Thiamine deficiency disorders: diagnosis, prevalence, and a roadmap for global control programs

Thiamine: An indispensable regulator of paediatric neuro-cardiovascular health and diseases

The sustainable developmental goals emphasize good health, reduction in preventable neonatal and under-five mortalities, and attaining zero hunger. However, South Asian countries report a higher incidence of neonatal and under-five mortalities when compared to the Western world, many of which are attributed to maternal and perinatal micronutrient deficiencies. Isolated nutrient deficiency in the absence of calorie deficit poses a diagnostic challenge since such deficiencies present with acute multisystemic and enigmatic manifestations. Thiamine (vitamin B1) is a micronutrient of prime importance which exerts indispensable roles in energy metabolism. Deficiency of thiamine can lead to catastrophic consequences. This review provides insight into the biochemical actions of thiamine in energy metabolism, the compromised aerobic metabolism resulting from thiamine deficiency, and the crucial role of thiamine in the proper functioning of the nervous, cardiovascular, and immune systems. The review also explores the acute life-threatening consequences of thiamine deficiencies in neonates and infants and the speculative role of thiamine in other pathologies like encephalopathy, sepsis, and autism spectrum disorders. However, routine assessment of thiamine in pregnant women and neonates is yet to be implemented, due to the lack of affordable and automated diagnostic techniques, and the cost-intensive nature of mass spectrometry-based quantification.

CONCLUSION

Physicians are recommended to have a low threshold for suspecting thiamine deficiency especially in vulnerable populations. Laboratory diagnosis of thiamine deficiency needs to be implemented as a standard of care, especially in endemic regions. Further, public health policies on food fortification, mandatory supplementation, and surveillance are imperative to eliminate thiamine deficiency-induced health hazards.

WHAT IS KNOWN

• South Asian countries report a higher incidence of neonatal and under-five mortalities, many of which are attributed to maternal and perinatal micronutrient deficiencies. • Preventable causes of neonatal/ infantile deaths include birth factors (low birth weight, birth asphyxia), infectious diseases (pneumonia, diarrhoea, tetanus, tuberculosis, measles, diphtheria, malaria, acute infections), deficiency diseases and genetic diseases (vitamin & mineral deficiencies, IEMs, congenital heart disease, unexplained PPHN, SIDS etc).

WHAT IS NEW

• Acute thiamine deficiency presenting as multisystemic syndromes, has unfortunately been a long standing unresolved public health concern. However, accessible surveillance and diagnostic strategies remain elusive in most clinical settings. • Despite decades of reports and emerging guidelines, diagnosis of thiamine deficiency is often missed and policy mandates at national level are yet to be implemented even in endemic countries. • This review provides a comprehensive summary of the biochemical role of thiamine, its key functions and effects on major organ systems, the diagnostic gap, the enigmatic presentation of acute thiamine deficiency, the plausible role of thiamine in other pathologies and the preventive measures at individual and community level.

Prevalence of thiamine deficiency in anorexia nervosa: a systematic review and narrative synthesis

Thiamine is an essential vitamin that plays a crucial role in many biochemical processes in the body. Anorexia nervosa (AN) is one potential cause of a state of deficiency which can result in grave medical sequelae. There is limited available evidence of the prevalence of thiamine deficiency in patients who suffer from AN. The current study aimed to systematically review all available evidence on the prevalence of thiamine deficiency in cohorts with AN. Studies were included where thiamine status in a group of participants with AN was measured, either through self-reporting or objective measurement. Eight databases (Scopus, CINAHL complete, Medline complete, EMBASE, WEB OF SCIENCE, PROSPERO, COCHRANE DATABASE OF SYSTEMATIC REVIEWS and Cochrane Central Register of Controlled Trials (CENTRAL) were searched. PRISMA guidelines were followed. The study was registered on PROSPERO. A minimum of two researchers conducted each part of the review. The search identified 42 articles whose full texts were screened for eligibility, with 17 retained for qualitative synthesis. The prevalence rates of thiamine deficiency in AN varied from 5.9% to 100% when based on self-report dietary intake. When objective measurements were taken, rates ranged from 0% to 56.7%. The review suggested that age, body mass index (BMI), duration of illness and subtype of AN were not associated with thiamine status. The limited available evidence suggested that the use of supplements, prior treatment and higher energy intakes were associated with a reduced risk of developing a thiamine deficiency among individuals with AN. Poor study methodology including small sample size, inconsistent deficiency definition and study heterogeneity limits the conclusions that can be drawn. Ultimately, there is insufficient strength of evidence to draw definitive clinical recommendations. This review highlights the need for further studies with more robust methodology to help further inform clinical practice.

Cross-Sectional Study of Thiamine Deficiency and Its Associated Risks in Emergency Care

Background

Growing data indicates that thiamine deficiency occurs during acute illness in the absence of alcohol use disorder. Our primary objective was to measure clinical factors associated with thiamine deficiency in patients with sepsis, diabetic ketoacidosis, and oncologic emergencies.

Methods

This was an analysis of pooled data from cross-sectional studies that enrolled adult emergency department (ED) patients at a single academic center with suspected sepsis, diabetic ketoacidosis, and oncologic emergencies. We excluded patients who had known alcohol use disorder or who had received ED thiamine treatment prior to enrollment. Investigators collected whole blood thiamine levels in addition to demographics, clinical characteristics, and available biomarkers. We defined thiamine deficiency as a whole blood thiamine level below the normal reference range and modeled the adjusted association between this outcome and age.

Results

There were 269 patients, of whom the average age was 57 years; 46% were female, and 80% were Black. Fifty-five (20.5%) patients had thiamine deficiency. In univariate analysis, age >60 years (odds ratio [OR] 2.5, 95% confidence interval [CI], 1.3-4.5), female gender (OR 1.9, 95% CI 1.0-3.4), leukopenia (OR 4.9, 95% CI 2.3-10.3), moderate anemia (OR 2.8, 95% CI 1.5-5.3), and hypoalbuminemia (OR 2.2, 95% CI 1.2-4.1) were associated with thiamine deficiency. In adjusted analysis, thiamine deficiency was significantly higher in females (OR 2.1, 95% CI 1.1-4.1), patients >60 years (OR 2.0, 95% CI 1.0-3.8), and patients with leukopenia (OR 5.1, 95% CI 2.3-11.3).

Conclusion

In this analysis, thiamine deficiency was common and was associated with advanced age, female gender, and leukopenia.

Treatment of nasopharyngeal carcinoma and prevention of non-alcoholic Wernicke's disease: A case report and review of literature

BACKGROUND

Wernicke encephalopathy is a neurological disorder caused by thiamine deficiency, commonly seen in alcoholic populations but also involving other circumstances that may lead to thiamine deficiency. The recognition of Wernicke encephalopathy often depends on clinicians' keen ability to detect its typical triad of features; however, most cases do not present with the full constellation of signs, which complicates the timely identification of Wernicke encephalopathy.

CASE SUMMARY

This case report describes a patient with nasopharyngeal carcinoma who developed abnormal ocular function and ataxia following concurrent chemoradiotherapy, without a history of alcohol abuse. With the aid of radiological examinations, he received a timely diagnosis and treatment; however, his symptoms did not fully resolve during follow-up.

CONCLUSION

For patients with malignant tumors exhibiting neurological symptoms, clinicians should consider the possibility of Wernicke encephalopathy and provide prophylactic thiamine therapy.

Clinical profile and thiamine transporter gene (SLC19A2 and SLC19A3) variations in infants with thiamine-responsive pulmonary hypertension and acute respiratory infection

Maternal thiamine deficiency is prevalent in low- and middle-income countries. Thiamine-responsive pulmonary hypertension (TRPHTN) in exclusively breastfed infants is reported in India. Thiamine transporter gene (ThTR) variations have not been studied. This study compared the presentation of exclusively breastfed infants with respiratory distress diagnosed as TRPHTN or acute respiratory infection (ARI). We investigated pathogenic variations in the SLC19A2 and SLC19A3 ThTr genes in a representative sample. Observational study. Tertiary care pediatric unit of a teaching hospital in southern India. Data collection was prospective. We included exclusively breastfed infants between 1 and 6 months of age with respiratory distress. Infants with PHTN in echocardiography and lactic acidosis (LA) received thiamine. TRPHTN was diagnosed based on response within 72 h. Infants with fever, chest findings, and positive microbiology were managed as ARI. The ThTr genes were sequenced and analyzed. Chi-square and stratified analysis were done to determine TRPHTN risk. Forty infants with TRPHTN and 42 with ARI were included. The median pulmonary arterial pressure in the TRPHTN group was 51.5 mmHg. Mild PHTN was seen in 65%, moderate in 22.5%, and severe in 12.5%. Cardiac failure (P < .001), stridor and aphonia (P < .001), encephalopathy (P = .024), LA (P < .001), and PHTN (P <.001) facilitated the diagnosis. The adjusted risk was 17.3 (95% confidence interval 7.8-38.3; P <.001). The ThTR sequencing showed wild-type genotypes. TRPHTN has a distinct, identifiable presentation. Lactate and pulmonary pressure estimations are useful investigations in thiamine deficiency endemic areas. We could not demonstrate a genetic variation that determines susceptibility.

Salt Reduction and Iodine Fortification Policies Are Compatible: Perspectives for Public Health Advocacy

Cardiovascular diseases account for almost 18 million deaths annually, the most of all non-communicable diseases. The reduction of dietary salt consumption is a modifiable risk factor. The WHO recommends a daily sodium intake of <2000 mg but average consumption exceeds this in many countries globally. Strategies proposed to aid effective salt reduction policy include product reformulation, front of pack labelling, behavioural change campaigns and establishing a low-sodium-supportive environment. Yet, salt for household and processed food use is, in countries wholly or partially adopting a universal salt iodisation policy, the principal vehicle for population-wide iodine fortification. With salt reduction policies in place, there is concern that iodine deficiency disorders may re-emerge. Recognising the urgency to tackle the rising prevalence of NCDs yet not risk the re-emergence and detrimental effect of inadequate iodine intakes, this review lays out the feasibility of integrating both salt reduction and salt iodine fortification strategies. Reducing the burden of health risks associated with an excessive sodium intake or inadequate iodine through population-tailored, cost-effective strategies involving salt is both feasible and achievable, and represents an opportunity to improve outcomes in public health.

High-resolution plasma metabolomics and thiamine status in critically Ill adult patients

INTRODUCTION

Thiamine (Vitamin B1) is an essential micronutrient and is classically considered a co-factor in energy metabolism. The association between thiamine status and whole-body metabolism in critical illness has not been studied.

OBJECTIVES

To determine association between whole blood thiamine pyrophosphate (TPP) concentrations and plasma metabolites and connected metabolic pathways using high resolution metabolomics (HRM) in critically ill patients.

METHODS

Cross-sectional study performed at Erciyes University Hospital, Kayseri, Turkey and Emory University, Atlanta, GA, USA. Participants were critically ill adults with an expected length of intensive care unit stay longer than 48 h and receiving chronic furosemide therapy. A total of 76 participants were included. Mean age was 69 years (range 33-92 years); 65% were female. Blood for TPP and metabolomics was obtained on the day of ICU admission. Whole blood TPP was measured by HPLC and plasma HRM was performed using liquid chromatography/mass spectrometry. Data was analyzed using regression analysis of TPP levels against all plasma metabolomic features in metabolome-wide association studies (MWAS). MWAS using the highest and lowest TPP concentration tertiles was performed as a secondary analysis.

RESULTS

Specific metabolic pathways associated with whole blood TPP levels in regression and tertile analysis included pentose phosphate, fructose and mannose, branched chain amino acid, arginine and proline, linoleate, and butanoate pathways.

CONCLUSIONS

Plasma HRM revealed that thiamine status, determined by whole blood TPP concentrations, was significantly associated with metabolites and metabolic pathways related to metabolism of energy, carbohydrates, amino acids, lipids, and the gut microbiome in adult critically ill patients.

Beriberi following sleeve gastrectomy

Bariatric surgery is being undertaken more frequently in response to rising levels of obesity but is increasingly also requested as a cosmetic choice. Nutritional deficiencies are a recognised consequence of gastrectomy, with potentially severe and permanent neurological sequelae. We present two cases of acute, severe polyneuropathy following sleeve gastrectomy. Severe thiamine deficiency was considered in both cases but with delayed proof and a significant initial differential diagnosis. Neurologists must have a high index of suspicion for the peripheral as well as central presentations of thiamine deficiency to avoid permanent disability. We also call for explicit information resources warning of the risk and signs of thiamine deficiency to be provided routinely to patients after gastrectomy.

The Weight of Bariatric Surgery: Wernicke-Korsakoff Syndrome after Vertical Sleeve Gastrectomy-A Case Series

In this case series, the simultaneous occurrence of Wernicke's encephalopathy (WE) and dry beriberi was reported in three patients who underwent vertical sleeve gastrectomy (VSG) between May 2021 and May 2023. All patients were obese women who underwent vertical sleeve gastrectomy (VSG) without immediate postoperative complications, but two weeks later, hyperemesis and subsequent encephalopathy with ocular movement abnormalities and weakness were observed over the following thirty days. Patients were referred to neurology, where due to the high suspicion of WE, thiamine replacement therapy was initiated; meanwhile, diagnostic neuroimaging and blood tests were conducted. Neurological and psychiatric evaluations and neuroconduction studies were performed to assess the clinical evolution and present sequelae. One year after diagnosis, all patients exhibited affective and behavioral sequelae, anterograde memory impairment, and executive functioning deficits. Two patients met the criteria for Korsakoff syndrome. Additionally, peripheral nervous system sequelae were observed, with all patients presenting with sensorimotor polyneuropathy. In conclusion, Wernicke's encephalopathy requires a high diagnostic suspicion for timely intervention and prevention of irreversible sequelae, which can be devastating. Therefore, raising awareness among medical professionals regarding the significance of this disease is essential.

OsTH1 is a key player in thiamin biosynthesis in rice

Thiamin is a vital nutrient that acts as a cofactor for several enzymes primarily localized in the mitochondria. These thiamin-dependent enzymes are involved in energy metabolism, nucleic acid biosynthesis, and antioxidant machinery. The enzyme HMP-P kinase/thiamin monophosphate synthase (TH1) holds a key position in thiamin biosynthesis, being responsible for the phosphorylation of HMP-P into HMP-PP and for the condensation of HMP-PP and HET-P to form TMP. Through mathematical kinetic model, we have identified TH1 as a critical player for thiamin biofortification in rice. We further focused on the functional characterization of OsTH1. Sequence and gene expression analysis, along with phylogenetic studies, provided insights into OsTH1 bifunctional features and evolution. The indispensable role of OsTH1 in thiamin biosynthesis was validated by heterologous expression of OsTH1 and successful complementation of yeast knock-out mutants impaired in thiamin production. We also proved that the sole OsTH1 overexpression in rice callus significantly improves B1 concentration, resulting in 50% increase in thiamin accumulation. Our study underscores the critical role of OsTH1 in thiamin biosynthesis, shedding light on its bifunctional nature and evolutionary significance. The significant enhancement of thiamin accumulation in rice callus upon OsTH1 overexpression constitutes evidence of its potential application in biofortification strategies.

Race explains substantial variance in whole blood thiamine diphosphate concentrations

Deficiency for thiamine (vitamin B1), traditionally assessed via the activity of the thiamine-dependent enzyme erythrocyte transketolase, has been reported in individuals with alcohol use disorder (AUD) and in people with HIV; concentrations of the metabolically active diphosphate form, however, have yet to be reported in HIV cohorts and results in AUD are equivocal. In this cross-sectional study, samples from 170 AUD, 130 HIV, and 100 healthy control individuals were analyzed to test the hypothesis that AUD and HIV groups relative to healthy controls would show low whole blood thiamine diphosphate (TDP) concentrations related to peripheral neuropathy. TDP concentrations were not different in the 3 study groups (P = .6141) but were lower in Black (n = 172) relative to White (n = 155) individuals (P < .0001) regardless of group. In a multiple regression, race relative to diagnoses explained more than 10 times the variance in whole blood TDP concentrations (F4,395 = 3.5, P = .0086; r2 = 15.1]. Performance on a measure of peripheral neuropathy (2-point discrimination) was worse in the HIV and AUD cohorts relative to the healthy control group (P < .0001) but was not associated with TDP concentrations. These findings suggest that Black individuals carry a heightened vulnerability for low whole blood TDP concentrations, but the clinical significance and mechanisms underlying these results remain to be determined.

Assessment of Erythrocyte Transketolase, Whole Blood Thiamine Diphosphate, and Human Milk Thiamine Concentrations to Identify Infants and Young Children Responding Favorably to Therapeutic Thiamine Administration: Findings from the Lao Thiamine Study, a Prospective Cohort Study

Background

There is limited information on relationships among biomarkers of thiamine status (whole blood thiamine diphosphate [ThDP], erythrocyte transketolase activity coefficient [ETKac], and human milk thiamine [MTh]) and clinical manifestations of thiamine deficiency.

Objectives

This study aimed to explore correlations among these biomarkers and thiamine responsive disorders (TRDs), a diagnosis based on favorable clinical response to thiamine.

Methods

Hospitalized infants and young children (aged 21 d to <18 mo) with respiratory, cardiac, and/or neurological symptoms suggestive of thiamine deficiency were treated with parenteral thiamine (100 mg daily) for ≥3 d alongside other treatments and re-examined systematically. Clinical case reports were reviewed by 3 pediatricians, who determined TRD or non-TRD status. Children in a community comparison group were matched by age, sex, and residence. Venous whole blood ThDP and MTh were determined by high-performance liquid chromatography fluorescence detection and ETKac in washed erythrocytes by ultraviolet spectrophotometry. Associations between biomarkers were assessed using Spearman correlations, and biomarker cutoffs predictive of TRD and ETKac >1.25 were explored using area under the receiver operating characteristic curve framework.

Results

Thiamine biomarkers were available for 287 hospitalized children and 228 community children (mean age 4.7 mo; 59.4% male). Median (interquartile range [IQR]) ThDP and ETKac were 66.9 nmol/L (IQR: 41.4, 96.9 nmol/L) and 1.25 nmol/L (IQR: 1.11, 1.48 nmol/L), respectively, among hospitalized children, and 64.1 nmol/L (IQR: 50.0, 85.3 nmol/L) and 1.22 nmol/L (IQR: 1.12, 1.37 nmol/L) among 228 community children (P > 0.05 for both). Forty-five percent of breastfeeding mothers of infants <6 mo had MTh <90 μg/L. ThDP and ETKac, but not MTh, were significantly different between 152 children with TRD and 122 without TRD, but overlapping distributions undermined prediction of individual responses to thiamine.

Conclusions

Although ETKac, ThDP, and MTh are useful biomarkers of population thiamine status, none of the biomarkers reliably identified individual children with TRD. ThDP is more practical for population assessment because preparing washed erythrocytes is not required.This trial was registered at clinicaltrials.gov as NCT03626337.

Reply to: Comment on: Malnutrition in heart failure with preserved ejection fraction

This letter comments on the letter by May in this issue.

Non-alcoholic Wernicke's Encephalopathy Masquerading As CNS Relapse of Acute Myeloid Leukemia

While Wernicke's encephalopathy (WE) is mostly caused by thiamine deficiency secondary to chronic alcohol use, other conditions that may affect one's nutritional status, such as bariatric surgery, hyperemesis gravidarum, chronic gastrointestinal disease, HIV/AIDS, and certain malignancies, may also lead to this outcome. We are discussing one such case, WE, in a young man with acute myeloid leukemia (AML) who underwent chemotherapy. The patient presented with blurred vision, paresthesia, weakness, and vomiting. Although he denied alcohol abuse, his symptoms, physical exam findings, and MRI results were consistent with WE. Treatment with thiamine resulted in a significant improvement in his visual disturbances and mental status. The authors highlight the importance of recognizing WE in non-alcoholic patients, particularly those undergoing prolonged hospitalization and chemotherapy, as nutritional deficiencies can develop. They recommend thiamine supplementation for patients receiving chemotherapy and those with poor oral intake. The case underscores the need for high clinical suspicion and early intervention in atypical cases of WE.

A Case Report of Refractory Hyperlactatemia Secondary to Thiamine Deficiency

Thiamine is an essential water-soluble vitamin that must be obtained through diet. This vitamin is crucial for various biochemical reactions and is vital for aerobic metabolism. When individuals are deficient in thiamine, which can be due to hypermetabolism (such as in inflammation, ischemia, or malnutrition, among other reasons), anaerobic metabolism may be utilized to maintain energy needs. Such chemical processes produce lactic acid. Excess lactic acid can cause various clinical signs and symptoms, though lactate dehydrogenase (LDH) can typically break down this compound. The following case presents a very unusual instance where a 51-year-old Caucasian woman presented with the chief complaint of ongoing and severe abdominal pain. After an extensive work-up ruling out numerous diagnoses and an eight-day hospital stay, it was believed that she may be suffering from hyperlactatemia secondary to thiamine deficiency, as she improved significantly after administration of this vitamin. It was thought that this was likely due to her previous systemic lupus erythematosus (SLE) diagnosis, vasculitis, chronic inflammation, and a hypermetabolic state, in addition to concurrent LDH malfunction.

The effect of psychoactive bacteria, Bifidobacterium longum Rosell®-175 and Lactobacillus rhamnosus JB-1, on brain proteome profiles in mice

RATIONALE

The gut microbiota may play an important role in the development and functioning of the mammalian central nervous system. The assumption of the experiment was to prove that the use of probiotic bacterial strains in the diet of mice modifies the expression of brain proteins involved in metabolic and immunological processes.

OBJECTIVES AND RESULTS

Albino Swiss mice were administered with Bifidobacterium longum Rosell®-175 or Lactobacillus rhamnosus JB-1 every 24 h for 28 days. Protein maps were prepared from hippocampal homogenates of euthanized mice. Selected proteins that were statistically significant were purified and concentrated and identified using MALDI-TOF mass spectrometry. Among the analysed samples, 13 proteins were identified. The mean volumes of calcyon, secreted frizzled-associated protein 3, and catalase in the hippocampus of mice from both experimental groups were statistically significantly higher than in the control group. In mice supplemented with Lactobacillus rhamnosus JB-1, a lower mean volume of fragrance binding protein 2, shadow of prion protein, and glycine receptor α4 subunit was observed compared to the control.

CONCLUSION

The psychobiotics Bifidobacterium longum Rosell®-175 and Lactobacillus rhamnosus JB-1enhances expression of proteins involved in the activation and maturation of nerve cells, as well as myelination and homeostatic regulation of neurogenesis in mice. The tested psychobiotics cause a decrease in the expression of proteins associated with CNS development and in synaptic transmission, thereby reducing the capacity for communication between nerve cells. The results of the study indicate that psychobiotic bacteria can be used in auxiliary treatment of neurological disorders.

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.

Vitamin deficiencies in children: Lessons from clinical and neuroimaging findings

BACKGROUND AND AIMS

Water-soluble vitamins play an essential coenzyme role in the nervous system. Acquired vitamin deficiencies are easily treatable, however, without treatment, they can lead to irreversible complications. This study aimed to provide clinical, laboratory parameters and neuroimaging data on vitamin deficiencies in an attempt to facilitate early diagnosis and prompt supplementation.

METHODS

From July 1998 to July 2023, patients at Necker-Enfants-Malades Hospital presenting with acute neurological symptoms attributed to acquired vitamin deficiency were included. Clinical data were extracted from Dr Warehouse database. Neuroimaging, biochemical and electrophysiological data were reviewed.

RESULTS

Patients with vitamin B1 deficiency exhibited abnormal eye movements (n = 4/4), fluctuations in consciousness (n = 3/4), and ataxia (n = 3/4). Brain MRI showed alterations of fourth ventricle region (n = 4/4), periaqueductal region (n = 4/4), tectum (n = 3/4), and median thalami (n = 3/4). Patients with vitamin B2 deficiency presented with early onset hypotonia (n = 3/4), hyperlactatemia (n = 4/4), and hyperammonemia (n = 4/4). Plasma acylcarnitines revealed a multiple acyl-coA dehydrogenase deficiency-like profile (n = 4/4). In vitamin B12 deficiency, young children presented with developmental delay (n = 7/7) and older children with proprioceptive ataxia (n = 3/3). Brain MRI revealed atrophy (n = 7/7) and spinal MRI hyperintensity in posterior cervical columns (n = 3/3). Metabolic findings showed elevated methylmalonic acid (n = 6/7) and hyperhomocysteinemia (n = 6/7). Patients with vitamin C deficiency exhibited gait disturbances and muscle weakness (n = 2/2).

CONCLUSIONS

Acquired vitamin deficiencies may display reversible clinical symptoms mimicking inherited metabolic disorders. Some situations raise suspicion for diagnosis: concordant clinical presentation, suggestive neuroimaging findings, and/or biochemical evidence. Any acute neurological condition should be treated without waiting for definitive biochemical confirmation.

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.

Correlation of Serum Sodium and Potassium With Thiamin Levels in Type 1 and Type 2 Diabetic Patients

Introduction Chronic metabolic disorders such as diabetes mellitus (DM) are becoming a global health concern. According to recent studies, the pathophysiology of DM may involve factors other than traditional glycemic control, such as electrolyte balance and thiamin status. Therefore, this study evaluated the relationship between sodium and potassium and serum thiamin levels in patients with type 1 and type 2 DM. Methods This study was conducted in multiple diabetic outpatient clinics and centers in Karachi, Pakistan, using a non-probability convenience sampling method. The study lasted for approximately six months after the synopsis was approved. A total of 64 patients were selected, 32 of whom each had type 1 and type 2 DM. All patients who were between the ages of 25 and 46 years old and had either type 1 or type 2 DM were included in the study. A Mann-Whitney test and an independent t-test were used to compare the means between the two study groups. Pearson's correlation and chi-square tests were used to determine the variables, correlations, and associations with type 1 and type 2 DM. Results The study findings showed that the distribution of gender among diabetic patients revealed that among males, eight (25.0%) had type 1 DM, and 10 (31.2%) had type 2 DM. Among females, 24 (75.0%) had type 1 DM, and 22 (68.8%) had type 2 DM. Significant correlations were observed in the means of blood glucose levels, such as glycated hemoglobin (HbA1c), fasting blood sugar (FBS), and serum thiamin levels, among patients with type 1 and type 2 DM (p < 0.001). The HbA1c, FBS, and serum thiamin levels were significantly higher in type 2 DM patients than in type 1 DM patients. Among patients with type 1 DM, sodium levels were not substantially correlated with thiamin levels (p = 0.570, r = 0.104), whereas potassium levels were significantly correlated with thiamin levels (p = 0.005, r = 0.263). Conclusion We conclude that the sodium level was not significantly correlated with serum thiamin status in type 1 and type 2 DM, whereas a low positive correlation was observed between potassium and serum thiamin levels in type 1 DM. However, there was no significant correlation concerning potassium levels in type 2 DM.

Thiamine deficiency-related neuropathy: A reversible entity from an endemic area

BACKGROUND AND PURPOSE

Despite thiamine deficiency being a lesser-known entity in modern times, beriberi in various forms, including thiamine deficiency-related neuropathy, remains endemic in Kashmir due to the consumption of polished rice as a staple food. This observational study investigates cases of peripheral neuropathy of unknown etiology and their potential responsiveness to thiamine administration.

METHODS

This prospective study enrolled adult patients presenting to the emergency department with weakness consistent with thiamine deficiency-related neuropathy and conducted a therapeutic challenge with thiamine on 41 patients. Response to thiamine therapy was monitored based on subjective and objective improvements in weakness and power. Patients were divided into thiamine responders (n = 25) and nonresponders (n = 16) based on their response to thiamine therapy and nerve conduction studies.

RESULTS

Most of the baseline characteristics were similar between responders and nonresponders, except the responders exhibited lower thiamine levels and higher partial pressure of oxygen and lactate levels compared to nonresponders. All patients had a history of consuming polished rice and traditional salt tea. Although weakness in the lower limbs was present in both groups, nonresponders were more likely to exhibit weakness in all four limbs. Clinical improvement was observed within 24 h, but proximal muscle weakness persisted for an extended period of time.

CONCLUSIONS

Thiamine deficiency-related neuropathy presents with predominant lower limb weakness, exacerbated by vomiting, poor food intake, psychiatric illness, and pregnancy. Thiamine challenge should be followed by observation of clinical and biochemical response.

Association between dietary vitamin B1 intake and cognitive function among older adults: a cross-sectional study

BACKGROUND

This study aims to investigate the relationship between vitamin B1 intake and cognitive function in older adults.

METHODS

This cross-sectional observational study utilized data from the National Health and Nutrition Examination Survey (NHANES) 2011-2014. A total of 2422 participants were included in the analysis, with dietary vitamin B1 intake being determined by averaging two 24-h dietary recalls. Cognitive function was assessed using three cognitive function tests: the Digit Symbol Substitution Test (DSST) for processing speed, the Animal Fluency Test (AFT) for executive function, a Consortium to Establish a Registry for Alzheimer's disease (CERAD) subtest for memory. Test-specific and global cognition z score was created. Multivariate linear regression models were used to explore the association between vitamin B1 and cognitive function.

RESULTS

2422 participants, aged 60 years and older, were included from NHANES across two survey cycles (2011-2014). Higher vitamin B1 intake was associated with higher DSST, AFT scores (P < 0.001) as well as the global cognition z score (P = 0.008). In the fully adjusted model, as compared to the lowest quartile (Q1), the highest quartile (Q4) of vitamin B1 intake was related to higher DSST score (β = 2.23, 95% CI 0.79 ~ 3.67) and global cognition z sore (β = 0.09, 95% CI 0.02 ~ 0.16). The association between dietary vitamin B1 intake and cognitive function scores in US adults is linear. There was no detected significant statistical interaction between these variables.

CONCLUSIONS

Increased dietary intake of vitamin B1 was associated with better cognitive function in individuals aged over 60.

Characterization of an Acinetobacter baumannii Monofunctional Phosphomethylpyrimidine Kinase That Is Inhibited by Pyridoxal Phosphate

Thiamin and its phosphate derivatives are ubiquitous molecules involved as essential cofactors in many cellular processes. The de novo biosynthesis of thiamin employs the parallel synthesis of 4-methyl-5-(2-hydroxyethyl)thiazole (THZ-P) and 4-amino-2-methyl-5(diphosphooxymethyl) pyrimidine (HMP) pyrophosphate (HMP-PP), which are coupled to generate thiamin phosphate. Most organisms that can biosynthesize thiamin employ a kinase (HMPK or ThiD) to generate HMP-PP. In nearly all cases, this enzyme is bifunctional and can also salvage free HMP, producing HMP-P, the monophosphate precursor of HMP-PP. Here we present high-resolution crystal structures of an HMPK from Acinetobacter baumannii (AbHMPK), both unliganded and with pyridoxal 5-phosphate (PLP) noncovalently bound. Despite the similarity between HMPK and pyridoxal kinase enzymes, our kinetics analysis indicates that AbHMPK accepts HMP exclusively as a substrate and cannot turn over pyridoxal, pyridoxamine, or pyridoxine nor does it display phosphatase activity. PLP does, however, act as a weak inhibitor of AbHMPK with an IC50 of 768 μM. Surprisingly, unlike other HMPKs, AbHMPK catalyzes only the phosphorylation of HMP and does not generate the diphosphate HMP-PP. This suggests that an additional kinase is present in A. baumannii, or an alternative mechanism is in operation to complete the biosynthesis of thiamin.

Wernicke Syndrome: Case Report and Literature Review of Contributing Factors-Can Malpractice Dynamics Be Identified?

Wernicke Encephalopathy (WE) is a neurological acute syndrome related to vitamin B1 deficiency and is relatively common in patients with chronic alcoholism. In the case of Hyperemesis Gravidarum, thiamine body stores become unable to meet the increased demand, resulting in acute deficiency. WE is associated with typical clinical and radiological findings. Treatment pathways rely on thiamine replacement. The case herein reported is centered around a 33-year-old diabetic patient at 12 weeks of gestation, with WE due to hyperemesis gravidarum. The disease manifested itself with weakness, mental confusion, headache, and impaired vision. The diagnosis was established after the detection of typical findings by MRI. Thirty days after therapy was started, most of the patient's neurological disorders were resolved. The patient was discharged 40 days later with instructions to continue daily thiamine supplementation. The pregnancy outcome was good. Unfortunately, mild ataxia persisted in 2-year follow-up as a long-term consequence. When diagnosed and treated, WE has a favorable prognosis. However, roughly 80% of patients experience memory loss, which may continue for a long time, while gait disorders reportedly affect about 35% of patients. Mild ataxia and dysmetria may persist, too. We reviewed the scientific literature on WE in women with HG until February 2023. Hardly any authors report data on long-term sequelae. Our report emphasizes how important it is to take into consideration this complication in clinical practice, referring to published guidelines and recommendations. Neurological maternal sequelae can demonstrably persist despite early diagnosis and appropriate management. For this reason, a long-term follow-up is recommended. Wernicke syndrome management cannot yet rely on well-established conclusive guidelines; hence, a cautionary approach ought to be prioritized in order to ensure medicolegal soundness.

Descriptive spectrum of thiamine deficiency in pregnancy: A potentially preventable condition

OBJECTIVE

Pregnancy, a nutritionally demanding situation in terms of macro- and micronutrient supply owing to heightened maternal, placental, and fetal needs, significantly affects thiamine reserves. Thiamine deficiency during pregnancy and the postpartum period, presenting with varied manifestations and outcomes, is a relatively common condition in our population. The study aimed to understand the various manifestations and outcomes of acute thiamine deficiency in pregnant and postpartum women, emphasizing the significance of early recognition and thiamine therapy to prevent serious complications during pregnancy and after childbirth.

METHODS

This prospective study conducted in a tertiary care center in North India enrolled consecutive pregnant and postpartum women presenting with clinical features consistent with thiamine deficiency disorders, such as thiamine deficiency-related neuropathy, high-output heart failure, heart failure with reduced ejection fraction, Wernicke's encephalopathy, gastric beriberi, and thiamine-responsive acute pulmonary hypertension. In addition to capturing medical history including drug intake, dietary consumption, and comorbidities, women underwent brief relevant clinical examinations and laboratory assessments, including whole-blood thiamine levels. Response to intravenous thiamine supplementation was also monitored.

RESULTS

Data of 31 women (12 pregnant, 19 postpartum) with a diagnosis of acute thiamine deficiency and a mean age of 28.88 ± 2.69 years were analyzed. The mean thiamine level was 1.28 ± 0.44 μg/dL with mean blood lactate of 3.46 ± 3.33. The most common presentation was gastric beriberi (n = 10), followed by paraparesis (n = 6), high-output heart failure (n = 6), acute pulmonary hypertension, heart failure with reduced ejection fraction (n = 3 each), and an acute confusional state (n = 2). All patients responded to thiamine challenge.

CONCLUSION

In the context of borderline thiamine status, particularly in our population with endemic thiamine deficiency and heightened demand for thiamine during pregnancy and the peripartum period, the deficiency can have varied and serious manifestations of dry and wet beriberi. Early recognition of the clinical features and thiamine therapy can be life-saving. There is a need for validated clinical criteria owing to the non-availability of thiamine testing in resource-limited settings.

Vitamin B6 and vitamin D deficiency co-occurrence in geriatric memory patients

INTRODUCTION

Vitamin B6 and D levels are not assessed routinely in geriatric memory patients. This study examined vitamin levels to determine the potential effects on cognition.

METHODS

A chart review was conducted of 203 consecutive patients over a 12-month period. Levels of vitamins B1, B6, B12, and D were obtained on the day of clinic to identify deficiencies. A mental status exam (Mini Mental State Examination [MMSE]) was also performed.

RESULTS

One hundred sixty-seven patients had one or more vitamin levels obtained on the day of clinical evaluation. Vitamin B6 deficiency was the most common (37.5%), followed by vitamin D deficiency (36.8%). A chi-square test revealed significant co-occurrence of deficiency of vitamins B6 and D (p < 0.001). Vitamin B6 and D deficiencies were associated with lower MMSE scores (p < 0.05).

DISCUSSION

Vitamin B6 and D deficiencies are common in geriatric patients. The coexistence of these vitamin deficiencies has a significant association with cognitive performance, indicating the clinical importance of monitoring and supplementation.

Silent Echoes: A Case Report of Wernicke Encephalopathy's Unheard Voice

Wernicke encephalopathy (WE) is an acute neuropsychiatric emergency that is caused by a deficiency in vitamin B1 (thiamine). This condition is most commonly seen in patients with alcohol use disorder; however, patients with other disorders of severe malnourishment are also at increased risk. In severe cases, this disease may be followed by Korsakoff's psychosis and even death.  We present a case of a 64-year-old African American female with a history of alcohol use disorder who presented to the emergency department on account of an acute confusional state. Neurological examination revealed right beating nystagmus on the left gaze and a wide-based gait. Initial laboratory work-up was unrevealing; however, magnetic resonance imaging (MRI) of the brain demonstrated an abnormal T2 fluid-attenuated inversion recovery (FLAIR) signal involving the bilateral mammillary bodies and surrounding lateral ventricles that extended into the periaqueductal parenchyma. The patient was admitted to the neurology unit, and high-dose intravenous thiamine was commenced. During hospitalization, the patient's confusion improved and they were subsequently discharged with oral thiamine. The spectrum of severity of WE is wide, ranging from fatal disease and can lead to permanent brain damage or even Korsakoff syndrome, characterized by severe memory loss and confabulation. The diagnosis is mainly clinical and based on the presence of symptoms in the classic triad of mental status change, oculomotor abnormality, and ataxia. This triad is only present in about 10% of cases, making the diagnosis very challenging. Laboratory testing can assist in making the diagnosis, but it is not always reliable or available. In situations of clinical uncertainty, imaging may also be used to support diagnosis or rule out other differentials. The mainstay of treatment is with high-dose parenteral thiamine.

A protocol for a turbidimetric assay using a Saccharomyces cerevisiae thiamin biosynthesis mutant to estimate total vitamin B1 content in plant tissue samples

BACKGROUND

Understanding thiamin (thiamine; vitamin B1) metabolism in plants is crucial, as it impacts plant nutritional value as well as stress tolerance. Studies aimed at elucidating novel aspects of thiamin in plants rely on adequate assessment of thiamin content. Mass spectrometry-based methods provide reliable quantification of thiamin as well as closely related biomolecules. However, these techniques require expensive equipment and expertise. Microbiological turbidimetric assays can evaluate the presence of thiamin in a given sample, only requiring low-cost, standard lab equipment. Although these microbiological assays do not reach the accuracy provided by mass spectrometry-based methods, the ease with which they can be deployed in an inexpensive and high-throughput manner, makes them a favorable method in many circumstances. However, the thiamin research field could benefit from a detailed step-by-step protocol to perform such assays as well as a further assessment of its potential and limitations.

RESULTS

Here, we show that the Saccharomyces cerevisiae thiamin biosynthesis mutant thi6 is an ideal candidate to be implemented in a turbidimetric assay aimed at assessing the content of thiamin and its phosphorylated equivalents (total vitamer B1). An optimized protocol was generated, adapted from a previously established microbiological assay using the thi4 mutant. A step-by-step guidance for this protocol is presented. Furthermore, the applicability of the assay is illustrated by assessment of different samples, including plant as well as non-plant materials. In doing so, our work provides an extension of the applicability of the microbiological assay on top of providing important considerations upon implementing the protocol.

CONCLUSIONS

An inexpensive, user-friendly protocol, including step-by-step guidance, which allows adequate estimation of vitamer B1 content of samples, is provided. The method is well-suited to screen materials to identify altered vitamer B1 content, such as in metabolic engineering or screening of germplasm.

Individual- and supply-level macronutrient intakes are well correlated over a 50-year period (1961-2011) in 18 countries in Asia, North America, and Europe

Reliable information on dietary trends is essential. We compared individual-level dietary estimates for total energy, carbohydrate, fat, and protein intake over time with national supply data from the Global Expanded Nutrient Supply Model (186 paired estimates from 1961 to 2011, 18 countries). We hypothesized that supply data would overestimate individual measures and that the two measures would be weakly correlated. Individual- and supply-level estimates were compared using Spearman correlation coefficients and linear mixed-effect models were used to estimate the differences between measures. Overall, the correlations between individual- and supply-level measures were moderate for energy (rs = 0.34) and carbohydrate (rs = 0.39), strong for fat (rs = 0.85), and protein (rs = 0.69). Trends in total energy measured by individual-level surveys and total energy supply were positively correlated in 38.9% of countries, whereas trends in macronutrients aligned between estimates in most countries. Supply-level dietary data overestimated individual-level intakes, especially in higher income countries in Europe and in the United States. In the United States, supply-level data exceeded individual-level estimates by 26.3% to 29.9% for energy, carbohydrate, and fat, whereas protein estimates were similar between measures. In Europe, supply-level estimates overestimated individual-level intake by 19.9% for energy, 17.0% for carbohydrate, 13.7% for fat, and 7.7% for protein, whereas estimates for energy and macronutrients were similar in Asia. In Asia and lower income countries, our findings generally support the use of supply-level data in the absence of individual-level data, though this finding may be related to smaller sample size and differences in underlying national statistics that inform supply data.

Evolutionary and ecological correlates of thiaminase in fishes

Thiamine (vitamin B1) is required by all living organisms in multiple metabolic pathways. It is scarce in natural systems, and deficiency can lead to reproductive failure, neurological issues, and death. One major cause of thiamine deficiency is an overreliance on diet items containing the enzyme thiaminase. Thiaminase activity has been noted in many prey fishes and linked to cohort failure in salmonid predators that eat prey fish with thiaminase activity, yet it is generally unknown whether evolutionary history, fish traits, and/or environmental conditions lead to production of thiaminase. We conducted literature and GenBank BLAST sequence searches to collect thiaminase activity data and sequence homology data in expressed protein sequences for 300 freshwater and marine fishes. We then tested whether presence or absence of thiaminase could be predicted by evolutionary relationships, trophic level, omega-3 fatty acid concentrations, habitat, climate, invasive potential, and body size. There was no evolutionary relationship with thiaminase activity. It first appears in Class Actinoptergyii (bony ray-finned fishes) and is present across the entire Actinoptergyii phylogeny in both primitive and derived fish orders. Instead, ecological factors explained the most variation in thiaminase: fishes were more likely to express thiaminase if they fed closer to the base of the food web, were high in polyunsaturated fatty acids, lived in freshwater, and were from tropical climates. These data provide a foundation for understanding sources of thiaminase leading to thiamine deficiency in fisheries and other organisms, including humans that eat uncooked fish.

An Overview of Type B Lactic Acidosis Due to Thiamine (B1) Deficiency

Type B lactic acidosis can occur secondary to several factors, including thiamine deficiency, and is not as common as type A. Recognizing thiamine deficiency-associated lactic acidosis is challenging because serum thiamine concentrations are not routinely obtained, and a thorough and specific history is necessary for clinicians to suspect thiamine deficiency as a root cause. Furthermore, the appropriate dose and duration of thiamine treatment are not well defined. Untreated thiamine deficiency-associated lactic acidosis can lead to critical illness requiring lifesaving extracorporeal therapies. Additionally, if thiamine and glucose are not administered in an appropriate sequence, Wernicke encephalopathy or Korsakoff syndrome may occur. This review aims to summarize therapeutic treatment for thiamine deficiency-associated lactic acidosis, based on case reports/series and nutritional guidance. After a literature search of the PubMed database, 63 citations met inclusion criteria, of which 21 involved pediatric patients and are the focus of this review. -Citations describe dosing regimens ranging from 25 to 1000 mg of intravenous (IV) thiamine as a single dose, or multiple daily doses for several days. Specific guidance for critically ill adults recommends a thiamine range of 100 mg IV once daily to 400 mg IV twice daily. Although there are no specific recommendations for the pediatric population, given the relative safety of thiamine administration, its low cost, and our review of the literature, treatment with thiamine 100 to 200 mg IV at least once is supported, with ongoing daily doses based on clinical response of the patient, regardless of age.

Severe Lactic Acidosis Caused by Thiamine Deficiency in a Child with Relapsing Acute Lymphoblastic Leukemia: A Case Report

Lactic acidosis is characterized by an excessive production of lactic acid or by its impaired clearance. Thiamine deficiency is an uncommon cause of lactic acidosis, especially in countries where malnutrition is rare. We describe the case of a 5-year-old boy who presented with a central nervous system relapse of acute lymphoblastic leukemia. During the chemotherapy regimen, the patient developed drug-induced pancreatitis with paralytic ileus requiring prolonged glucosaline solution infusion. In the following days, severe lactic acidosis (pH 7.0, lactates 253 mg/dL, HCO3- 8 mmol/L) was detected, associated with hypoglycemia (42 mg/dL) and laboratory signs of acute liver injury. Due to the persistent hypoglycemia, the dextrose infusion was gradually increased. Lactates, however, continued to raise, so continuous venovenous hemodiafiltration was started. While lactates initially decreased, 12 h after CVVHDF suspension, they started to raise again. Assuming that it could have been caused by mitochondrial dysfunction due to vitamin deficiency after prolonged fasting and feeding difficulties, parenteral nutrition and thiamine were administered, resulting in a progressive reduction in lactates, with the normalization of pH during the next few hours. In the presence of acute and progressive lactic acidosis in a long-term hospitalized patient, thiamine deficiency should be carefully considered and managed as early as possible.

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.

Correlation of Fasting Blood Sugar and Glycated Hemoglobin (HbA1c) With Thiamine Levels in Diabetic Patients

Introduction It has been discovered that low levels of thiamine reserves in the body are related to diabetes mellitus (DM) because thiamine directly influences carbohydrate metabolism. Therefore, the purpose of this study was to assess several metabolic variables and blood thiamine levels in patients with type 1 and type 2 DM and compare them with those in a control group of healthy individuals. Methods This case-control study was conducted at multiple diabetic outpatient centers in Karachi. A total of 90 participants, who were divided into three groups, each containing 30 individuals, were chosen using a convenient non-probability sampling technique. Group A served as the control group and consisted of healthy, non-diabetic individuals. Groups B and C contained subjects with type 1 and type 2 DM, respectively. Descriptive analysis was reported as mean standard deviation, whereas gender and comorbidities were expressed as frequencies and percentages. The chi-square test and Pearson's correlation coefficient were used to determine the associations of the variables with type 1 DM, type 2 DM, and controls. Results The study results revealed statistically significant differences between controls, type 1 and type 2 DM, in the means of blood glucose levels and all lipid profiles, such as glycated hemoglobin (HbA1c), fasting blood sugar (FBS), random blood sugar (RBS), serum thiamine, triglycerides (p < 0.001), high-density lipoprotein (HDL) (p = 0.014), and total cholesterol (p = 0.013). Furthermore, it was shown that among the control group, type 1 and type 2 DM, HbA1c, and FBS were insignificantly correlated with thiamine levels, whereas the HbA1c and FBS of the combined diabetic groups were significantly correlated with the thiamine level (r = 0.465, p < 0.001) and (r = 0.360, p = 0.005), respectively, where 'r' is the Pearson correlation coefficient. Additionally, HbA1c and FBS in the combined three groups were significantly correlated with the thiamine level (r = -0.626, p < 0.001) and (r = -0.561, p < 0.001), respectively. Conclusion This study concluded that patients with type 1 and type 2 DM had significantly higher levels of FBS, RBS, HbA1c, triglycerides, and total cholesterol than controls. Furthermore, both type 1 and type 2 DM patients' serum thiamine and HDL levels were observed to be considerably lower than those of controls. Additionally, among both types of DM and controls, there was a strong correlation between FBS and HbA1c. Therefore, we recommend that serum thiamine levels be routinely monitored in diabetic patients, and thiamine supplementation should be considered to avoid complications, especially vascular complications of DM.

The Impacts of Slc19a3 Deletion and Intestinal SLC19A3 Insertion on Thiamine Distribution and Brain Metabolism in the Mouse

The Thiamine Transporter 2 (THTR2) encoded by SLC19A3 plays an ill-defined role in the maintenance of tissue thiamine, thiamine monophosphate, and thiamine diphosphate (TDP) levels. To evaluate the impact of THTR2 on tissue thiamine status and metabolism, we expressed the human SLC19A3 transgene in the intestine of total body Slc19a3 knockout (KO) mice. Male and female wildtype (WT) and transgenic (TG) mice were fed either 17 mg/kg (1×) or 85 mg/kg (5×) thiamine hydrochloride diet, while KOs were only fed the 5× diet. Thiamine vitamers in plasma, red blood cells, duodenum, brain, liver, kidney, heart, and adipose tissue were measured. Untargeted metabolomics were performed on the brain tissues of groups with equivalent plasma thiamine. KO mice had ~two- and ~three-fold lower plasma and brain thiamine levels than WT on the 5× diet. Circulating vitamers were sensitive to diet and equivalent in TG and WT mice. However, TG had 60% lower thiamine but normal brain TDP levels regardless of diet, with subtle differences in the heart and liver. The loss of THTR2 reduced levels of nucleic acid and amino acid derivatives in the brain. Therefore, mutation or inhibition of THTR2 may alter the brain metabolome and reduce the thiamine reservoir for TDP biosynthesis.

Association Between Vitamin Deficiencies and Ophthalmological Conditions

Vitamin deficiencies can have adverse effects on health, including on the visual system. The ocular manifestations of a vitamin deficiency are related to the underlying biochemical function of the particular nutrient. While vitamin deficiencies are not common in developed counties, they are still prevalent in parts of the developing world and in specific, vulnerable populations. Vitamin deficiencies can cause or contribute to many ophthalmological conditions and eye diseases may even be the first presenting finding of a vitamin deficiency. As such, it is important for ophthalmologists to be aware of the ocular manifestations of vitamin deficiencies, especially given that the complications can be severe and effectively treated if identified early. This review summarizes the literature on the main vitamins known to have characteristic ocular manifestations: vitamins A, B1, B2, B9, B12, C, D, E and K. The function, epidemiology, manifestations, workup, and management of each vitamin is discussed in detail.

Synthetic Thioesters of Thiamine: Promising Tools for Slowing Progression of Neurodegenerative Diseases

Thiamine (vitamin B1) is essential for the brain. This is attributed to the coenzyme role of thiamine diphosphate (ThDP) in glucose and energy metabolism. The synthetic thiamine prodrug, the thioester benfotiamine (BFT), has been extensively studied and has beneficial effects both in rodent models of neurodegeneration and in human clinical studies. BFT has no known adverse effects and improves cognitive outcomes in patients with mild Alzheimer's disease. In cell culture and animal models, BFT has antioxidant and anti-inflammatory properties that seem to be mediated by a mechanism independent of the coenzyme function of ThDP. Recent in vitro studies show that another thiamine thioester, O,S-dibenzoylthiamine (DBT), is even more efficient than BFT, especially with respect to its anti-inflammatory potency, and is effective at lower concentrations. Thiamine thioesters have pleiotropic properties linked to an increase in circulating thiamine concentrations and possibly in hitherto unidentified open thiazole ring derivatives. The identification of the active neuroprotective metabolites and the clarification of their mechanism of action open extremely promising perspectives in the field of neurodegenerative, neurodevelopmental, and psychiatric conditions. The present review aims to summarize existing data on the neuroprotective effects of thiamine thioesters and give a comprehensive account.

Comparison of beriberi cases in indigenous and non-indigenous people, Brazil, 2013 to 2018

Beriberi is the clinical manifestation of severe and prolonged thiamine (vitamin B1) deficiency. It is a neglected disease that affects low-income populations facing food and nutrition insecurity. The aim of this study was to compare cases of beriberi among indigenous and non-indigenous people in Brazil. We conducted a cross-sectional study using data on cases of beriberi during the period July 2013-September 2018 derived from beriberi notification forms available on the FormSUS platform. Cases in indigenous and non-indigenous patients were compared using the chi-squared test or Fisher's exact test, adopting a significance level of 0.05. A total of 414 cases of beriberi were reported in the country during the study period, 210 of which (50.7%) were among indigenous people. Alcohol consumption was reported by 58.1% of the indigenous patients and 71.6% of the non-indigenous patients (p = 0.004); 71.0% of the indigenous patients reported that they consumed caxiri, a traditional alcoholic drink. Daily physical exertion was reported by 76.1% of the indigenous patients and 40.2% of the non-indigenous patients (p < 0.001). It is concluded that beriberi disproportionately affects indigenous people and is associated with alcohol consumption and physical exertion.

Availability of abundant thiamine determines efficiency of thermogenic activation in human neck area derived adipocytes

Brown/beige adipocytes express uncoupling protein-1 (UCP1) that enables them to dissipate energy as heat. Systematic activation of this process can alleviate obesity. Human brown adipose tissues are interspersed in distinct anatomical regions including deep neck. We found that UCP1 enriched adipocytes differentiated from precursors of this depot highly expressed ThTr2 transporter of thiamine and consumed thiamine during thermogenic activation of these adipocytes by cAMP which mimics adrenergic stimulation. Inhibition of ThTr2 led to lower thiamine consumption with decreased proton leak respiration reflecting reduced uncoupling. In the absence of thiamine, cAMP-induced uncoupling was diminished but restored by thiamine addition reaching the highest levels at thiamine concentrations larger than present in human blood plasma. Thiamine is converted to thiamine pyrophosphate (TPP) in cells; the addition of TPP to permeabilized adipocytes increased uncoupling fueled by TPP-dependent pyruvate dehydrogenase. ThTr2 inhibition also hampered cAMP-dependent induction of UCP1, PGC1a, and other browning marker genes, and thermogenic induction of these genes was potentiated by thiamine in a concentration dependent manner. Our study reveals the importance of amply supplied thiamine during thermogenic activation in human adipocytes which provides TPP for TPP-dependent enzymes not fully saturated with this cofactor and by potentiating the induction of thermogenic genes.

The prevalence of thiamine deficiency among elderly nursing home residents: A cross-sectional study

Background

Although thiamine deficiency (TD) can lead to Wernicke encephalopathy, the characteristics associated with TD in the elderly have not yet been clarified. We sought to clarify the frequency of TD among an institutionalized elderly population with a controlled dietary intake and to identify possible factors related to TD.

Method

We undertook a cross-sectional study of residents in three nursing homes for the elderly as of June 2020. Blood thiamine concentrations were measured using a high-performance liquid chromatography method, with TD defined as a concentration of <21.3 ng/mL. Basic data (age, sex, height, weight, and BMI), dietary intake for the previous 3 weeks, degree of care (DOC), degree of independence in daily life for elderly with dementia (DIDLED), and comorbidities were analyzed using descriptive statistical methods.

Results

The mean age (±SD) was 86.9 years (±8.29), with 84 residents (70.0%) being female. The DIDLED varied from total independence to long-term care level 5 (full assistance), with 89.2% suffering dementia. The mean whole blood thiamine value was 36.18 (±17.58) ng/ml, with TD confirmed in 7 (5.8%) of the 120 residents. All TD patients suffered from dementia. No TD was observed in patients with a near-normal food intake, and no related factors were observed among the other items.

Conclusion

Reduced food intake may at increase the risk of TD and symptoms of TD may be overlooked in those displaying symptoms of dementia; thus, it is important for clinicians working with the elderly to remain aware of the potential for TD.

Does thiamine supplementation affect heart failure? A systematic review and meta-analysis of randomized control trials

BACKGROUND

Heart failure is a pathophysiological condition where decreased cardiac output is observed subsequent to any structural deformity or cessation of normal function. Thiamine deficiency is one of the risk factors responsible for causing HF; other risk factors include hypertension, smoking, and obesity.

OBJECTIVE

We conducted a systemic review and meta-analysis of RCTs to scrutinize whether the heart failure patients would benefit from thiamine supplementation or not when compared to placebo.

METHODS

We selected only those double-arm randomized controlled trials (RCTs) which included participants presenting with symptomatic heart failure. We excluded all the articles published in languages other than English Language. Furthermore, all the studies other than RCTs were also omitted. Articles yielded from the electronic search were exported to EndNote Reference Library software to remove any duplicates. Analyses were done using the Review manager 5.4 tool. Mean values and standard deviations were retrieved for the continuous outcomes given as raw data.

RESULTS

The 6 RCTs selected for the statistical analysis consisted of 298 participants (158 in the intervention group, 140 in the placebo group). The outcomes resulted to be non-significant with LVEF p-value= 0.08, NT-pro BNP p-value= 0.94, LVEDV p-value= 0.53, 6MWT p-value=0.59, mortality p-value= 0.61, hospitalization p-value= 0.53 and dyspnea p-value= 0.77. Heart rate is the only significant outcome with a p-value=0.04.

CONCLUSION

To conclude, except for heart rate, thiamine supplementation had no effect on the outcomes of heart failure patients.

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.

Pulmonary artery catheter usage in diagnosis of Shoshin beriberi presented with unexplained lactic acidosis

Wet beriberi is a rare but fatal disease in modern society. The nonspecific clinical manifestations, including symptoms of heart failure and recalcitrant lactic acidosis, can prevent timely diagnosis. The use of a pulmonary artery catheter can promptly confirm a high cardiac output state and plays a crucial role in rapidly deteriorating cases. Appropriate treatment with intravenous administration of thiamine leads to dramatic recovery within hours. We present two cases of Shoshin beriberi, a fulminant variant of wet beriberi, diagnosed in 2016 and 2022 at our institute. The patients experienced haemodynamic collapse and refractory lactic acidosis, which were successfully diagnosed with the use of a pulmonary artery catheter and reversed by thiamine supplementation. We also reviewed 19 cases of wet beriberi reported between 2010 and 2022.

Carrot and carotene and multiple health outcomes: an umbrella review of the evidence

In recent years, the benefits of carrots and carotene in different areas of health have been examined. The purpose of this umbrella review was to identify the associations between carrots and carotene and multiple health outcomes. The review considered evidence from meta-analyses of interventional and observational studies of carrots and carotene and any health outcome. We comprehensively searched Web of Science, PubMed, and Embase. For each association, we estimated the summary effect size using random and fixed effects models and the 95% confidence interval. A total of 1329 studies were searched, and 30 meta-analyses with 26 health outcomes were identified that met the eligibility criteria. Carrot intake was associated with a lower risk of multiple cancer outcomes including breast cancer, lung cancer, pancreatic cancer, gastric cancer, urothelial cancer, and prostate cancer. Carotene intake was associated with a lower risk of fracture, age-related cataract, sunburn, Alzheimer's disease, breast cancer, lung cancer, pancreatic cancer, gastric cancer, esophageal cancer, prostate cancer, and head and neck cancer (HNC). Serum carotene was inversely associated with all-cause mortality, breast cancer, and lung cancer. Our study revealed that carrot or carotene intake could reduce the risk of various negative health outcomes. © 2023 Society of Chemical Industry.

Protocol and application of basal erythrocyte transketolase activity to improve assessment of thiamine status

Thiamine (vitamin B1) is an essential micronutrient required as a cofactor in many metabolic processes. Clinical symptoms of thiamine deficiency are poorly defined, hence biomarkers of thiamine status are important. The erythrocyte transketolase activity coefficient (ETKac) is a sensitive measure of thiamine status, but its interpretation may be confounded where the availability of the transketolase enzyme is limited. Basal ETK activity per gram of hemoglobin provides a complementary biomarker of thiamine status; however, its measurement and calculation are poorly described. Here, we describe in detail the assessment of basal ETK activity, including the calculation of path length in microplates and the molar absorption coefficient of NADH specific to the assay, and the measurement of hemoglobin in sample hemolysates. To illustrate the application of the methods, we present ETKac and basal ETK activity from women in The Gambia and UK. In conclusion, we present a clear protocol for the measurement of basal ETK activity that will permit the harmonization of methods to improve replication between laboratories.

Thiamine Supplementation Improves Survival and Body Condition of Hatchery-Reared Steelhead (Oncorhynchus mykiss) in Oregon

Early rearing of steelhead (Oncorhynchus mykiss) in Oregon hatcheries is often problematic; fry can become emaciated and die during the period between hatch and first feed. Thiamine (vitamin B1) deficiency has caused early mortality in salmonids; however, the thiamine status of Oregon's steelhead populations is unknown, to date. Of the 26 egg samples from three Oregon hatcheries in 2019, 20 (77%) had thiamine levels < 10 nmol/g, and 13 of those samples (50%) had levels <6.5 nmol/g, suggesting the thiamine deficiency of adult, female steelhead. To investigate if thiamine deficiency was causally related to fry survival, females were injected with buffered thiamine HCl 50 mg/kg prior to spawning; additionally, a subset of eggs were supplemented via bath treatment with thiamine mononitrate (1000 ppm) at spawning. Cumulative fry mortality at 8 weeks post-hatch from thiamine-injected females was 2.9% compared to 13.8% mortality of fry without thiamine supplementation. Fry treated only with the thiamine via bath as eggs had a mortality rate of 6.9%. There were no additional improvements for the survival of fry from injected females that also received a thiamine bath. Furthermore, condition factors were greater in thiamine-supplemented fry than in those that received no thiamine. These data identify thiamine deficiency in Oregon steelhead and suggest supplementation with thiamine can mitigate early rearing mortality.

Maternal preconception circulating blood biomarker mixtures, child behavioural symptom scores and the potential mediating role of neonatal brain microstructure: the S-PRESTO cohort

Human brain development starts in the embryonic period. Maternal preconception nutrition and nutrient availability to the embryo may influence brain development at this critical period following conception and early cellular differentiation, thereby affecting offspring neurodevelopmental and behavioural disorder risk. However, studying this is challenging due to difficulties in characterizing preconception nutritional status and few studies have objective neurodevelopmental imaging measures in children. We investigated the associations of maternal preconception circulating blood nutrient-related biomarker mixtures (~15 weeks before conception) with child behavioural symptoms (Child Behaviour Checklist (CBCL), aged 3 years) within the Singapore Preconception Study of Long-Term Maternal and Child Outcomes (S-PRESTO) study. The CBCL preschool form evaluates child behaviours based on syndrome scales and Diagnostic and Statistical Manual of Mental Disorders (DSM) oriented scales. These scales consist of internalizing problems, externalizing problems, anxiety problems, pervasive developmental problems, oppositional defiant, etc. We applied data-driven clustering and a method for modelling mixtures (Bayesian kernel machine regression, BKMR) to account for complex, non-linear dependencies between 67 biomarkers. We used effect decomposition analyses to explore the potential mediating role of neonatal (week 1) brain microstructure, specifically orientation dispersion indices (ODI) of 49 cortical and subcortical grey matter regions. We found that higher levels of a nutrient cluster including thiamine, thiamine monophosphate (TMP), pyridoxal phosphate, pyridoxic acid, and pyridoxal were associated with a higher CBCL score for internalizing problems (posterior inclusion probability (PIP) = 0.768). Specifically, thiamine independently influenced CBCL (Conditional PIP = 0.775). Higher maternal preconception thiamine level was also associated with a lower right subthalamic nucleus ODI (P-value = 0.01) while a lower right subthalamic nucleus ODI was associated with higher CBCL scores for multiple domains (P-value < 0.05). One potential mechanism is the suboptimal metabolism of free thiamine to active vitamin B1, but additional follow-up and replication studies in other cohorts are needed.