and 3, respectively, than those with the CC genotype and carbohydrate intake tertile 1 (HR 2.22, 95% CI 1.12-4.42; HR 2.53, 95% CI 1.38-4.61). In summary, we report a novel interaction between SLC35F3 rs10910387 genotypes and dietary carbohydrate intake on MetS in Koreans.

Effects of dietary vitamins on obesity-related metabolic parameters

Type 2 diabetes mellitus (T2DM) is one of the leading causes of death worldwide. Genetic factors, some underlying medical conditions, and obesity are risk factors of T2DM. Unlike other risk factors which are non-modifiable, obesity is preventable and usually treatable, and is largely contributed by lifestyle factors. Management of these lifestyle factors may curb the development of T2DM and reduces T2DM prevalence. Dietary vitamins have been recommended as a lifestyle modification intervention to support obesity treatment. Vitamins correlate negatively with body weight, body mass index and body composition. Some of the vitamins may also have anti-adipogenic, anti-inflammatory and antioxidant effects. However, results from pre-clinical and clinical studies of the effects of vitamins on obesity are inconsistent. A clear understanding of the effects of vitamins on obesity will help determine dietary intervention that is truly effective in preventing and treating obesity as well as obesity-related complications including T2DM. This article reviews existing evidences of the effects of vitamin supplementation on obesity and obesity-related metabolic status.

Association of thiamine administration and prognosis in critically ill patients with heart failure

Background: Thiamine deficiency is common in patients with heart failure, and thiamine supplement can benefit these patients. However, the association between thiamine administration and prognosis among critically ill patients with heart failure remains unclear. Thus, this study aims to prove the survival benefit of thiamine use in critically ill patients with heart failure. Methods: A retrospective cohort analysis was performed on the basis of the Medical Information Mart of Intensive Care-Ⅳ database. Critically ill patients with heart failure were divided into the thiamine and non-thiamine groups depending on whether they had received thiamine therapy or not during hospitalization. The association between thiamine supplement and in-hospital mortality was assessed by using the Kaplan-Meier (KM) method and Cox proportional hazard models. A 1:1 nearest propensity-score matching (PSM) and propensity score-based inverse probability of treatment weighting (IPW) were also performed to ensure the robustness of the findings. Results: A total of 7,021 patients were included in this study, with 685 and 6,336 in the thiamine and non-thiamine groups, respectively. The kaplan-meier survival curves indicated that the thiamine group had a lower in-hospital mortality than the none-thiamine group. After adjusting for various confounders, the Cox regression models showed significant beneficial effects of thiamine administration on in-hospital mortality among critically ill patients with heart failure with a hazard ratio of 0.78 (95% confidence interval: 0.67-0.89) in the fully adjusted model. propensity-score matching and probability of treatment weighting analyses also achieved consistent results. Conclusion: Thiamine supplement is associated with a decreased risk of in-hospital mortality in critically ill patients with heart failure who are admitted to the ICU. Further multicenter and well-designed randomized controlled trials with large sample sizes are necessary to validate this finding.

Wernicke's encephalopathy after acute pancreatitis with upper gastrointestinal obstruction: A case report and literature review

A 42-year-old female was admitted with upper abdominal pain. Imaging studies and laboratory tests were performed to consider acute lipogenic pancreatitis. After symptomatic treatment, her abdominal pain was significantly relieved. However, the patient was accompanied by upper gastrointestinal obstruction, which was gradually relieved after long-term fasting, gastrointestinal decompression, and fluid rehydration. The patient developed dizziness and ataxia, which worsened. Cranial magnetic resonance imaging (MRI) indicated patchy abnormal signal shadows in the bilateral thalami and dorsal brainstem and suggested metabolic encephalopathy. Wernicke's encephalopathy (WE) was the initial diagnosis of suspicion, adequate vitamin B1 was immediately replenished until the complete resolution of symptoms, and the patient made a rapid and dramatic recovery.

Nutritional Heart Disease and Cardiomyopathies: JACC Focus Seminar 4/4

This JACC Focus Seminar provides an overview of and highlights recently published research on cardiomyopathies and nutritional heart disease that have a higher prevalence in tropical regions. The development of tropical cardiomyopathies and nutritional cardiovascular disease (CVD) is complicated by high rates of poverty, fragmented health care systems, and suboptimal access to health care because of socioeconomic inequalities, leading to the fact that children, adolescents, and young adults are disproportionally affected. Such tropical cardiomyopathies and nutritional CVD that have not been prevalent in high-income countries in the past decades are now reemerging. When treating migrants or refugees, it is important for attending physicians to consider the burden of endemic diseases in the countries of origin and the likelihood that such patients might be affected. In this review, the authors propose an approach for adequate diagnostic work-up leading to appropriate care for those with suspected or confirmed tropical cardiomyopathies and nutritional CVD.

Untargeted Metabolomics Reveals Antidepressant Effects in a Marine Photosynthetic Organism: The Diatom Phaeodactylum tricornutum as a Case Study

The increased use of antidepressants, along with their increased occurrence in aquatic environments, is of concern for marine organisms. Although these pharmaceutical compounds have been shown to negatively affect marine diatoms, their mode of action in these non-target, single-cell phototrophic organisms is yet unknown. Using a Fourier-transform ion cyclotron-resonance mass spectrometer (FT-ICR-MS) we evaluated the effects of fluoxetine in the metabolomics of the model diatom Phaeodactylum tricornutum, as well as the potential use of the identified metabolites as exposure biomarkers. Diatom growth was severely impaired after fluoxetine exposure, particularly in the highest dose tested, along with a down-regulation of photosynthetic and carbohydrate metabolisms. Notably, several mechanisms that are normally down-regulated by fluoxetine in mammal organisms were also down-regulated in diatoms (e.g., glycerolipid metabolism, phosphatidylinositol signalling pathway, vitamin metabolism, terpenoid backbone biosynthesis and serotonin remobilization metabolism). Additionally, the present work also identified a set of potential biomarkers of fluoxetine exposure that were up-regulated with increasing fluoxetine exposure concentration and are of high metabolic significance following the disclosed mode of action, reinforcing the use of metabolomics approaches in ecotoxicology.

Influence of biotin intervention on glycemic control and lipid profile in patients with type 2 diabetes mellitus: A systematic review and meta-analysis

Background

Biotin is a water-soluble vitamin acting as a covalently bound coenzyme in regulating energy production. Previous studies have reported that biotin supplementation may influence blood glucose and lipid level in patients with type 2 diabetes mellitus (T2DM).

Methods

We searched Pubmed, Embase, and Cochrane library databases up to 8th August 2022 for studies examining the effects of biotin supplementation in T2DM patients. Pooled effects were measured by weighted mean differences (WMDs) with 95% confidence intervals (CI) using random effects models. Inter-study heterogeneity was assessed and quantified.

Results

A total of five random controlled trials (RCT), involving 445 participants were included. It was suggested that biotin supplementation for 28 to 90 days significantly decreased the level of fasting blood glucose (FBG) (MD: -1.21 mmol/L, 95% CI: -2.73 to 0.31), total cholesterol (TC) (MD: -0.22 mmol/L, 95% CI: -0.25 to -0.19) and triglycerides (TG) (MD: -0.59 mmol/L, 95% CI: -1.21 to 0.03). No significant beneficial effects were observed on insulin (MD: 1.88 pmol/L 95% CI: -13.44 to 17.21). Evidence for the impact of biotin supplementation on the levels of glycated hemoglobin (HbA1c), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and very low-density lipoprotein cholesterol (VLDL-C) was limited to draw conclusion.

Conclusions

Biotin supplementation may decrease FBG, TC and TG levels. However, its influence on insulin is not significant and further studies on the effects of biotin on HbA1c, LDL-C, HDL-C and VLDL-C are expected.

The role of pancreas to improve hyperglycemia in STZ-induced diabetic rats by thiamine disulfide

Background

The present study investigated the effect of thiamine disulfide (TD) on the pancreas in terms of hyperglycemia improvement and insulin sensitivity increase in diabetic male rats. We also aimed to study the function of Pdx1 (pancreatic and duodenal homeobox 1) and Glut2 (glucose transporter 2) genes in pancreatic tissue.

Methods

Type 1 diabetes was induced through injection of 60 mg/kg streptozotocin (STZ). The diabetic rats were divided into four groups, namely diabetic control (DC), diabetic treated with thiamine disulfide (D-TD), diabetic treated with insulin (D-insulin), and diabetic treated with TD and insulin (D-insulin+TD). The non-diabetic (NDC) and diabetic groups received a normal diet (14 weeks). Blood glucose level and body weight were measured weekly; insulin tolerance test (ITT) and glucagon tolerance test (GTT) were performed in the last month of the study. The level of serum insulin and glucagon were measured monthly and a hyperglycemic clamp (Insulin Infusion rate (IIR)) was done for all the groups. Pancreas tissue was isolated so that Pdx1and Glut2 genes expression could be measured.

Results

We observed that TD therapy decreased blood glucose level, ITT, and serum glucagon levels in comparison with those of the DC group; it also increased serum insulin levels, IIR, and expression of Pdx1 and Glut2 genes in comparison with those of the DC group.

Conclusion

Administration of TD could improve hyperglycemia in type 1 diabetic animals through improved pancreas function. Therefore, not only does TD have a significant effect on controlling and reducing hyperglycemia in diabetes, but it also has the potential to decrease the dose of insulin administration.

Thiamine Is a Natural Peroxisome Proliferator–Activated Receptor Gamma (PPAR-γ) Activator

Background:

There has been increasing evidence for the correlation between thiamine deficiency and type 2 diabetes (T2D). T2D is a condition in which an individual’s insulin sensitivity is highly compromised. Peroxisome proliferator–activated receptor gamma (PPAR-γ) is a ligand-activated transcription factor etiologically relevant to T2D. We hypothesized that thiamine could be a PPAR-γ ligand and thus activate PPAR-γ and ameliorate T2D.

Objective:

This study aims to establish thiamine as a PPAR-γ ligand via molecular docking and dynamics simulations (MDS) and thiamine’s ability to induce adipogenesis, upregulating PPAR-γ and AP-2 genes using in vitro assays.

Methods:

Thiamine/PPAR-γ binding was studied using Schrödinger’s Glide. The bound complex was simulated in the OPLS 2005 force field using Desmond. 3T3-L1 preadipocyte cells were differentiated in the presence of thiamine and rosiglitazone and stained with Oil Red O. Nuclear protein from the differentiated cells was used to study the binding of the PPAR-γ response element (PPRE) using an ELISA-based assay. mRNA from differentiated cells was used to study the expression of genes using quantitative RT-PCR.

Results:

In silico docking shows that thiamine binds with PPAR-γ. MDS indicate that the interactions between thiamine and PPAR-γ are stable over a significant period. Thiamine induces the differentiation of 3T3-L1 preadipocytes in a dose-dependent manner and enhances the PPRE-binding activity of PPAR-γ. Thiamine treatment significantly increases the mRNA levels of PPAR-γ and AP-2 genes.

Conclusion:

Our results show that thiamine is a PPAR-γ ligand. Animal studies and clinical trials are required to corroborate the results obtained.

Synthesis, physico-chemical properties and effect of adenosine thiamine triphosphate on vitamin B1 metabolism in the liver of alloxan diabetic rats

BACKGROUND

Adenosine thiamine triphosphate (AThTP) is a nucleotide discovered in bacteria and some other living organisms more than a decade ago. No biochemical function for AThTP has been established yet, however, experimental data available indicate its possible involvement in metabolic regulation or cell signaling. Metabolism of AThTP in mammals, as well as the feasibility of its pharmacological application, is essentially unstudied.

METHODS

Preparative low-pressure chromatography was employed to purify chemically synthesized AThTP with its further analysis by mass spectrometry, HPLC, UV and fluorescence spectroscopy. Enzyme activity assays along with HPLC were used to examine the effects of AThTP and thiamine on vitamin B₁ metabolism in the liver of alloxan-induced diabetic rats.

RESULTS

An improved procedure for AThTP synthesis and purification is elaborated. Solution stability, optical spectral properties and the molar absorption coefficient for AThTP were determined. The levels of thiamine compounds were found to be increased in the liver of diabetic rats. Neither AThTP nor thiamine treatment affected hepatic vitamin B₁ metabolism. Fasting blood glucose concentration was also unchangeable after AThTP or thiamine administration.

GENERAL SIGNIFICANCE

Contrast to the widespread view about thiamine deficiency in diabetes, our results clearly shows an adaptive increase in the level of B₁ vitamers in the liver of alloxan diabetic rats with no further rising after AThTP or thiamine treatment at a moderate dose. Neither AThTP nor thiamine is effective in glycaemic control. These findings are to be considered in future studies dealing with thiamine or its analogues application to correct metabolic disturbances in diabetes.

Interrelationship between micronutrients and cardiovascular structure and function in type 2 diabetes

Micronutrients are important for normal cardiovascular function. They may play a role in the increased risk of cardiovascular disease observed in people with type 2 diabetes (T2D) and T2D-related heart failure. The aims of this study were to (1) examine micronutrient status in people with T2D v. healthy controls; (2) assess any changes following a nutritionally complete meal replacement plan (MRP) compared with routine care; (3) determine if any changes were associated with changes in cardiovascular structure/function. This was a secondary analysis of data from a prospective, randomised, open-label, blinded end-point trial of people with T2D, with a nested case-control [NCT02590822]. Anthropometrics, cardiac resonance imaging and fasting blood samples (to quantify vitamins B1, B6, B12, D and C; and iron and ferritin) were collected at baseline and 12 weeks following the MRP or routine care. Comparative data in healthy controls were collected at baseline. A total of eighty-three people with T2D and thirty-six healthy controls were compared at baseline; all had micronutrient status within reference ranges. Vitamin B1 was higher (148⋅9 v. 131⋅7; P 0⋅01) and B6 lower (37⋅3 v. 52⋅9; P 0⋅01) in T2D v. controls. All thirty participants randomised to routine care and twenty-four to the MRP completed the study. There was an increase in vitamins B1, B6, D and C following the MRP, which were not associated with changes in cardiovascular structure/function. In conclusion, changes in micronutrient status following the MRP were not independently associated with improvements in cardiovascular structure/function in people with T2D.

Thiamine modulates intestinal morphological structure and microbiota under subacute ruminal acidosis induced by a high-concentrate diet in Saanen goats

Ruminant animals are generally fed with starch-rich grain as the main energy source, and the incidence of metabolic diseases such as subacute ruminal acidosis (SARA) is high due to the intensive farming. Thiamin has been reported to alleviate SARA caused by high-concentrate diets, but the exact mechanism is not well understood. The goal of this study was to examine the role of thiamine in intestinal inflammation and microbiota caused by high-concentrate diets. The SARA model was induced by low neutral detergent fibre/starch ration to study the effects of thiamine on intestinal tissue structure and microbiota. 18 mid-lactation (148 ± 3 d in milk; milk yield = 0.71 ± 0.0300 kg/d) Saanen goats (BW = 36.5 ± 1.99 kg; body condition score = 2.73 ± 0.16, where 1 = emaciated and 6 = obese) in parities 1 or 2 were selected. The goats were randomly divided into three groups with six replicates: (1) control diet (C; concentrate:forage 30:70), (2) high-concentrate diet (H; concentrate:forage 70:30), and (3) high-concentrate diet with 200 mg of thiamine/kg of DM intake (H + T;concentrate:forage 70:30). The experimental period was lasted for 56 d. The small and large intestine, expression of inflammatory factor genes, tight junction protein genes, total antioxidant capacity, and intestinal microbiota were measured. The results showed that SARA was observed in treatment H, whereas rumen fluid pH was improved in treatment H + T. Treatment H + T also significantly repaired the intestinal tissue structure damaged by SARA, improved the total antioxidant capacity of the small intestinal mucosa, reduced mRNA expression of inflammatory factors in the small intestine tissue, and increased the mRNA expression of tight junction genes in small intestine tissue. The high-concentrate diet reduced the diversity of intestinal microbiota. When thiamine is added to the high-concentrate diet, the relative abundance of intestinal Firmicutes and beneficial bacteria represented by Lactobacilli were upregulated, and the relative abundance of Proteus, a marker of intestinal dysbacteriosis, returned to normal. In conclusion, thiamine supplementation could alleviate the damage to the intestinal tissue structure and microbial environment caused by SARA condition in dairy goats fed a high-concentrate diet.

Hiding in Plain Sight: Modern Thiamine Deficiency

Thiamine or vitamin B1 is an essential, water-soluble vitamin required for mitochondrial energetics—the production of adenosine triphosphate (ATP). It is a critical and rate-limiting cofactor to multiple enzymes involved in this process, including those at the entry points and at critical junctures for the glucose, fatty acid, and amino acid pathways. It has a very short half-life, limited storage capacity, and is susceptible to degradation and depletion by a number of products that epitomize modern life, including environmental and pharmaceutical chemicals. The RDA for thiamine is 1.1–1.2 mg for adult females and males, respectively. With an average diet, even a poor one, it is not difficult to meet that daily requirement, and yet, measurable thiamine deficiency has been observed across multiple patient populations with incidence rates ranging from 20% to over 90% depending upon the study. This suggests that the RDA requirement may be insufficient to meet the demands of modern living. Inasmuch as thiamine deficiency syndromes pose great risk of chronic morbidity, and if left untreated, mortality, a more comprehensive understanding thiamine chemistry, relative to energy production, modern living, and disease, may prove useful.

Alpha-lipoic acid and vitamin B complex slow down the changes in mice diabetic cardiomyopathy

Aim: The aim of our study was to assess histologically and by cardiac ultrasound the effects of alpha-lipoic acid (ALA) and vitamin B complex, as pathogenic therapies, in diabetic cardiomyopathy (DCM) in mice. Materials and Methods: We performed an experimental animal study, in which we analyzed from a structural and functional point of view the changes produced in DCM. To produce DCM, we induced diabetes mellitus (DM) in C57BL/6 mice by intraperitoneal injection of a single 150 mg/kg body weight dose of streptozotocin (STZ). We formed a sham group (animals without DM), a control group (animals with DM but without treatment, DM_Control) and a group of animals with DM that were treated with ALA and vitamin B complex (DM_Treated). Results: At six weeks after STZ administration, there was no decrease in left ventricular ejection fraction (LVEF) in the sham group, while in the control group there was a significant decrease in LVEF, about 43.75±3.37%, compared to the group that received treatment with ALA and vitamin B complex, in which LVEF decreased to 49.6±5.02% (p=0.0432). Also, the degree of interstitial myocardial fibrosis was higher in animals with DM compared to animals without DM, but the applied therapeutic protocol considerably improved the accumulation of interstitial collagen. The same observation was maintained regarding the evaluation of polysaccharide deposits. Conclusions: We can say that the administration of ALA and vitamin B complex in mice with STZ-induced DM, improves the degree of myocardial fibrosis, the accumulation of polysaccharides, and prevents severe deterioration of systolic and diastolic function of the heart.

Age-related changes in the parameters of carbohydrate metabolism and supply of vitamins B1, B2 in residents of two northern regions

A great deal of research was being done in studying of the age-related characteristics of carbohydrate metabolism and the provision of vitamins B1, B2 among the population of the Subarctic (SR) and Arctic (AR) regions, differing in the extreme natural and climatic-geographic living conditions. The surveyed population was divided into five age groups: 16-21, 22-35, 36-45, 46-60 and 61-74 years old. The parameters of carbohydrate metabolism (glucose, lactate, pyruvate) were determined in the blood serum, the content of thiamine (thiamin diphosphate effect) and riboflavin - in hemolysates, and the values of the lactate/pyruvate ratio (Lac/Pyr) were calculated. Statistical data processing was performed by nonparametric methods. An increase in glucose levels was found in persons of older age groups. Age-related fluctuations of metabolites of carbohydrate metabolism were manifested by a lower content of lactate and the value of the Lac/Pyr ratio in persons aged 16-21 years. Regardless of the age and region of the survey, there were revealed high lactate concentrations, Lac/Pyr values and reduced pyruvate levels, as well as low glucose levels in group aged 16-21 year in AR. For vitamins B1, B2, no pronounced age-related changes were observed, while the content of riboflavin was higher in persons of SR. Moderate hypovitaminosis of thiamin was detected in 13-20,1% and 6,1-22,7% of cases in SR and AR, pronounced - 8,3-11,6% and 4,6-23,5%, respectively, vitamin B2 deficiency was noted in 19,4-23,9% of persons in the AR and in 33,8-42,9% of persons in the AR. Vitamins in both regions at different age periods contributed to the formation of levels of indicators of carbohydrate metabolism: glucose and pyruvate in SR, lactate in AR.

The role of biofactors in the prevention and treatment of age-related diseases

The present demographic changes toward an aging society caused a rise in the number of senior citizens and the incidence and burden of age-related diseases (such as cardiovascular diseases [CVD], cancer, nonalcoholic fatty liver disease [NAFLD], diabetes mellitus, and dementia), of which nearly half is attributable to the population ≥60 years of age. Deficiencies in individual nutrients have been associated with increased risks for age-related diseases and high intakes and/or blood concentrations with risk reduction. Nutrition in general and the dietary intake of essential and nonessential biofactors is a major determinant of human health, the risk to develop age-related diseases, and ultimately of mortality in the older population. These biofactors can be a cost-effective strategy to prevent or, in some cases, even treat age-related diseases. Examples reviewed herein include omega-3 fatty acids and dietary fiber for the prevention of CVD, α-tocopherol (vitamin E) for the treatment of biopsy-proven nonalcoholic steatohepatitis, vitamin D for the prevention of neurodegenerative diseases, thiamine and α-lipoic acid for the treatment of diabetic neuropathy, and the role of folate in cancer epigenetics. This list of potentially helpful biofactors in the prevention and treatment of age-related diseases, however, is not exhaustive and many more examples exist. Furthermore, since there is currently no generally accepted definition of the term biofactors, we here propose a definition that, when adopted by scientists, will enable a harmonization and consistent use of the term in the scientific literature.

A Pilot Metabolomic Study on Myocardial Injury Caused by Chronic Alcohol Consumption-Alcoholic Cardiomyopathy

Chronic alcohol consumption leads to myocardial injury, ventricle dilation, and cardiac dysfunction, which is defined as alcoholic cardiomyopathy (ACM). To explore the induced myocardial injury and underlying mechanism of ACM, the Liber-DeCarli liquid diet was used to establish an animal model of ACM and histopathology, echocardiography, molecular biology, and metabolomics were employed. Hematoxylin-eosin and Masson's trichrome staining revealed disordered myocardial structure and local fibrosis in the ACM group. Echocardiography revealed thinning wall and dilation of the left ventricle and decreased cardiac function in the ACM group, with increased serum levels of brain natriuretic peptide (BNP) and expression of myocardial BNP mRNA measured through enzyme-linked immunosorbent assay and real-time quantitative polymerase chain reaction (PCR), respectively. Through metabolomic analysis of myocardium specimens, 297 differentially expressed metabolites were identified which were involved in KEGG pathways related to the biosynthesis of unsaturated fatty acids, vitamin digestion and absorption, oxidative phosphorylation, pentose phosphate, and purine and pyrimidine metabolism. The present study demonstrated chronic alcohol consumption caused disordered cardiomyocyte structure, thinning and dilation of the left ventricle, and decreased cardiac function. Metabolomic analysis of myocardium specimens and KEGG enrichment analysis further demonstrated that several differentially expressed metabolites and pathways were involved in the ACM group, which suggests potential causes of myocardial injury due to chronic alcohol exposure and provides insight for further research elucidating the underlying mechanisms of ACM.

Gut microbiota compositions and metabolic functions in type 2 diabetes differ with glycemic durability to metformin monotherapy

AIMS

The metabolic derangements in type 2 diabetes have been attributed to compositional changes in the gut microbiota. Metformin, the first-line treatment for type 2 diabetes, has been found to modulate the gut microbiota. However, no literature has reported the associations between the composition of the gut microbiota and glycemic durability to metformin monotherapy.

METHODS

A total of 375 patients with type 2 diabetes were recruited, among which 14 and 11 patients were eligible as the metformin durable group and nondurable group, respectively. Fecal samples were collected to analyze the gut microbiota by Illumina sequencing of the 16S rRNA gene, and PICRUSt2 was adopted to infer microbial functional differences.

RESULTS

Although the two groups had similar biochemical profiles and microbial metabolites, the pattern of microbiota clustering was different. The intra-group diversity was significantly reduced in the durable group. For the microbial metabolic pathways, the biosynthesis of thiamine and lipopolysaccharide was dominant in the durable group.

CONCLUSIONS

There were different compositions of gut microbiota with unique microbial metabolic pathways between type 2 diabetes with and without glycemic durability to metformin monotherapy. Microbial salvage by increasing thiamine biosynthesis might be beneficial for the metformin durable group to maintain optimal glycemic control.

Kale Attenuates Inflammation and Modulates Gut Microbial Composition and Function in C57BL/6J Mice with Diet-Induced Obesity

Kale (Brassica oleracea var. acephala) is a vegetable common in most cultures but is less studied as a functional food compared to other cruciferous vegetables, such as broccoli. We investigated the effect of supplementing a high-fat diet (HFD) with kale (HFKV) in C57BL/6J mice. We particularly explored its role in metabolic parameters, gut bacterial composition and diversity using 16S rRNA sequencing, systematically compared changes under each phylum and predicted the functional potential of the altered bacterial community using PICRUSt2. Like other cruciferous vegetables, kale attenuated HFD-induced inflammation. In addition, kale modulated HFD-induced changes in cecal microbiota composition. The HFD lowered bacterial diversity, increased the Firmicutes: Bacteroidetes (F/B) ratio and altered composition. Specifically, it lowered Actinobacteria and Bacteroidetes (Bacteroidia, Rikenellaceae and Prevotellaceae) but increased Firmicutes (mainly class Bacilli). Kale supplementation lowered the F/B ratio, increased both alpha and beta diversity and reduced class Bacilli and Erysipelotrichi but had no effect on Clostridia. Within Actinobacteria, HFKV particularly increased Coriobacteriales/Coriobacteriaceae about four-fold compared to the HFD (p < 0.05). Among Bacteroidia, HFKV increased the species Bacteroides thetaiotaomicron by over two-fold (p = 0.05) compared to the HFD. This species produces plant polysaccharide digesting enzymes. Compared to the HFD, kale supplementation enhanced several bacterial metabolic functions, including glycan degradation, thiamine metabolism and xenobiotic metabolism. Our findings provide evidence that kale is a functional food that modulates the microbiota and changes in inflammation phenotype.

The Inferior Colliculus in Alcoholism and Beyond

Post-mortem neuropathological and in vivo neuroimaging methods have demonstrated the vulnerability of the inferior colliculus to the sequelae of thiamine deficiency as occurs in Wernicke-Korsakoff Syndrome (WKS). A rich literature in animal models ranging from mice to monkeys-including our neuroimaging studies in rats-has shown involvement of the inferior colliculi in the neural response to thiamine depletion, frequently accomplished with pyrithiamine, an inhibitor of thiamine metabolism. In uncomplicated alcoholism (i.e., absent diagnosable neurological concomitants), the literature citing involvement of the inferior colliculus is scarce, has nearly all been accomplished in preclinical models, and is predominately discussed in the context of ethanol withdrawal. Our recent work using novel, voxel-based analysis of structural Magnetic Resonance Imaging (MRI) has demonstrated significant, persistent shrinkage of the inferior colliculus using acute and chronic ethanol exposure paradigms in two strains of rats. We speculate that these consistent findings should be considered from the perspective of the inferior colliculi having a relatively high CNS metabolic rate. As such, they are especially vulnerable to hypoxic injury and may be provide a common anatomical link among a variety of disparate insults. An argument will be made that the inferior colliculi have functions, possibly related to auditory gating, necessary for awareness of the external environment. Multimodal imaging including diffusion methods to provide more accurate in vivo visualization and quantification of the inferior colliculi may clarify the roles of brain stem nuclei such as the inferior colliculi in alcoholism and other neuropathologies marked by altered metabolism.

The Relevance of Thiamine Evaluation in a Practical Setting

Thiamine is a crucial cofactor involved in the maintenance of carbohydrate metabolism and participates in multiple cellular metabolic processes. Although thiamine can be obtained from various food sources, some common food groups are deficient in thiamine, and it can be denatured by high temperature and pH. Additionally, different drugs can alter thiamine metabolism. In addition, the half-life of thiamine in the body is between 1 and 3 weeks. All these factors could provide an explanation for the relatively short period needed to develop thiamine deficiency and observe the consequent clinical symptoms. Thiamine deficiency could lead to neurological and cardiological problems. These clinical conditions could be severe or even fatal. Marginal deficiency too may promote weaker symptoms that might be overlooked. Patients undergoing upper gastrointestinal or pancreatic surgery could have or develop thiamine deficiency for many different reasons. To achieve the best outcome for these patients, we strongly recommend the execution of both an adequate preoperative nutritional assessment, which includes thiamine evaluation, and a close nutritional follow up to avoid a nutrient deficit in the postoperative period.

Blood thiamine pyrophosphate concentration and its correlation with the stage of diabetic retinopathy

PURPOSE

To assess the possible relationship between blood thiamine pyrophosphate (TPP) concentration and stage of diabetic retinopathy (DR).

METHODS

This comparative cross-sectional study included 80 patients with type 2 diabetes mellitus (T2DM) and 20 age- and gender-matched healthy controls. Diabetic patients were subclassified into four groups each consisting of 20 subjects: no DR, mild-moderate non-proliferative DR (mild-moderate NPDR), severe NPDR, and proliferative DR (PDR). Blood TPP concentration was assessed with high-performance liquid chromatography (HPLC) assay and was correlated with the stage of DR.

RESULTS

Mean blood TPP concentration was 80.2 ± 14.8 nmol/L in control group. It was, respectively, 69.85 ± 18.1, 64.95 ± 13.4, 61.9 ± 13.4 and 60.75 ± 14.3 nmol/L in no DR, mild-moderate NPDR, severe NPDR and PDR groups. For mild-moderate NPDR, severe NPDR and PDR groups, TPP concentrations were significantly lower compared with controls (p: 0.014, 0.002, 0.001, respectively). Mean TPP concentration for NPDR patients was higher than for PDR patients, but the difference was not significant (p: 0.478). ANOVA revealed a significant difference between TPP concentrations of groups (p: 0.001). Mean TPP concentration decreased with the stage of DR, and number of patients with thiamine deficiency increased gradually with the stage of DR. A negative correlation was found between the TPP level and occurrence of DR (p: 0.000).

CONCLUSION

The results suggest that lower blood TPP concentrations were associated with higher risk of DR. Thiamine might play an important role in the pathophysiology and progression of DR. Thiamine and its derivatives might represent an approach to the prevention and/or treatment of early DR.

Thiamine Level in Type I and Type II Diabetes Mellitus Patients: A Comparative Study Focusing on Hematological and Biochemical Evaluations

Objective

Diabetes has been found to be associated with low levels of thiamine stores in the body, as thiamine directly affects carbohydrate metabolism. Amplified renal clearance of thiamine has been found in both type I and type II diabetic patients. It has been shown that high-dose thiamine therapy may have a therapeutic effect on early-stage diabetic nephropathy. The aim of this study was to evaluate various biochemical parameters and serum thiamine levels in type I and type II diabetic patients and compare them with a healthy control group.

Methods

A case-control study was carried out in the diabetic out-patient multi-centers in Karachi. A total of 90 participants were selected by using a non-probability convenient sampling technique and divided into three groups, each with 30 subjects. Group A included healthy non-diabetic subjects, while group B included subjects with type I diabetes mellitus (DM), and group C included subjects with type II DM. After receiving informed consent, blood samples were collected from all the participants for hematological and biochemical evaluation. The duration of the study was eight months.

Results

The study results revealed that the patients with type II DM had significantly higher mean fasting blood sugar (FBS), random blood sugar (RBS), and hemoglobin A1c (HbA1c) levels than those with type I DM or the control group (p<0.001 for all). Furthermore, the patients with type I or II DM had significantly higher mean levels of triglyceride (p<0.001) and total cholesterol (0.013) while significantly lower mean levels of high-density lipoprotein (HDL) (p=0.014) than controls. The study results further revealed that the patients with type I or II DM had significantly lower serum thiamine levels than controls (14.89±4.82 and 7.35±1.90 vs. 69.56±12.75, p<0.001).

Conclusion

The study results revealed that FBS, RBS, HbA1c, triglyceride, and total cholesterol levels were significantly higher in both type I and type II diabetes patients compared to controls. Furthermore, HDL and serum thiamine levels were found to be significantly lower in both type I and type II diabetic patients than in controls.

Prevalence of Low Plasma Vitamin B1 in the Stroke Population Admitted to Acute Inpatient Rehabilitation

OBJECTIVE

To determine the prevalence of vitamin B1 (VitB1) deficiency in the stroke population admitted to acute inpatient rehabilitation.

DESIGN

Retrospective cohort study.

SETTING

Acute inpatient rehabilitation facility at an academic medical center.

PARTICIPANTS

119 consecutive stroke patients admitted to stroke service from 1 January 2018 to 31 December 2018.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Plasma VitB1 level.

RESULTS

There were 17 patients (14%; 95% CI 9-22%) with low VitB1 with a range of 2-3 nmol/L, an additional 58 (49%; CI 40-58%) patients had normal low VitB1 with a range of 4-9 nmol/L, twenty-five patients (21%; CI 15-29%) had normal high VitB1 with a range of 10-15 nmol/L, and nineteen patients (16%; CI 10-24%) had high VitB1 with a range of 16-43 nmol/L.

CONCLUSIONS

In this cohort of patients admitted to the stroke service at an acute rehabilitation facility, there is evidence of thiamine deficiency. Moreover, the data suggest that there is inadequate acute intake of VitB1. Given the role of thiamine deficiency in neurologic function, further study of the role of thiamine optimization in the acute stroke rehabilitation population is warranted.

Thiamine pyrophosphate diminishes nitric oxide synthesis in endothelial cells

Although thiamine pyrophosphate (TPP) is considered a protective agent for endothelial cells, it is still unknown if this is associated with nitric oxide (NO) synthesis. Our aim was to evaluate the synthesis of NO in endothelial cells incubated with TPP and high glucose concentrations. Endothelial cells from the umbilical cord vein from newborns (n = 20), were incubated with 5, 15 or 30 mmol/L glucose, in absence or presence of 0.625 mg/ml of TPP. Our results showed a significant increase in cell proliferation (> 40%; P < 0.05), and cell viability (> 90%; P < 0.001) after 48 h in endothelial cells cultured with glucose plus TPP. Likewise, in the presence of glucose and TPP an important rise in the consumption of glucose by the endothelial cells was observed after 24 h (> 7%; P < 0.001) and 48 h (> 10%; P < 0.05). Additionally, the levels of lactate after incubation with glucose and TPP showed only slight variations after 48 h (P < 0.05). However, these changes were clearly different from those observed in the absence of TPP. Interestingly, we found that the changes mentioned were linked with reduced levels of nitrites both at 24 h (< 171 pmol/μg protein; P < 0.001), and 48 h (< 250 pmol/μg protein; P < 0.05), which was associated with a reduced expression of mRNA of eNOS in endothelial cells incubated with TPP and high glucose. In conclusion, the presence of TPP regulates the consumption of glucose and the synthesis of NO, which would explain its protective effect in the endothelium of diabetic patients.

Thiamine for Prevention of Postoperative Delirium in Patients Undergoing Gastrointestinal Surgery: A Randomized Clinical Trial

Objective:

Postoperative delirium is a common complication after gastrointestinal surgery that is associated with adverse outcomes. Thiamine is an essential cofactor for the glycolysis, oxidative metabolism, production of neurotransmitters in the crebs cycle. In this study, efficacy of thiamine was assessed as a preventive strategy of delirium in patients undergoing gastrointestinal surgery.

Methods:

In this randomized clinical trial, 96 adult patients admitted to the intensive care unit (ICU) following gastrointestinal surgery were included. Patients were allocated to receive either 200 mg intravenous thiamine daily or an equal volume of 0.9% saline for 3 days. Delirium was evaluated twice daily based on the confusion assessment method-ICU. The incidence of postoperative delirium was considered as the primary outcome, and total analgesic use and ventilation days has been defined as secondary outcomes of the study.

Findings:

The incidence rate of delirium was significantly lower in the thiamine group than the placebo group on the first day (8.3% vs. 25%; Odds ratio: 0.27 [95% confidence interval (CI): 0.08–0.92]; P= 0.026) and on the second day (4.2% vs. 20.8%; or: 0.16 [95% CI: 0.03–0.81]; P= 0.014). No adverse effect related to thiamine was detected during the study course.

Conclusion:

Study results suggest that thiamine is a safe option for the prevention of postoperative delirium in patients after gastrointestinal surgery.

One-carbon metabolites, B vitamins and associations with systemic inflammation and angiogenesis biomarkers among colorectal cancer patients: results from the ColoCare Study

B vitamins involved in one-carbon metabolism have been implicated in the development of inflammation- and angiogenesis-related chronic diseases, such as colorectal cancer (CRC). Yet, the role of one-carbon metabolism in inflammation and angiogenesis among CRC patients remains unclear. The objective of this study was to investigate associations of components of one-carbon metabolism with inflammation and angiogenesis biomarkers among newly diagnosed CRC patients (n 238) in the prospective ColoCare Study, Heidelberg. We cross-sectionally analysed associations between twelve B vitamins and one-carbon metabolites and ten inflammation and angiogenesis biomarkers from pre-surgery serum samples using multivariable linear regression models. We further explored associations among novel biomarkers in these pathways with Spearman partial correlation analyses. We hypothesised that pyridoxal-5'-phosphate (PLP) is inversely associated with inflammatory biomarkers. We observed that PLP was inversely associated with C-reactive protein (CRP) (r -0·33, Plinear < 0·0001), serum amyloid A (SAA) (r -0·23, Plinear = 0·003), IL-6 (r -0·39, Plinear < 0·0001), IL-8 (r -0·20, Plinear = 0·02) and TNFα (r -0·12, Plinear = 0·045). Similar findings were observed for 5-methyl-tetrahydrofolate and CRP (r -0·14), SAA (r -0·14) and TNFα (r -0·15) among CRC patients. Folate catabolite acetyl-para-aminobenzoylglutamic acid (pABG) was positively correlated with IL-6 (r 0·27, Plinear < 0·0001), and pABG was positively correlated with IL-8 (r 0·21, Plinear < 0·0001), indicating higher folate utilisation during inflammation. Our data support the hypothesis of inverse associations between PLP and inflammatory biomarkers among CRC patients. A better understanding of the role and inter-relation of PLP and other one-carbon metabolites with inflammatory processes among colorectal carcinogenesis and prognosis could identify targets for future dietary guidance for CRC patients.

Thiamine (vitamin B1) in septic shock: a targeted therapy

Thiamine (vitamin B1) is a water-soluble vitamin essential for human health. Thiamine deficiency is causal and/or contributory in a number of debilitating diseases including beri-beri, the Wernicke-Korsakoff syndrome, optic neuropathy, and others. While thiamine deficiency is relatively rare in developed nations as a result of dietary supplementation, thiamine deficiency is more common in nutritionally compromised populations. Thiamine pyrophosphate, a thiamine derivative, is essential to the citric acid cycle and thiamine deficiency can result in impaired aerobic respiration and cellular energy production. Thiamine also plays an important role in the pentose phosphate pathway and other key metabolic processes. Although thiamine deficiency is a known cause of lactic acidosis, it has been recently evaluated as a potential contributor to refractory lactic acidosis and organ injury in septic shock and other shock states. In this article, we review the epidemiology of thiamine deficiency in septic shock and the existing evidence base supporting thiamine supplementation. We conclude that specific sepsis phenotypes may stand to benefit the most from thiamine supplementation, and efforts might be made to identify and supplement these patients early in their hospital course.

Mechanisms of Non-coenzyme Action of Thiamine: Protein Targets and Medical Significance

Thiamine (vitamin B1) is a precursor of the well-known coenzyme of central metabolic pathways thiamine diphosphate (ThDP). Highly intense glucose oxidation in the brain requires ThDP-dependent enzymes, which determines the critical significance of thiamine for neuronal functions. However, thiamine can also act through the non-coenzyme mechanisms. The well-known facilitation of acetylcholinergic neurotransmission upon the thiamine and acetylcholine co-release into the synaptic cleft has been supported by the discovery of thiamine triphosphate (ThTP)-dependent phosphorylation of the acetylcholine receptor-associated protein rapsyn, and thiamine interaction with the TAS2R1 receptor, resulting in the activation of synaptic ion currents. The non-coenzyme regulatory binding of thiamine compounds has been demonstrated for the transcriptional regulator p53, poly(ADP-ribose) polymerase, prion protein PRNP, and a number of key metabolic enzymes that do not use ThDP as a coenzyme. The accumulated data indicate that the molecular mechanisms of the neurotropic action of thiamine are far broader than it has been originally believed, and closely linked to the metabolism of thiamine and its derivatives in animals. The significance of this topic has been illustrated by the recently established competition between thiamine and the antidiabetic drug metformin for common transporters, which can be the reason for the thiamine deficiency underlying metformin side effects. Here, we also discuss the medical implications of the research on thiamine, including the role of thiaminases in thiamine reutilization and biosynthesis of thiamine antagonists; molecular mechanisms of action of natural and synthetic thiamine antagonists, and biotransformation of pharmacological forms of thiamine. Given the wide medical application of thiamine and its synthetic forms, these aspects are of high importance for medicine and pharmacology, including the therapy of neurodegenerative diseases.

The Catalytic Mechanism of Human Transketolase

We have computationally determined the catalytic mechanism of human transketolase (hTK) using a cluster model approach and density functional theory calculations. We were able to determine all the relevant structures, bringing solid evidences to the proposed experimental mechanism, and to add important detail to the structure of the transition states and the energy profile associated with catalysis. Furthermore, we have established the existence of a crucial intermediate of the catalytic cycle, in agreement with experiments. The calculated data brought new insights to hTK's catalytic mechanism, providing free-energy values for the chemical reaction, as well as adding atomistic detail to the experimental mechanism.

B Vitamins in the nervous system: Current knowledge of the biochemical modes of action and synergies of thiamine, pyridoxine, and cobalamin

Background

Neurotropic B vitamins play crucial roles as coenzymes and beyond in the nervous system. Particularly vitamin B1 (thiamine), B6 (pyridoxine), and B12 (cobalamin) contribute essentially to the maintenance of a healthy nervous system. Their importance is highlighted by many neurological diseases related to deficiencies in one or more of these vitamins, but they can improve certain neurological conditions even without a (proven) deficiency.

Aim

This review focuses on the most important biochemical mechanisms, how they are linked with neurological functions and what deficits arise from malfunctioning of these pathways.

Discussion

We discussed the main role of B Vitamins on several functions in the peripheral and central nervous system (PNS and CNS) including cellular energetic processes, antioxidative and neuroprotective effects, and both myelin and neurotransmitter synthesis. We also provide an overview of possible biochemical synergies between thiamine, pyridoxine, and cobalamin and discuss by which major roles each of them may contribute to the synergy and how these functions are inter‐related and complement each other.

Conclusion

Taking into account the current knowledge on the neurotropic vitamins B1, B6, and B12, we conclude that a biochemical synergy becomes apparent in many different pathways in the nervous system, particularly in the PNS as exemplified by their combined use in the treatment of peripheral neuropathy.

Vitamins in diet of patients with metabolic syndrome

Aim - analysis of data on the role of vitamin and carotenoid deficiency in the development of metabolic syndrome (MS), the consumption of individual vitamins and vitamin supplements, as well as estimation of the effectiveness of the use of vitamins in patients with MS. A review of the existing literature has been carried out in the databases of RINC, CyberLeninka, Google Scholar, Pubmed. The lack of vitamins is a risk factor for MS and its components. The diet of people with MS is characterized by excessive caloric content and at the same time contains an inadequate amount of most vitamins. The most frequent in patients with MS is the deficiency (blood level) of vitamin D, E, B vitamins, carotenoids. Among patients with MS, individuals with a reduced concentration of vitamins in the blood plasma are often found. In turn, among those with a deficiency of vitamins, MS is more often found. Low concentrations of 25(OH)D in the serum are associated with an increased risk of MS. An inverse association between the concentration of the hormonal form of vitamin 1.25(OH)2D3 in the serum and the development of MC has been found. In patients with MS, the α-tocopherol concentration associated with lipids is lower than in healthy individuals, and γ-tocopherol, on the contrary, is higher. Taking high doses of one of the vitamin E homologues shifts the balance between tocopherols in the blood plasma. Sufficient supply of the body with all vitamins involved in the formation of metabolically active forms of vitamins (D, B6, PP) is a necessary condition for the exercise of these biological functions by these vitamins. The lack of vitamins is a risk factor for MS and its components. Enrichment of the diet of patients with MS should be considered as a necessary favorable background for its treatment. Since the body has functional connections between vitamins, it is advisable to use not individual vitamins, but their complexes.

Myocardial dysfunction in relation to serum thiamine levels in children with diabetic ketoacidosis

Background Thiamine deficiency is commonly reported in patients with diabetes especially during diabetic ketoacidosis (DKA) that could attribute to myocardial dysfunction in those patients. However, there is limited data regarding its relation to myocardial function among those patients. This study aimed to explore the association between myocardial function and serum thiamine levels in children with type 1 diabetes mellitus (DM). Methods This cross-sectional comparative study included 25 patients with DKA. Clinical data assessment, echocardiographic examination and measurement of serum high-sensitive troponin T (hs-cTnT) and thiamine levels were done. We also assessed the association between troponin levels, echocardiographic ventricular systolic and diastolic function and serum thiamine. Results Twenty-four percent of children with DKA had thiamine deficiency. DKA children with thiamine deficiency had significant acidosis and higher serum troponin levels and significant impairment of diastolic function than those without thiamine deficiency. The serum thiamine level had a significant positive correlation with the echocardiographic indices of diastolic function but negative correlation with troponin levels. Conclusions Thiamine deficiency is a common finding during the treatment of children with DKA, and this deficiency may be associated with myocardial dysfunction.