Thiamin deficiency and heart failure: the current knowledge and gaps in literature

The Association Between Vitamin B1 Deficiency and Anemia Among Elderly Patients at a Rural Hospital in Japan: A Cross-Sectional Study

Background and objective Vitamin B1 deficiency can cause a variety of abnormalities in the neuropsychiatric, cardiovascular, and other systems. This condition can be rapidly corrected and prevented from progressing to irreversible sequelae through vitamin B1 supplementation. Therefore, early detection of and intervention in vitamin B1 deficiency are essential. We have previously demonstrated an association between vitamin B1 deficiency and appetite loss in hospitalized older adult patients in rural Japan. This study aimed to examine the additional predictors of vitamin B1 deficiency in patients with appetite loss and other symptoms suggestive of vitamin B1 deficiency. Material and methods This cross-sectional study involved 519 patients admitted to a rural hospital between April 2020 and March 2022. Data on vitamin B1 levels, age, sex, BMI, albumin levels, functional independence measure (FIM), hemoglobin levels, Charlson Comorbidity Index (CCI), and medications were collected from electronic medical records. Vitamin B1 deficiency was defined as serum vitamin B1 level <20 µg/dL. Data were analyzed using the Mann-Whitney U test, Student's t-test, and chi-square test, followed by multivariate logistic regression to examine the predictors of vitamin B1 deficiency. Results A total of 113 patients (21.5%) were found to be vitamin B1-deficient. Multivariate logistic regression showed that anemia was significantly associated with vitamin B1 deficiency [adjusted odds ratio (AOR): 1.71, 95% confidence interval (CI): 1.07-2.73, p<0.05]. Conclusion Based on our findings, anemia is significantly associated with vitamin B1 deficiency in hospitalized Japanese patients living in rural areas. Therefore, physicians should be mindful of the possibility of vitamin B1 deficiency in hospitalized patients with anemia.

Association of vitamin B1 with cardiovascular diseases, all-cause and cardiovascular mortality in US adults

Background

The correlation between dietary vitamin B1 intake and cardiovascular diseases, as well as the all-cause and cardiovascular-associated mortality, is not well known. A large-scale data pool was used to examine the aforementioned correlations of Vitamin B1.

Methods

This paper analyzed the dietary data from the survey conducted by National Health and Nutrition Examination (NHANES; 1999-2018). The correlation of vitamin B1 intake in each quartile with cardiovascular diseases such as hypertension, coronary heart disease, myocardial infarction and heart failure was analyzed using multivariate logistic regression models. The hazard ratios for dietary vitamin B1 intake in each quartile, along with all-cause and cardiovascular-associated mortality, were performed using multivariate cox regression analysis, setting the lowest quartile (Q1) as a reference. The restricted cubic spline (RCS) method was used to study the nonlinear relationship. Subgroup stratification and sensitivity analyses were used to further investigate the association between them.

Results

The study enrolled 27,958 subjects (with a mean follow-up time of 9.11 years). After multivariate adjustment, dietary vitamin B1 intake was significantly associated with hypertension, heart failure and cardiovascular mortality, with the most significant association in quartile 4 (Q4) of vitamin B1 intake. The results of the restricted cubic spline showed that vitamin B1 intake was nonlinearly associated with hypertension, whereas it was linearly associated with heart failure and cardiovascular mortality. Meanwhile, a dose-response correlation was observed, indicating that increased vitamin B1 intake leads to reduced risk of both cardiovascular prevalence and mortality. The stratified analysis showed that the correlation between age ≥ 50 years, overweight, smoking history, drinking history and dyslipidemia were more significant in male patients. The associations remained similar in the sensitivity analyses.

Conclusion

The large NHANES-based studies indicate a gradual trend toward decreasing the risk of hypertension and heart failure prevalence and cardiovascular mortality with increasing dietary vitamin B1 intake. This association is especially significant in elderly-aged men, overweight individuals, smokers, drinkers, and dyslipidemia patients.

Causal effects of circulating vitamin levels on the risk of heart failure: a Mendelian randomization study

BACKGROUND

Observational studies suggest inverse associations between serum vitamin levels and the risk of heart failure (HF). However, the causal effects of vitamins on HF have not been fully elucidated. Here, we conducted a Mendelian randomization (MR) study to investigate the causal associations between genetically determined vitamin levels and HF.

METHODS

Genetic instrumental variables for circulating vitamin levels, including vitamins A, B, C, D, and E, which were assessed as either absolute or metabolite levels were obtained from public genome-wide association studies. Summary statistics for single-nucleotide-polymorphisms and HF associations were retrieved from the HERMES Consortium (47,309 cases and 930,014 controls) and FinnGen Study (30,098 cases and 229,612 controls). Two-sample MR analyses were implemented to assess the causality between vitamin levels and HF per outcome database, and the results were subsequently combined by meta-analysis.

RESULTS

Our MR study did not find significant associations between genetically determined circulating vitamin levels and HF risk. For absolute vitamin levels, the odds ratio for HF ranged from 0.97 (95% confidence interval [CI]: 0.85-1.09, P = 0.41) for vitamin C to 1.05 (95% CI: 0.61-1.82, P = 0.85) for vitamin A. For vitamin metabolites, the odds ratio ranged between 0.94 (95% CI: 0.75-1.19, P = 0.62) for α-tocopherol and 1.11 (95% CI: 0.98-1.26, P = 0.09) for γ-tocopherol.

CONCLUSION

Evidence from our study does not support the causal effects of circulating vitamin levels on HF. Therefore, there may be no direct beneficial effects of vitamin intake on the prevention of primary HF.

Thiamine status during treatment of diabetic ketoacidosis in children - tertiary care centre experience

OBJECTIVES

There is a lack of information regarding thiamine status in children with diabetic ketoacidosis (DKA). This study was designed to assess the thiamine status upon admission and 24 h after treatment initiation of DKA, whether newly diagnosed children or with established T1DM diagnosis, who presented with DKA.

METHODS

We enrolled 90 children (mean age, 9.8 ± 2.6 years; 58 females and 32 males) with type 1 diabetes mellitus (T1DM), whether newly diagnosed or with an established T1DM diagnosis (from 1 to 5.2 years ago), who presented with DKA. We observed the initial Glasgow Coma Scale (GCS) and recovery time. The whole blood thiamine diphosphate levels were measured upon admission (baseline point) and 24 h after initiation of the DKA treatment (second-time point).

RESULTS

The mean blood thiamine levels at the second-time point (90.11 ± 15.76 nmol/L) significantly decreased compared with their levels at baseline (108.8 ± 17.6 nmol/L) (p<0.001). We compared thiamine levels with the initial GCS, patient's age, and recovery time. Thiamine levels at the second-time point were positively correlated with baseline thiamine levels (r=0.86, p=0.0001) and the initial GCS (r=0.68, p=0.001) but were negatively correlated with patient's age (r=-0.61, p=0.001) and recovery time (r=-0.724, p=0.001). Based on multiple regression analysis, thiamine levels at the second-time point were directly related to the initial GCS and inversely related to the patient's age.

CONCLUSIONS

The current study indicates that blood thiamine diphosphate levels significantly decreased after 24 h of DKA treatment initiation compared to pre-treatment levels. After 24 h of treatment initiation, blood thiamine levels are directly related to the initial GCS and inversely related to the patient's age.

Vitamin B1 Deficiency and Perimyocarditis Fulminans: A Case Study of Shoshin Syndrome in a Woman Following an Unbalanced Dietary Pattern Followed by a Literature Review

(1) Background: vitamin B1 level depletion, known as a beriberi syndrome, can lead to severe cardiovascular complications, from which perimyocarditis fulminans is one of the most severe. (2) Methods: this is a retrospective case study that includes an adult patient with clinical presentations of acute heart failure (HF) symptoms following perimyocarditis on the grounds of thiamine deficiency. (3) Results: A 49-year-old woman presented with acute HF symptoms due to perimyocarditis. The patient suddenly developed refractory cardiogenic shock with metabolic acidosis requiring maximal medical management, including an intra-aortic balloon pump and extracorporeal membrane oxygenation. Due to additional peripheral polyneuropathy, beriberi disease was suspected after excluding other possible causes of the patient's condition. After administration of vitamin B1, clinical improvement in the patient's condition and the resolution of metabolic abnormalities were observed, which ultimately confirmed the diagnosis of Shoshin syndrome caused by the implementation of a gluten-free diet without indications for its adherence. (4) Conclusions: Fulminant beriberi disease, although considered rare, is a life-threatening condition and should always be included in the differential diagnosis of critically ill patients, notably those with malnutrition. An unbalanced diet can be detrimental and have severe consequences, i.e., perimyocarditis fulminans. However, treatment with thiamine can significantly improve the patient's cardiac function and restore hemodynamic and metabolic parameters.

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.

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.

Evaluation of blood thiamine concentration in hospitalized dogs with and without critical illness

OBJECTIVE

To evaluate blood thiamine concentration in healthy and critically ill hospitalized dogs over 72 hours of hospitalization and to identify any association of thiamine concentration with patient morbidity and mortality.

DESIGN

Prospective, observational, clinical study.

SETTING

University veterinary teaching hospital.

ANIMALS

Thirty-one hospitalized healthy dogs and 37 dogs with critical illness. Dogs with critical illness had nonseptic (n = 24) or septic (n = 13) etiologies.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Whole blood EDTA samples were collected within 24 hours of admission and 72 hours later. Samples were stored at -80°C and batch analyzed. Total thiamine (tB1) and thiamine diphosphate (TDP) concentrations were measured using high-performance liquid chromatography, and free thiamine concentration was determined using liquid chromatography with tandem mass spectrometry. Collected patient data included CBC, biochemistry profile, plasma lactate concentration, shock index, Acute Patient Physiologic and Laboratory Evaluation Score (APPLE_fast ) score, comorbid conditions, and patient outcome. Approximately 92% of tB1 present in whole blood is measured as TDP. TDP concentration was strongly correlated with tB1 (R = 0.97, P < 0.0001). Thiamine concentration, represented by TDP, was not different at admission or at 72 hours in all dogs. TDP concentration was lower in septic dogs requiring surgery at admission (P = 0.044) and 72 hours later (P = 0.008), compared to dogs not requiring surgery. TDP concentration was not different between dogs with and without stable chronic diseases at any time point. Older dogs had lower TDP concentration. Positive correlations were seen between TDP and body weight, APPLE_fast score, and WBC count. Critically ill dogs with lower admission plasma lactate concentration were more likely to have an increase in thiamine over time (P = 0.0142).

CONCLUSIONS

Differences in thiamine concentration were not identified in hospitalized healthy or critically ill dogs. Further investigation into the clinical relevance of thiamine deficiency is indicated in septic dogs undergoing surgery.

Metabolic Therapy of Heart Failure: Is There a Future for B Vitamins?

Heart failure (HF) is a plague of the aging population in industrialized countries that continues to cause many deaths despite intensive research into more effective treatments. Although the therapeutic arsenal to face heart failure has been expanding, the relatively short life expectancy of HF patients is pushing towards novel therapeutic strategies. Heart failure is associated with drastic metabolic disorders, including severe myocardial mitochondrial dysfunction and systemic nutrient deprivation secondary to severe cardiac dysfunction. To date, no effective therapy has been developed to restore the cardiac energy metabolism of the failing myocardium, mainly due to the metabolic complexity and intertwining of the involved processes. Recent years have witnessed a growing scientific interest in natural molecules that play a pivotal role in energy metabolism with promising therapeutic effects against heart failure. Among these molecules, B vitamins are a class of water soluble vitamins that are directly involved in energy metabolism and are of particular interest since they are intimately linked to energy metabolism and HF patients are often B vitamin deficient. This review aims at assessing the value of B vitamin supplementation in the treatment of heart failure.

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.

Association between transient appetite loss and vitamin B1 deficiency in elderly patients with suspected deficiency

BACKGROUND

There is scarce evidence associating vitamin B1 levels and appetite loss duration in elderly patients with suspected B1 deficiency. We aimed to investigate this association in elderly hospitalized patients with suspected vitamin B1 deficiency in rural Japan.

METHODS

This cross-sectional study evaluated 309 elderly patients (aged ≥ 65 years) admitted to one rural Hospital between April 2017 and March 2019. We collected data on vitamin B1 level, age, sex, body mass index, albumin levels, area of residence, long-term care, dependent conditions, activities of daily living, Charlson comorbidity index, and appetite loss from the patients' electronic medical records. Vitamin B1 deficiency was defined as serum vitamin B1 levels <20 μg/dL. Data were analyzed using the Mann-Whitney U, Student's t, and chi-square tests, followed by multivariable logistic regression, to examine the association between vitamin B1 deficiency and appetite loss.

RESULTS

Eighty-eight (28.5%) patients had vitamin B1 deficiency. In multivariable logistic regression, appetite loss (for both < 1 and > 1 week) before admission to the hospital showed a significant association with vitamin B1 deficiency (adjusted odds ratio [AOR] =10.80, 95% confidence interval [CI]: 5.16-22.00, P < .001; and AOR = 5.77, 95% CI: 2.88-11.50, P < .001, respectively).

CONCLUSIONS

Appetite loss is associated with vitamin B1 deficiency in elderly Japanese patients living in rural areas. Therefore, physicians should be aware of the possibility of vitamin B1 deficiency in elderly patients with appetite loss and focus on early intervention.

A BERIBERI UNHEALTHY LATTE: ENCEPHALOPATHY AND SHOCK FROM SEVERE NUTRITIONAL DEFICIENCY

BACKGROUND

Thiamine deficiency is an uncommon cause of severe illness in the United States that can lead to significant morbidity because of high-output cardiac failure, peripheral neuropathy, and permanent neurologic impairment. We report the case of a middle-aged woman with extreme malnutrition caused by complications of Roux-en-Y gastric bypass (RYGB) surgery who presented with signs and symptoms of severe thiamine deficiency and septic shock.

CASE REPORT

A 43-year-old woman who had undergone RYGB surgery and who had multiple complications presented to the emergency department with agitation, confusion, and lethargy. The physical examination revealed an obtunded woman appearing much older than her reported age with significant peripheral edema. She was hypoxemic, hypotensive, and febrile. The initial laboratory analysis revealed a serum lactate level above the measurable limit, a normal thyroid-stimulating hormone, and elevated levels of troponin and brain natriuretic peptide. A transthoracic echocardiogram showed high-output heart failure. The patient's family later revealed that for the past year her diet had consisted almost exclusively of frozen blended lattes. High doses of thiamine and folate were started. Her shock, hyperlactatemia, and respiratory failure resolved by hospital day 3 and her encephalopathy resolved soon thereafter. Why Should an Emergency Physician be Aware of This?: Thiamine deficiency is a rare but reversible cause of shock, heart failure, and encephalopathy. Identifying patients who are at risk for severe nutritional deficiencies may aid in more rapid treatment with relatively benign medications with little downside, in this case high-dose vitamin B₁, and ultimately improve patient-oriented outcomes such as mortality, morbidity, and hospital length of stay.

Thiamine Deficiency Causes Long-Lasting Neurobehavioral Deficits in Mice

Thiamine deficiency (TD) has detrimental effects on brain health and neurobehavioral development, and it is associated with many aging-related neurological disorders. To facilitate TD-related neuropsychological studies, we generated a TD mouse model by feeding a thiamine-deficient diet for 30 days, followed by re-feeding the control diet for either one week or 16 weeks as recovery treatment. We then performed neurobehavioral tests in these two cohorts: cohort of one week post TD treatment (1 wk-PTDT) and 16 weeks post TD treatment (16 wks-PTDT). The TD mice showed no significant difference from control in any tests in the 1 wk-PTDT cohort at the age of 13-14 weeks. The tests for the 16 wks-PTDT cohort at the age of 28-29 weeks, however, demonstrated anxiety and reduced locomotion in TD animals in open field and elevated plus maze. In comparison, rotor rod and water maze revealed no differences between TD and control mice. The current findings of the differential effects of the same TD treatment on locomotion and anxiety at different ages may reflect the progressive and moderate change of TD-induced neurobehavioral effects. The study suggests that, even though the immediate neurobehavioral impact of TD is modest or negligible at a young age, the impact could develop and become severe during the aging process.

Possible involvement of thiamine insufficiency in heart failure in the institutionalized elderly

Heart failure is a major manifestation of thiamine deficiency; beriberi. Even thiamine insufficiency, milder than deficiency, may be associated with increased heart failure risk. In this cross-sectional study, the relationship between thiamine insufficiency and heart failure was investigated in the Japanese institutionalized elderly from April to November 2017. Fifty-five subjects in four care facilities were evaluated for their whole blood thiamine and plasma brain natriuretic peptide concentrations. Mean whole blood thiamine concentration was 88.7 ± 22.3 nmol/L in men and 92.0 ± 16.5 nmol/L in women, and significantly and negatively correlated with plasma brain natriuretic peptide concentrations (r = −0.378, p = 0.007). In the multiple regression analysis adjusted by age, sex, body mass index, and eGFR, whole blood thiamine concentration was a significant negative contributor (standardized coefficient β = −0.488, p = 0.001) to plasma brain natriuretic peptide. In the logistic regression analysis adjusted by the same variables, whole blood thiamine concentration significantly contributed to plasma brain natriuretic peptide concentration higher than over 40 pg/ml (OR: 0.898, 95%CI: 0.838–0.962). Whole blood thiamine concentration in subjects with diuretics was significantly lower than those without it (p = 0.023). Thiamine insufficiency was related to increased plasma brain natriuretic peptide concentration and may increase the risk of heart failure.

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.

Prevalence of Thiamin Deficiency in Ambulatory Patients with Heart Failure

BACKGROUND

Thiamin is a required coenzyme in energy production reactions that fuel myocardial contraction. Therefore, thiamin deficiency (TD) may aggravate cardiac dysfunction in patients with systolic heart failure (HF).

OBJECTIVE

To determine the prevalence of TD in ambulatory participants with HF as well as the relationships between thiamin status and HF severity, dietary thiamin intake, diuretic use, and circulating neurohormones.

DESIGN

A cross-sectional study comparing the prevalence of TD in ambulatory patients with HF with that of controls. Demographic, anthropometric, nutrition, medication use, and heart function data were collected from direct interviewing, questionnaires, and medical records. Blood samples were obtained to measure levels of neurohormones and assess TD.

PARTICIPANTS/SETTING

Fifty age-matched control participants without HF and 100 outpatients with HF and reduced left ventricular function were recruited from clinics at St Michael's Hospital, University Health Network and Mount Sinai Hospital, Toronto, Ontario, Canada, between September 2009 and February 2011.

MAIN OUTCOME MEASURES

To assess TD, erythrocyte thiamin pyrophosphate (TPP) was measured using high-performance liquid chromatography. TD was defined as TPP<6.07 μg/dL (180 nmol/L).

STATISTICAL ANALYSES PERFORMED

Prevalence rates were analyzed using χ² test. Nonparametric statistics (Jonckheere-Terpstra, Kruskal-Wallis, Spearman's correlation) were used to assess TPP levels in relation to HF severity, medication use and plasma concentrations of F2-isoprostanes, norepinephrine, and N-terminal pro-brain natriuretic peptide (NT-proBNP).

RESULTS

There was no significant difference in the prevalence of TD in outpatients with HF (6%) and controls (6%) (P=0.99). No relationship was found between heart function, thiamin intake, use or dose of diuretics, and TD. A positive relationship was observed between erythrocyte TPP and F2-isoprostane levels (r_s=0.22, P=0.03) but not between erythrocyte TPP and norepinephrine (P=0.45) and NT-proBNP (P=0.58).

CONCLUSION

The prevalence of TD was low in ambulatory HF participants suggesting that, unlike hospitalized patients, ambulatory patients may be at a low risk for TD.

A novel LC-MS/MS assay for vitamin B1, B2 and B6 determination in dried blood spots and its application in children

Thiamin, riboflavin and pyridoxal phosphate (PLP) concentrations are useful indices for evaluating vitamin B₁, B₂ and B₆ status. Several HPLC assays have been developed for determining thiamin, riboflavin and PLP in biological matrix. However, no existing LC-MS/MS methods can be used to quantify thiamin, riboflavin and PLP in dried blood spots (DBSs), which are often used as a sampling/storage vessel for blood from infants and children. This study evaluated the validity, reliability and stability of an LC-MS/MS assay for measuring thiamin, riboflavin and PLP in DBS cards. DBS samples were deproteinized by adding trichloroacetic acid containing thiamine-[¹³C₄], riboflavin-[¹³C₄,¹⁵N₂] and pyridoxal-d₃ as internal standards. Thiamin, riboflavin and PLP were separated on a C8 column with a 5-min run time. Both the between-run and within-run variable coefficients (CV% values) were < 8.56%. The accuracies were good and showed relative errors (RE% values) from -7.40% to 3.12%. The lower limits of quantification (LLOQs) ranged from 0.2 to 0.5 ng/mL, and the recoveries were from 81.49% to 112.23% for all 3 analytes. The matrix effects (ME% values) were acceptable, and the CV% values of the internal standard-normalized matrix factors were <15% (n = 6). Thiamin, riboflavin and PLP were stable on the DBS card during at least 15 days of room-temperature storage under vacuum in the dark, and the measurements of thiamin, riboflavin and PLP in the DBSs showed good agreement with the corresponding concentrations determined from liquid blood (R² values >0.96). The validated method was successfully applied to the nutritional assessment of vitamins B₁, B₂, and B₆ in 48 Chinese children.

The Role of Thiamine and Effects of Deficiency in Dogs and Cats

Recent pet food recalls for insufficient dietary thiamine have highlighted the importance of adequate thiamine intake in dogs and cats, as thiamine is an essential dietary nutrient with a critical role in energy metabolism. Prolonged thiamine deficiency leads to clinical signs that can span several organ systems, and deficiency can be fatal if not reversed. In this review, the current knowledge of thiamine metabolism will be summarized. Dietary recommendations for dogs and cats will be discussed, and the risk factors and clinical signs associated with thiamine deficiency will be examined.

Vitamin B1 in critically ill patients: needs and challenges

BACKGROUND

Thiamine has a crucial role in energy production, and consequently thiamine deficiency (TD) has been associated with cardiac failure, neurological disorders, oxidative stress (lactic acidosis and sepsis) and refeeding syndrome (RFS). This review aims to explore analytical methodologies of thiamine compound quantification and highlight similarities, variances and limitations of current techniques and how they may be relevant to patients.

CONTENT

An electronic search of Medline, PubMed and Embase databases for original articles published in peer-reviewed journals was conducted. MethodsNow was used to search for published analytical methods of thiamine compounds. Keywords for all databases included "thiamine and its phosphate esters", "thiamine methodology" and terms related to critical illness. Enquiries were also made to six external quality assurance (EQA) programme organisations for the inclusion of thiamine measurement.

SUMMARY

A total of 777 published articles were identified; 122 were included in this review. The most common published method is HPLC with florescence detection. Two of the six EQA organisations include a thiamine measurement programme, both measuring only whole-blood thiamine pyrophosphate (TPP). No standard measurement procedure for thiamine compound quantification was identified.

OUTLOOK

Overall, there is an absence of standardisation in measurement methodologies for thiamine in clinical care. Consequently, multiple variations in method practises are prohibiting the comparison of study results as they are not traceable to any higher order reference. Traceability of certified reference materials and reference measurement procedures is needed to provide an anchor to create the link between studies and help bring consensus on the clinical importance of thiamine.

Thiamine Assays-Advances, Challenges, and Caveats

Thiamine (vitamin B1) is essential to the health of all living organisms and deficiency has long been associated with diseases in animals such as fish, birds, alligators, and domesticated ruminant mammals. Thiamine is also implicated in several human diseases including Alzheimer's, diabetes, dementia, depression and, most notably, Wernicke-Korsakoff syndrome and Beriberi disease. Yet, highly sensitive and specific detection of thiamine remains an analytical challenge, as pM to nm levels of thiamine need to be detected in environmental and human samples, respectively, various phosphorylated variants need to be discriminated, and rapid on-site detection would be highly desirable. Furthermore, appropriate sample preparation is mandatory, owing to the complexity of the relevant sample matrices including fish tissues, ocean water, and body fluids. This Review has two objectives. First, it provides a thorough overview of analytical techniques published for thiamine detection over the last 15 years. Second, it describes the principles of analytical approaches that are based on biorecognition and may open up new avenues for rapid and high-throughput thiamine analysis. Most notably, periplasmic binding proteins, ribozymes, and aptamers are of particular interest, as they function as bioaffinity recognition elements that can fill an important assay technology gap, owing to the unavailability of thiamine-specific commercial antibodies. Finally, the authors provide brief evaluations of key outcomes of the major assay concepts and suggest how innovative techniques could help develop sensitive and specific thiamine analytical test systems.

Thiamine Deficiency and Neurodegeneration: the Interplay Among Oxidative Stress, Endoplasmic Reticulum Stress, and Autophagy

Thiamine (vitamin B1) is an essential nutrient and indispensable for normal growth and development of the organism due to its multilateral participation in key biochemical and physiological processes. Humans must obtain thiamine from their diet since it is synthesized only in bacteria, fungi, and plants. Thiamine deficiency (TD) can result from inadequate intake, increased requirement, excessive deletion, and chronic alcohol consumption. TD affects multiple organ systems, including the cardiovascular, muscular, gastrointestinal, and central and peripheral nervous systems. In the brain, TD causes a cascade of events including mild impairment of oxidative metabolism, neuroinflammation, and neurodegeneration, which are commonly observed in neurodegenerative diseases, such as Alzheimer's disease (AD), Parkinson's disease (PD), and Huntington's disease (HD). Thiamine metabolites may serve as promising biomarkers for neurodegenerative diseases, and thiamine supplementations exhibit therapeutic potential for patients of some neurodegenerative diseases. Experimental TD has been used to model aging-related neurodegenerative diseases. However, to date, the cellular and molecular mechanisms underlying TD-induced neurodegeneration are not clear. Recent research evidence indicates that TD causes oxidative stress, endoplasmic reticulum (ER) stress, and autophagy in the brain, which are known to contribute to the pathogenesis of various neurodegenerative diseases. In this review, we discuss the role of oxidative stress, ER stress, and autophagy in TD-mediated neurodegeneration. We propose that it is the interplay of oxidative stress, ER stress, and autophagy that contributes to TD-mediated neurodegeneration.

Can long-term thiamine treatment improve the clinical outcomes of myotonic dystrophy type 1?

Myotonic dystrophy type 1, also known as Steinert's disease, is an autosomal dominant disorder with multisystemic clinical features affecting the skeletal and cardiac muscles, the eyes, and the endocrine system. Thiamine (vitamin B1) is a cofactor of fundamental enzymes involved in the energetic cell metabolism; recent studies described its role in oxidative stress, protein processing, peroxisomal function, and gene expression. Thiamine deficiency is critical mainly in the central and peripheral nervous system, as well as in the muscular cells. Our aim was to investigate the potential therapeutical effects of long-term treatment with thiamine in myotonic dystrophy type 1 in an observational open-label pilot study. We described two patients with myotonic dystrophy type 1 treated with intramuscular thiamine 100 mg twice a week for 12 or 11 months. We evaluated the patients using the grading of muscle strength according to Medical Research Council (MRC), the Muscular Impairment Rating Scale (MIRS), and the Modified Barthel index. High-dose thiamine treatment was well tolerated and effective in improving the motor symptomatology, particularly the muscle strength evaluated with the MRC scale, and the patients' activities of daily living using the Modified Barthel Index. At the end of treatment, the MRC score was 5 in the proximal muscles and 2-4 in the distal muscles (the MRC score before the treatment was 3-4 and 1-3, respectively). The MIRS grade improved by 25% compared to baseline for both patients. In patient #1, the Modified Barthel Index improved by 44%, and in patient #2 by 29%. These findings suggest that clinical outcomes are improved by long-term thiamine treatment.