Thiamine deficiency in Cambodian infants with and without beriberi

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.

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.

Thiamine deficiency disorders in women and children

Thiamine (vitamin B1) is available in common foods such as the outer husk of rice and is necessary for normal cardiovascular, neurological and metabolic processes. Thiamine deficiency is common in many parts of Asia and Africa, affecting up to a third or more of children and women of child-bearing age. The diagnosis is based on clinical suspicion, especially when noting heart failure in infants, encephalopathy in patients of any age, and peripheral neuropathy in older children and adults. Blood tests for whole-blood thiamine diphosphate (the quantity of biologically active thiamine present) and erythrocyte transketolase activity (the functional impact of thiamine) are not always readily available in areas where thiamine deficiency is common. Treatment is safe and effective, although dosing guidelines vary widely; 50 mg daily for 5 days is probably effective for treating acute thiamine deficiency disorders, and ongoing adequate thiamine intake is also needed. Prevention efforts depend on local and regional circumstances, including dietary diversification, food fortification, and/or supplementation of children and women at risk.Abbreviations: HIC: high-income countries; LMIC: low- and middle-income countries; MRI: magnetic resonance imaging; TDD: thiamine deficiency disorders.

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.

Furan-based inhibitors of pyruvate dehydrogenase: SAR study, biochemical evaluation and computational analysis

Suppression of pyruvate dehydrogenase complex (PDHc) is a mechanism for cancer cells to manifest the Warburg effect. However, recent evidence suggests that whether PDHc activity is suppressed or activated depends on the type of cancer. The PDHc E1 subunit (PDH E1) is a thiamine pyrophosphate (TPP)-dependent enzyme, catalysing the first and rate-limiting step of PDHc; thus, there is a need for selective PDH E1 inhibitors. There is, however, inadequate understanding of the structure-activity relationship (SAR) and a lack of inhibitors specific for mammalian PDH E1. Our group have reported TPP analogues as TPP-competitive inhibitors to study the family of TPP-dependent enzymes. Most of these TPP analogues cannot be used to study PDHc in cells because (a) they inhibit all members of the family and (b) they are membrane-impermeable. Here we report derivatives of thiamine/TPP analogues that identify elements distinctive to PDH E1 for selectivity. Based on our SAR findings, we developed a series of furan-based thiamine analogues as potent, selective and membrane-permeable inhibitors of mammalian PDH E1. We envision that our SAR findings and inhibitors will aid work on using chemical inhibition to understand the oncogenic role of PDHc.

Shaping infant development from the inside out: Bioactive factors in human milk

Human breast milk is the optimal nutrition for all infants and is comprised of many bioactive and immunomodulatory components. The components in human milk, such as probiotics, human milk oligosaccharides (HMOs), extracellular vesicles, peptides, immunoglobulins, growth factors, cytokines, and vitamins, play a critical role in guiding neonatal development beyond somatic growth. In this review, we will describe the bioactive factors in human milk and discuss how these factors shape neonatal immunity, the intestinal microbiome, intestinal development, and more from the inside out.

Thiamine deficiency in pregnancy and lactation: implications and present perspectives

During pregnancy, many physiologic changes occur in order to accommodate fetal growth. These changes require an increase in many of the nutritional needs to prevent long-term consequences for both mother and the offspring. One of the main vitamins that are needed throughout the pregnancy is thiamine (vitamin B1) which is a water-soluble vitamin that plays an important role in many metabolic and physiologic processes in the human body. Thiamine deficiency during pregnancy can cause can have many cardiac, neurologic, and psychological effects on the mother. It can also dispose the fetus to gastrointestinal, pulmonological, cardiac, and neurologic conditions. This paper reviews the recently published literature about thiamine and its physiologic roles, thiamine deficiency in pregnancy, its prevalence, its impact on infants and subsequent consequences in them. This review also highlights the knowledge gaps within these topics.

Thiamine deficiency in Gambian women of reproductive age

Thiamine deficiency disorders are associated with a variety of clinical symptoms affecting the nervous and cardiovascular systems. There is growing recognition that thiamine deficiency can occur in populations well beyond the classical region of South Asia, and at-risk populations include those who receive a large proportion of their energy from polished white rice (or other low-thiamine staple foods) and with low dietary diversity. Reports of thiamine deficiency in West Africa over the last century have suggested that this has historically been an issue in this population, but in more recent decades, these reports have been limited to prison populations. To understand if thiamine deficiency might be an unrecognized problem in the communities of this region, erythrocyte samples collected during the wet and dry seasons from 226 women of reproductive age (mean age = 28 years old) were assessed for thiamine status by measuring the erythrocyte transketolase activity coefficient (ETKac). Overall, 35.8% of the sample was at high risk of thiamine deficiency (ETKac ≥ 1.25). Risk of thiamine deficiency was significantly higher in the wet (47.9%) compared with the dry season (22.9%) (P < 0.001). To our knowledge, this is the first report of biochemical thiamine deficiency in a free-living population in West Africa in the 21st century and suggests that further investigation is warranted.

A case series of rare neurological and cardio-pulmonary manifestations of thiamine deficiency in pregnancy and lactation

Thiamine (vitamin B1) is a sulfur-containing, water-soluble vitamin that plays an essential role in energy metabolism and the tricarboxylic acid cycle. There is an increased need for vitamin B1 (1-1.2 mg daily) during pregnancy and lactation. Hyperemesis during pregnancy can cause severe polyneuropathy (Wernicke's encephalopathy) as a result of thiamine deficiency. Thiamine deficiency has also been associated with beriberi. A number of atypical cases with reversible right heart failure and severe pulmonary hypertension have also been reported in non-pregnant individuals, but have never been reported in pregnancy. Here we present five such cases of thiamine deficiency with neurological and cardio-pulmonary manifestations.

Thiamine fortification strategies in low- and middle-income settings: a review

Thiamine (vitamin B1 ) is an essential micronutrient in energy metabolism and cognitive and neurological health. Thiamine deficiency disorders (TDDs) have a range of clinical presentations that result in various morbidities and can be fatal if not promptly recognized and treated, especially in infants. To intervene, thiamine intakes by breastfeeding mothers and others at risk of thiamine deficiency should be increased to ensure adequate thiamine intake. Although thiamine fortification programs have a long history in high-income countries, there are few mandatory fortification programs to address TDDs in low- and middle-income countries (LMICs), particularly in the regions of greatest concern, South and Southeast Asia. This review highlights essential aspects for consideration in the development of a mandatory fortification program in LMICs, including an overview of the data required to model fortification dosing schemes, available thiamine fortificants, and potential fortification vehicles, as well as identifies current knowledge gaps.

Scoping review of nutrition intervention and dietary assessment studies in Khmer populations living in Cambodia

BACKGROUND

This scoping review aims to describe the body of nutrition intervention and dietary assessment research undertaken with Khmer populations in Cambodia, as well as summarise the nutrition knowledge base and highlight priority areas for future research.

METHODS

Five databases and the grey literature were searched, following PRISMA-ScR guidelines. Studies involving dietary assessment or nutrition interventions published after 1992 were identified using specific search terms and extracted to a customised data extraction table for categorisation and analysis. Study participants were Khmer people of any age and gender, living in rural or urban Cambodia.

RESULTS

Of the 100 included studies, 58 were dietary assessment only studies, 24 were nutrition interventions only, and 18 studies involved both assessment of intake and an intervention. Sixty-eight percent of study populations were mothers and young children, of which 52 studies focused on children aged under 5 years. Nineteen interventions involved supplementation and six trialled fortification of rice or fish sauce. Anaemia was the most common nutrition condition studied (n = 17), followed by malnutrition (n = 15) and malnutrition risk factors (n = 11). General nutrition status was explored in 25 studies, and individual micronutrients that were studied included iron (n = 27), zinc (n = 6), vitamin A (n = 4) and thiamine (n = 3).

CONCLUSIONS

Diet-related research in Khmer populations in Cambodia has predominantly focused on dietary assessment or evaluation of interventions aimed at reducing malnutrition and resolving micronutrient deficiencies. Areas identified as emerging needs included non-communicable diseases, the ageing population and non-iron deficiency anaemia.

Paenibacillus infection with frequent viral coinfection contributes to postinfectious hydrocephalus in Ugandan infants

Postinfectious hydrocephalus (PIH), which often follows neonatal sepsis, is the most common cause of pediatric hydrocephalus worldwide, yet the microbial pathogens underlying this disease remain to be elucidated. Characterization of the microbial agents causing PIH would enable a shift from surgical palliation of cerebrospinal fluid (CSF) accumulation to prevention of the disease. Here, we examined blood and CSF samples collected from 100 consecutive infant cases of PIH and control cases comprising infants with non-postinfectious hydrocephalus in Uganda. Genomic sequencing of samples was undertaken to test for bacterial, fungal, and parasitic DNA; DNA and RNA sequencing was used to identify viruses; and bacterial culture recovery was used to identify potential causative organisms. We found that infection with the bacterium Paenibacillus, together with frequent cytomegalovirus (CMV) coinfection, was associated with PIH in our infant cohort. Assembly of the genome of a facultative anaerobic bacterial isolate recovered from cultures of CSF samples from PIH cases identified a strain of Paenibacillus thiaminolyticus This strain, designated Mbale, was lethal when injected into mice in contrast to the benign reference Paenibacillus strain. These findings show that an unbiased pan-microbial approach enabled characterization of Paenibacillus in CSF samples from PIH cases, and point toward a pathway of more optimal treatment and prevention for PIH and other proximate neonatal infections.

Thiamine levels in Indonesian children with congenital heart diseases undergoing surgery using cardiopulmonary bypass machine

BACKGROUND

This study evaluated thiamine levels in Indonesian children with congenital heart diseases before and after cardiopulmonary bypass and their relationship with clinical and surgical outcomes.

METHOD

A prospective, single center cross-sectional study was conducted to evaluate thiamine levels in 25 children undergoing congenital heart diseases surgery with cardiopulmonary bypass procedure. Thiamine levels were quantified using a high-performance liquid chromatography method.

RESULT

Preoperative thiamine deficiency was observed in one subject. Thiamine levels did not differ statistically between nutritional status and clinical outcomes categories. There were no significant changes in thiamine levels before and after cardiopulmonary bypass (median pre versus post (P_25-75): 50 ng/mL (59.00-116.00) and 83.00 ng/mL (70.00-101.00), p = 0.84), although a significant reduction in thiamine levels were observed with longer cardiopulmonary bypass duration (p = 0.017, R = -0.472).

CONCLUSION

Thiamine levels were not significantly impacted by cardiac surgery except in patients undergoing extremely long cardiopulmonary bypass duration. However, clinical outcome was not affected by thiamine levels.

Low-dose thiamine supplementation of lactating Cambodian mothers improves human milk thiamine concentrations: a randomized controlled trial

BACKGROUND

Infantile beriberi-related mortality is still common in South and Southeast Asia. Interventions to increase maternal thiamine intakes, and thus human milk thiamine, are warranted; however, the required dose remains unknown.

OBJECTIVES

We sought to estimate the dose at which additional maternal intake of oral thiamine no longer meaningfully increased milk thiamine concentrations in infants at 24 wk postpartum, and to investigate the impact of 4 thiamine supplementation doses on milk and blood thiamine status biomarkers.

METHODS

In this double-blind, 4-parallel arm randomized controlled dose-response trial, healthy mothers were recruited in Kampong Thom, Cambodia. At 2 wk postpartum, women were randomly assigned to consume 1 capsule, containing 0, 1.2 (estimated average requirement), 2.4, or 10 mg of thiamine daily from 2 through 24 weeks postpartum. Human milk total thiamine concentrations were measured using HPLC. An Emax curve was plotted, which was estimated using a nonlinear least squares model in an intention-to-treat analysis. Linear mixed-effects models were used to test for differences between treatment groups. Maternal and infant blood thiamine biomarkers were also assessed.

RESULTS

In total, each of 335 women was randomly assigned to1 of the following thiamine-dose groups: placebo (n = 83), 1.2 mg (n = 86), 2.4 mg (n = 81), and 10 mg (n = 85). The estimated dose required to reach 90% of the maximum average total thiamine concentration in human milk (191 µg/L) is 2.35 (95% CI: 0.58, 7.01) mg/d. The mean ± SD milk thiamine concentrations were significantly higher in all intervention groups (183 ± 91, 190 ± 105, and 206 ± 89 µg/L for 1.2, 2.4, and 10 mg, respectively) compared with the placebo group (153 ± 85 µg/L; P < 0.0001) and did not significantly differ from each other.

CONCLUSIONS

A supplemental thiamine dose of 2.35 mg/d was required to achieve a milk total thiamine concentration of 191 µg/L. However, 1.2 mg/d for 22 wk was sufficient to increase milk thiamine concentrations to similar levels achieved by higher supplementation doses (2.4 and 10 mg/d), and comparable to those of healthy mothers in regions without beriberi. This trial was registered at clinicaltrials.gov as NCT03616288.

Infantile thiamine deficiency in South and Southeast Asia: An age-old problem needing new solutions

Infantile beriberi, a potentially fatal disorder caused by thiamine deficiency, is often viewed as a disease confined to history in regions of the world with predominant white rice consumption. Recent case reports have, however, highlighted the persistence of thiamine deficiency as a cause of infant mortality in South and Southeast Asia. Low infant thiamine status and incidence of beriberi is attributable to maternal thiamine deficiency and insufficient breast milk thiamine. Poor dietary diversity, food preparation and cooking practices and traditional post‐partum food restrictions likely play a role in these high‐risk regions. Given the contribution of thiamine deficiency to infant mortality and emerging evidence of long‐lasting neurodevelopmental deficits of severe and even subclinical deficiency in early life, public health strategies to prevent thiamine deficiency are urgently needed. However, efforts are hampered by uncertainties surrounding the identification and assessment of thiamine deficiency, due to the broad non‐specific clinical manifestations, commonly referred to as thiamine deficiency disorders (TDD), that overlap with other conditions resulting in frequent misdiagnosis and missed treatment opportunities, and secondly the lack of readily available and agreed upon biomarker analysis and cut‐off thresholds. This review will discuss the key challenges and limitations in the current understanding of TDD and explore how ongoing initiatives plan to fill persistent knowledge gaps, namely in the development of a standardised case definition to help more accurately diagnose and treat TDD in low‐resource settings. Given more attention and ensuring greater recognition of TDD will support the design and implementation of treatment and prevention programmes, and ensure beriberi can truly be considered ‘the forgotten disease of Asia’.

Assessment of salt intake to consider salt as a fortification vehicle for thiamine in Cambodia

Thiamine deficiency is a public health issue in Cambodia. Thiamine fortification of salt has been proposed; however, the salt intake of lactating women, the target population, is currently unknown. We estimated salt intakes among lactating women (<6 months postpartum) using three methods: repeat observed-weighed intake records and 24-h urinary sodium excretions (n = 104), and household salt disappearance (n = 331). Usual salt intake was estimated by adjusting for intraindividual intakes using the National Cancer Institute method, and a thiamine salt fortification scenario was modeled using a modified estimated average requirement (EAR) cut-point method. Unadjusted salt intake from observed intakes was 9.3 (8.3-10.3) g/day, which was not different from estimated salt intake from urinary sodium excretions, 9.0 (8.4-9.7) g/day (P = 0.3). Estimated salt use from household salt disappearance was 11.3 (10.7-11.9) g/person/day. Usual (adjusted) salt intake from all sources was 7.7 (7.4-8.0) g/day. Assuming no stability losses, a modeled fortification dose of 275 mg thiamine/kg salt could increase thiamine intakes from fortified salt to 2.1 (2.0-2.2) mg/day, with even low salt consumers reaching the EAR of 1.2 mg/day from fortified salt alone. These findings, in conjunction with future sensory and stability research, can inform a potential salt fortification program in Cambodia.

Thiamine deficiency disorders: a clinical perspective

Thiamine is an essential water‐soluble vitamin that plays an important role in energy metabolism. Thiamine deficiency presents many challenges to clinicians, in part due to the broad clinical spectrum, referred to as thiamine deficiency disorders (TDDs), affecting the metabolic, neurologic, cardiovascular, respiratory, gastrointestinal, and musculoskeletal systems. Concurrent illnesses and overlapping signs and symptoms with other disorders can further complicate this. As such, TDDs are frequently misdiagnosed and treatment opportunities missed, with fatal consequences or permanent neurologic sequelae. In the absence of specific diagnostic tests, a low threshold of clinical suspicion and early therapeutic thiamine is currently the best approach. Even in severe cases, rapid clinical improvement can occur within hours or days, with neurological involvement possibly requiring higher doses and a longer recovery time. Active research aims to help better identify patients with thiamine‐responsive disorders and future research is needed to determine effective dosing regimens for the various clinical presentations of TDDs. Understanding the clinical diagnosis and global burden of thiamine deficiency will help to implement national surveillance and population‐level prevention programs, with education to sensitize clinicians to TDDs. With concerted effort, the morbidity and mortality related to thiamine deficiency can be reduced.

Social vulnerability: The connection between psychiatric disorders and thiamine deficiency in pregnant women

The evaluation of thiamine and its derivative phosphate esters levels in pregnant women in rural communities can contribute not only for understanding the specific characteristics of this population regarding nutritional aspects, but also for clarifying the relations of psychiatric manifestations and a vitamin deficit. In the present work we assessed sociodemographic variables, psychiatric parameters and thiamine and its derivative in the whole blood of women in a rural, low-income community in Brazil. A case-control study was done. 94 women were divided in groups using the trimesters of pregnancy as a criterion: each trimester, 1st, 2nd and 3rd had 17, 37 and 38 women, respectively. A control group of non-pregnant women (n-39) was also included. Symptoms of anxiety and depression were assessed using the HAMA Scale and Beck Inventory, respectively. The thiamine and its phosphorylated derivatives concentrations were determined in whole blood samples using the HPLC method. The results suggest that physiological mechanisms linked to the metabolic pathways of thiamine may play a role in some neurobiological substrate involved in the regulation of emotional state. Thus, social vulnerability is identified as an important factor to be considered in the evaluation of the mental health of pregnant women living in rural communities.

Thiamine-Responsive Acute Pulmonary Hypertension of Early Infancy (TRAPHEI)-A Case Series and Clinical Review

Persistent pulmonary hypertension of the newborn (PPHN) is a syndrome of high pulmonary vascular resistance (PVR) commonly seen all over the world in the immediate newborn period. Several case reports from India have recently described severe pulmonary hypertension among infants in the postneonatal period. These cases typically present with respiratory distress in 1–6-month-old infants, breastfed by mothers on a polished rice-based diet. Predisposing factors include respiratory tract infection such as acute laryngotracheobronchitis with change in voice, leading to pulmonary hypertension, right atrial and ventricular dilation, pulmonary edema and hepatomegaly. Mortality is high without specific therapy. Respiratory support, pulmonary vasodilator therapy, inotropes, diuretics and thiamine infusion have improved the outcome of these infants. This review outlines four typical patients with thiamine-responsive acute pulmonary hypertension of early infancy (TRAPHEI) due to thiamine deficiency and discusses pathophysiology, clinical features, diagnostic criteria and therapeutic options.

Comparison of Thiamin Diphosphate High-Performance Liquid Chromatography and Erythrocyte Transketolase Assays for Evaluating Thiamin Status in Malaria Patients without Beriberi

Thiamin deficiency, or beriberi, is an increasingly re-recognized cause of morbidity and mortality in the developing world. Thiamin status has traditionally been measured through the erythrocyte activation assay (ETKA) or basal transketolase activity (ETK), which indirectly measure thiamin diphosphate (TDP). Thiamin diphosphate can also be measured directly by high-performance liquid chromatography (HPLC), which may allow a more precise estimation of thiamin status. We compared the direct measurement of TDP by HPLC with basal ETK activity and ETKA in 230 patients with Plasmodium falciparum malaria in rural southern Laos without overt clinical beriberi, as part of a trial of thiamin supplementation. Admission thiamin status measured by basal ETK activity and ETKA (α) were compared with thiamin status assessed by the measurement of TDP by HPLC. 55% of 230 included patients were male, and the median age was 10 (range 0.5–73) years. Using α ≥ 25% as the gold standard of thiamin deficiency, the sensitivity of TDP < 275 ng/gHb as a measure of thiamin deficiency was 68.5% (95% CI: 54.4–80.5%), with specificity of 60.8 (95% CI: 53.2–68.1%). There was a significant inverse correlation between the results of the two tests (Kendall’s tau = −0.212, P < 0.001). Basal ETK activity was also significantly positively correlated with TDP levels (Kendall’s tau = 0.576, P < 0.001). Thiamin diphosphate measurement may have a role in measuring thiamin levels in clinical settings. Further studies evaluating TDP concentration in erythrocytes with basal ETK activity and ETKA (α) in beriberi patients would help establish comparative values of these assays.

Establishing a case definition of thiamine responsive disorders among infants and young children in Lao PDR: protocol for a prospective cohort study

INTRODUCTION

Diagnosis of infantile thiamine deficiency disorders (TDD) is challenging due to the non-specific, highly variable clinical presentation, often leading to misdiagnosis. Our primary objective is to develop a case definition for thiamine responsive disorders (TRD) to determine among hospitalised infants and young children, which clinical features and risk factors identify those who respond positively to thiamine administration.

METHODS AND ANALYSIS

This prospective study will enrol 662 children (aged 21 days to <18 months) seeking treatment for TDD symptoms. Children will be treated with intravenous or intramuscular thiamine (100 mg daily for a minimum of 3 days) alongside other interventions deemed appropriate. Baseline assessments, prior to thiamine administration, include a physical examination, echocardiogram and venous blood draw for the determination of thiamine biomarkers. Follow-up assessments include physical examinations (after 4, 8, 12, 24, 36, 48 and 72 hours), echocardiogram (after 24 and 48 hours) and one cranial ultrasound. During the hospital stay, maternal blood and breast-milk samples and diet, health, anthropometric and socio-demographic information will be collected for mother-child pairs. Using these data, a panel of expert paediatricians will determine TRD status for use as the dependent variable in logistic regression models. Models identifying predictors of TRD will be developed and validated for various scenarios. Clinical prediction model performance will be quantified by empirical area under the receiver operating characteristic curve, using resampling cross validation. A frequency-matched community-based cohort of mother-child pairs (n=265) will serve as comparison group for evaluation of potential risk factors for TRD.

ETHICS AND DISSEMINATION

Ethical approval has been obtained from The National Ethics Committee for Health Research, Ministry of Health, Lao PDR and the Institutional Review Board of the University of California Davis. The results will be disseminated via scientific articles, presentations and workshops with representatives of the Ministry of Health.

TRIAL REGISTRATION NUMBER

NCT03626337.

Development and validation of a dried blood spot test for thiamine deficiency among infants by HPLC-fluorimetry

Thiamine deficiency, if detected early in infancy, can be treated with thiamine supplementation and can prevent seizures, other disabilities and death. The dried blood spot (DBS) sampling technique is an attractive sample collection technique for infants. The present study reports the development and validation of a highly sensitive and precise method for quantification of thiamine diphosphate from DBS. The method utilizes full-spot analysis of a volumetrically deposited 40 μl DBS. The analyte was extracted from the DBS using 50% methanol and then derivatized using potassium ferricyanide to thiochrome. Separation was achieved with the help of an Inertsil ODS C₁₈ column (5.0 μm, 250 × 4.6 mm) using 150 mm phosphate buffer pH 7-acetonitrile (90:10, % v/v) as the mobile phase. The use of a fluorimetric detector gave a good response to the thiochrome derivative offering good sensitivity for the method. The excitation and emission wavelengths were 367 and 435 nm, respectively. The limit of detection and lower limit of quantification were 5 and 10 ng/ml, respectively. Linearity was demonstrated from 10 to 1000 ng/ml, and precision (CV) was <12.08%, at all tested quality control levels. The method accuracy was 89.34-118.89% with recoveries >80%. Bland-Altman analysis of DBS sampling vs. whole blood demonstrated a mean bias of only 1.16 ng/ml, with a majority of the 60 investigated patient samples lying within 7.2% of the corresponding concentration measured in blood, thereby meeting the clinical desirable biological specification criterion and showing that the two methods are comparable.

Thiamine dose response in human milk with supplementation among lactating women in Cambodia: study protocol for a double-blind, four-parallel arm randomised controlled trial

INTRODUCTION

Thiamine (vitamin B1) deficiency remains a concern in Cambodia where women with low thiamine intake produce thiamine-poor milk, putting their breastfed infants at risk of impaired cognitive development and potentially fatal infantile beriberi. Thiamine fortification of salt is a potentially low-cost, passive means of combating thiamine deficiency; however, both the dose of thiamine required to optimise milk thiamine concentrations as well as usual salt intake of lactating women are unknown.

METHODS AND ANALYSIS

In this community-based randomised controlled trial, 320 lactating women from Kampong Thom, Cambodia will be randomised to one of four groups to consume one capsule daily containing 0, 1.2, 2.4 or 10 mg thiamine as thiamine hydrochloride, between 2 and 24 weeks postnatal. The primary objective is to estimate the dose where additional maternal intake of thiamine no longer meaningfully increases infant thiamine diphosphate concentrations 24 weeks postnatally. At 2, 12 and 24 weeks, we will collect sociodemographic, nutrition and health information, a battery of cognitive assessments, maternal (2 and 24 weeks) and infant (24 weeks only) venous blood samples (biomarkers: ThDP and transketolase activity) and human milk samples (also at 4 weeks; biomarker: milk thiamine concentrations). All participants and their families will consume study-provided salt ad libitum throughout the trial, and we will measure salt disappearance each fortnight. Repeat weighed salt intakes and urinary sodium concentrations will be measured among a subset of 100 participants. Parameters of Emax dose-response curves will be estimated using non-linear least squares models with both 'intention to treat' and a secondary 'per-protocol' (capsule compliance ≥80%) analyses.

ETHICS AND DISSEMINATION

Ethical approval was obtained in Cambodia (National Ethics Committee for Health Research 112/250NECHR), Canada (Mount Saint Vincent University Research Ethics Board 2017-141) and the USA (University of Oregon Institutional Review Board 07052018.008). Results will be shared with participants' communities, as well as relevant government and scientific stakeholders via presentations, academic manuscripts and consultations.

TRIAL REGISTRATION NUMBER

NCT03616288.

Thiamin deficiency in low- and middle-income countries: Disorders, prevalences, previous interventions and current recommendations

BACKGROUND

Thiamin deficiency is a major public health concern in several low- and middle-income countries (LMICs)-current attention to the problem is lacking.

AIM

This review discusses prevalence of thiamin insufficiency and thiamin-deficiency disorders (TDDs) in LMICs, outlines programmatic experience with thiamin interventions, and offers recommendations to improve public-health and research attention to thiamin in LMICs.

DISCUSSION

Thiamin insufficiency, i.e. low-blood-thiamin status, is endemic among several Southeast Asian countries: Cambodia (70-100% of infants and 27-100% of reproductive-age women); Laos (13% of hospitalized infants); Thailand (16-25% of children and 30% of elderly adults). Thiamin deficiency accounts for up to 45% of under-5 deaths in Cambodia, 34% of infant deaths in Laos, and 17% of infant deaths in Myanmar. Deficiency also exists in Africa, Asia, and the Americas, but these instances have typically been isolated. Exclusively breastfed infants of thiamin-deficient mothers are at highest risk for TDD and related death. Intervention strategies that have been employed to combat thiamin deficiency include food processing, fortification, supplementation, dietary diversification, and dietary behaviors, all of which have shown varying levels of effectiveness.

CONCLUSIONS

We recommend universal thiamin-fortification of context-specific staple-foods in LMICs as a promising solution, as well as thiamin supplementation, particularly for pregnant and lactating women. Food processing regulations, dietary diversification, and modification of dietary behaviors to increase consumption of thiamin-rich foods may provide benefits in some circumstances, especially in countries without universal fortification programs or in populations dependent on food aid.

Beriberi Outbreak Among Unauthorised Immigrants in a Detention Camp in Malaysia

In February 2012, a district health authority received three inmates with bilateral leg swelling and difficulty in breathing from a detention camp for unauthorized immigrants. A case control study was conducted. Fasting blood samples of case and control groups were collected according to instructions of the laboratory for determining thiamine level, and their 1 week dietary intake was analyzed. 9% (21/226) of inmates had bilateral leg swelling, and 75% (6/8) of them had low thiamine level (< 66 mmol/L). Their diet contained mainly polished rice and other items with low thiamine contents. Bilateral leg swelling was associated with history of no meat consumption during past 3 months (OR 8.4; CI 2.2-32.1). Patients were treated with 100 mg thiamine intravenously and 5 mg orally per day for 6 weeks. All patients responded well. The management was advised to provide vitamin B complex daily, and encouraged to provide thiamine rich foods.

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

Thiamine is an essential micronutrient that plays a key role in energy metabolism. Many populations worldwide may be at risk of clinical or subclinical thiamine deficiencies, due to famine, reliance on staple crops with low thiamine content, or food preparation practices, such as milling grains and washing milled rice. Clinical manifestations of thiamine deficiency are variable; this, along with the lack of a readily accessible and widely agreed upon biomarker of thiamine status, complicates efforts to diagnose thiamine deficiency and assess its global prevalence. Strategies to identify regions at risk of thiamine deficiency through proxy measures, such as analysis of food balance sheet data and month-specific infant mortality rates, may be valuable for understanding the scope of thiamine deficiency. Urgent public health responses are warranted in high-risk regions, considering the contribution of thiamine deficiency to infant mortality and research suggesting that even subclinical thiamine deficiency in childhood may have lifelong neurodevelopmental consequences. Food fortification and maternal and/or infant thiamine supplementation have proven effective in raising thiamine status and reducing the incidence of infantile beriberi in regions where thiamine deficiency is prevalent, but trial data are limited. Efforts to determine culturally and environmentally appropriate food vehicles for thiamine fortification are ongoing.

Re-emergence of thiamine deficiency disease in the Pacific islands (2014-15): A case-control study

Background

From late 2014 multiple atolls in Kiribati reported an unusual and sometimes fatal illness. We conducted an investigation to identify the etiology of the outbreak on the most severely affected atoll, Kuria, and identified thiamine deficiency disease as the cause. Thiamine deficiency disease has not been reported in the Pacific islands for >5 decades. We present the epidemiological, clinical, and laboratory findings of the investigation.

Methodology/Principal findings

We initially conducted detailed interviews and examinations on previously identified cases to characterize the unknown illness and develop a case definition. Active and passive surveillance was then conducted to identify additional cases. A questionnaire to identify potential risk factors and blood samples to assay biochemical indices were collected from cases and asymptomatic controls. Thiamine hydrochloride treatment was implemented and the response to treatment was systematically monitored using a five-point visual analogue scale and by assessing resolution of previously abnormal neurological examination findings. Risk factors and biochemical results were assessed by univariate and multivariate analyses. 69 cases were identified on Kuria (7% attack rate) including 34 confirmed and 35 unconfirmed. Most were adults (median age 28 years [range 0–62]) and 83% were male. Seven adult males and two infants died (13% case fatality rate). Resolution of objective clinical signs (78%) or symptoms (94%) were identified within one week of starting treatment. Risk factors included having a friend with thiamine deficiency disease and drinking kava; drinking yeast alcohol reduced the risk of disease. Higher chromium (p<0·001) but not thiamine deficiency (p = 0·66) or other biochemical indices were associated with disease by univariate analyses. Chromium (p<0·001) and thiamine deficiency (p = 0·02) were associated with disease by multivariate analysis.

Conclusions/Significance

An outbreak of thiamine deficiency disease (beriberi) in Kiribati signals the re-emergence of a classic nutritional disease in the Pacific islands after five decades. Although treatment is safe and effective, the underlying reason for the re-emergence remains unknown. Chromium was highly and positively correlated with disease in this study raising questions about the potential role of factors other than thiamine in the biochemistry and pathophysiology of clinical disease.

Thiamine and selected thiamine antivitamins - biological activity and methods of synthesis

Thiamine plays a very important coenzymatic and non-coenzymatic role in the regulation of basic metabolism. Thiamine diphosphate is a coenzyme of many enzymes, most of which occur in prokaryotes. Pyruvate dehydrogenase and 2-oxoglutarate dehydrogenase complexes as well as transketolase are the examples of thiamine-dependent enzymes present in eukaryotes, including human. Therefore, thiamine is considered as drug or diet supplement which can support the treatment of many pathologies including neurodegenerative and vascular system diseases. On the other hand, thiamine antivitamins, which can interact with thiamine-dependent enzymes impeding their native functions, thiamine transport into the cells or a thiamine diphosphate synthesis, are good propose to drug design. The development of organic chemistry in the last century allowed the synthesis of various thiamine antimetabolites such as amprolium, pyrithiamine, oxythiamine, or 3-deazathiamine. Results of biochemical and theoretical chemistry research show that affinity to thiamine diphosphate-dependent enzymes of these synthetic molecules exceeds the affinity of native coenzyme. Therefore, some of them have already been used in the treatment of coccidiosis (amprolium), other are extensively studied as cytostatics in the treatment of cancer or fungal infections (oxythiamine and pyrithiamine). This review summarizes the current knowledge concerning the synthesis and mechanisms of action of selected thiamine antivitamins and indicates the potential of their practical use.

Effect of blood thiamine concentrations on mortality: Influence of nutritional status

OBJECTIVE

To test the hypothesis that low blood thiamine concentrations in malnourished critically ill children are associated with higher risk of 30-d mortality.

METHODS

Prospective cohort study in 202 consecutively admitted children who had whole blood thiamine concentrations assessed on admission and on days 5 and 10 of intensive care unit (ICU) stay. The primary outcome variable was 30-d mortality. Mean blood thiamine concentrations within the first 10 d of ICU stay, age, sex, malnutrition, C-reactive protein concentration, Pediatric Index of Mortality 2 score, and severe sepsis/septic shock were the main potential exposure variables for outcome.

RESULTS

Thiamine deficiency was detected in 61 patients within the first 10 d of ICU stay, 57 cases being diagnosed on admission and 4 new cases on the 5th d. C-reactive protein concentration during ICU stay was independently associated with decreased blood thiamine concentrations (P = 0.003). There was a significant statistical interaction between mean blood thiamine concentrations and malnutrition on the risk of 30-d mortality (P = 0.002). In an adjusted analysis, mean blood thiamine concentrations were associated with a decrease in the mortality risk in malnourished patients (odds ratio = 0.85; 95% confidence interval [CI]: 0.73-0.98; P = 0.029), whereas no effect was noted for well-nourished patients (odds ratio: 1.03; 95% CI: 0.94-1.13; P = 0.46).

CONCLUSIONS

Blood thiamine concentration probably has a protective effect on the risk of 30-d mortality in malnourished patients but not in those who were well nourished.

The effect of subclinical infantile thiamine deficiency on motor function in preschool children

We investigated the long-term implications of infantile thiamine (vitamin B1) deficiency on motor function in preschoolers who had been fed during the first 2 years of life with a faulty milk substitute. In this retrospective cohort study, 39 children aged 5-6 years who had been exposed to a thiamine-deficient formula during infancy were compared with 30 age-matched healthy children with unremarkable infant nutritional history. The motor function of the participants was evaluated with The Movement Assessment Battery for Children (M-ABC) and the Zuk Assessment. Both evaluation tools revealed statistically significant differences between the exposed and unexposed groups for gross and fine motor development (p < .001, ball skills p = .01) and grapho-motor development (p = .004). The differences were especially noteworthy on M-ABC testing for balance control functioning (p < .001, OR 5.4; 95% CI 3.4-7.4) and fine motor skills (p < .001, OR 3.2; 95% CI 1.8-4.6). In the exposed group, both assessments concurred on the high rate of children exhibiting motor function difficulties in comparison to unexposed group (M-ABC: 56% vs. 10%, Zuk Assessment: 59% vs. 3%, p < .001). Thiamine deficiency in infancy has long-term implications on gross and fine motor function and balance skills in childhood, thiamine having a crucial role in normal motor development. The study emphasizes the importance of proper infant feeding and regulatory control of breast milk substitutes.

Thiamine content of F-75 therapeutic milk for complicated severe acute malnutrition: time for a change?

Since community-based management of severe acute malnutrition has become the standard of care, the clinical profile of severe acutely malnourished patients admitted to hospitals or inpatient therapeutic feeding centers has changed significantly. These patients are usually very ill and often present with several comorbidities, such as shock, sepsis, and pneumonia. Complicated severe acute malnutrition patients are at risk of thiamine insufficiency, and critically ill patients have higher thiamine requirements. The thiamine content of F-75, the therapeutic milk formula used in the early stabilization phase of refeeding in patients with severe acute malnutrition, seems insufficient. Here, we discuss the need and rationale for a substantial increase in the thiamine content of F-75.

High prevalence of thiamine (vitamin B1) deficiency in early childhood among a nationally representative sample of Cambodian women of childbearing age and their children

BACKGROUND

Thiamine deficiency is thought to be an issue in Cambodia and throughout Southeast Asia due to frequent clinical reports of infantile beriberi. However the extent of this public health issue is currently unknown due to a lack of population-representative data. Therefore we assessed the thiamine status (measured as erythrocyte thiamine diphosphate concentrations; eThDP) among a representative sample of Cambodian women of childbearing age (15-49 y) and their young children (6-69 mo).

METHODOLOGY/PRINCIPLE FINDINGS

Samples for this cross-sectional analysis were collected as part of a national micronutrient survey linked to the Cambodian Demographic and Health Survey (CDHS) 2014. One-sixth of households taking part in the CDHS were randomly selected and re-visited for additional blood sampling for eThDP analysis (719 women and 761 children). Thiamine status was assessed using different cut-offs from literature. Women were mean (SD) 30 (6) y, and children (46% girls) were 41 (17) mo. Women had lower mean (95% CI) eThDP of 150 nmol/L (146-153) compared to children, 174 nmol/L (171-179; P < 0.001). Using the most conservative cut-off of eThDP < 120 nmol/L, 27% of mothers and 15% of children were thiamine deficient, however prevalence rates of deficiency were as high as 78% for mothers and 58% for children using a cut-off of < 180 nmol/L. Thiamine deficiency was especially prevalent among infants aged 6-12 mo: 38% were deficient using the most conservative cut-off (< 120 nmol/L).

CONCLUSIONS/SIGNIFICANCE

There is a lack of consensus on thiamine status cut-offs; more research is required to set clinically meaningful cut-offs. Despite this, there is strong evidence of suboptimal thiamine status among Cambodian mothers and their children, with infants <12 mo at the highest risk. Based on eThDP from this nationally-representative sample, immediate action is required to address thiamine deficiency in Cambodia, and likely throughout Southeast Asia.

Comparable Performance Characteristics of Plasma Thiamine and Erythrocyte Thiamine Diphosphate in Response to Thiamine Fortification in Rural Cambodian Women

Background: Traditionally, vitamin B₁ status is assessed by a functional test measuring erythrocyte transketolase (ETK) activity or direct measurement of erythrocyte thiamine diphosphate (eThDP) concentration. However, such analyses are logistically challenging, and do not allow assessment of vitamin B₁ status in plasma/serum samples stored in biobanks. Using a multiplex assay, we evaluated plasma concentrations of thiamine and thiamine monophosphate (TMP), as alternative, convenient measures of vitamin B₁ status. Methods: We investigated the relationships between the established biomarker eThDP and plasma concentrations of thiamine and TMP, and compared the response of these thiamine forms to thiamine fortification using samples from 196 healthy Cambodian women (aged 18–45 years.). eThDP was measured by high performance liquid chromatography with fluorescence detection (HPLC-FLD) and plasma thiamine and TMP by high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS). Results: Plasma thiamine and TMP correlated significantly with eThDP at baseline and study-end (p < 0.05). Among the fortification groups, the strongest response was observed for plasma thiamine (increased by 266%), while increases in plasma TMP (60%) and eThDP (53%) were comparable. Conclusions: Plasma thiamine and TMP correlated positively with eThDP, and all thiamine forms responded significantly to thiamine intervention. Measuring plasma concentrations of thiamine forms is advantageous due to convenient sample handling and capacity to develop low volume, high-throughput, multiplex assays.

No Camphor Toxicity in Cambodian Infants

Thiamine deficiency and beriberi are prevalent in Cambodia, although most infants with nonspecific clinical symptoms of beriberi, including tachypnea, lack echocardiographic evidence diagnostic of the disease. Camphor activates transient receptor potential vanilloid 3 (TRPV3), a nonselective ion channel expressed in the medial preoptic nucleus of the hypothalamus and thought to be important for thermo-sensitivity. Because camphorated ointments are used commonly among Cambodian infants, we hypothesized that topical camphor modulates thermoregulatory behaviors, causing beriberi-simulating tachypnea, separate from any influence of thiamine deficiency. We assessed 9 tachypneic and 10 healthy infants for Tiger Balm use and for presence of camphor in whole blood. However, no camphor was found in blood from any infants, indicating that camphor is unrelated to tachypneic illness in Cambodian infants.

Thiamine deficiency in tachypnoeic Cambodian infants

BACKGROUND

Beriberi is endemic in South-east Asia. Diagnosis is based on clinical findings, but correlation of clinical features with blood thiamine concentrations is uncertain.

OBJECTIVES

To investigate in tachypnoeic Cambodian infants the correlation between whole blood thiamine diphosphate (TDP) concentrations, clinical findings and blood TDP levels after therapy.

METHODS

Infants hospitalised with tachypnoea were enrolled from October 2011 to January 2012. Initial clinical features, diagnostic test results and final diagnoses were recorded. Blood for TDP determination was collected prior to treatment and at discharge. Matched infants from the general outpatient clinic with minor complaints were enrolled as controls. Thiamine was administered at the discretion of the treating paediatrician.

RESULTS

Of the 47 tachypnoeic and 47 control infants, median initial blood TDP concentrations were 83 and 93 nmol/L, respectively (P = 0·69), and were below the estimated limit of normal (<70 nmol/L) in 43% vs 34% (P = 0·40). Median initial TDP levels were 72 and 91 nmol/L in tachypnoeic infants who did or did not receive thiamine, respectively (P = 0·56); at hospital discharge, median TDP concentration had increased by 107 and 3·5 nmol/L in these two subgroups (P<0·001). Classical findings of beriberi such as dysphonia, tachycardia and hepatomegaly did not correlate with low initial TDP concentrations, but infant age, Tiger Balm use, absence of wheezing and low blood CRP levels were associated with low initial TDP levels. Use of infant formula was associated with higher initial TDP levels.

CONCLUSIONS

Thiamine deficiency is common in tachypnoeic Cambodian infants, but routine clinical assessments do not accurately identify those with low blood TDP concentrations. Parenteral thiamine administration markedly increases TDP levels. Empirical thiamine treatment should be considered for tachypnoeic infants in regions with endemic thiamine deficiency.

Thiamine Deficiency in Tropical Pediatrics: New Insights into a Neglected but Vital Metabolic Challenge

In humans, thiamine is a micronutrient prone to depletion that may result in severe clinical abnormalities. This narrative review summarizes current knowledge on thiamine deficiency (TD) and bridges the gap between pathophysiology and clinical presentation by integrating thiamine metabolism at subcellular level with its function to vital organs. The broad clinical spectrum of TD is outlined, with emphasis on conditions encountered in tropical pediatric practice. In particular, TD is associated with type B lactic acidosis and classic forms of beriberi in children, but it is often unrecognized. Other severe acute conditions are associated with hypermetabolism, inducing a functional TD. The crucial role of thiamine in infant cognitive development is also highlighted in this review, along with analysis of the potential impact of TD in refeeding syndrome during severe acute malnutrition (SAM). This review aims to increase clinical awareness of TD in tropical settings where access to diagnostic tests is poor, and advocates for an early therapeutic thiamine challenge in resource-limited settings. Moreover, it provides evidence for thiamine as treatment in critical conditions requiring metabolic resuscitation, and gives rationale to the consideration of increased thiamine supplementation in therapeutic foods for malnourished children.

Infantile encephalitic beriberi: magnetic resonance imaging findings

BACKGROUND

Thiamine deficiency in infants is still encountered in developing countries. It may present with acute neurological manifestations of infantile encephalitic beriberi.

OBJECTIVE

To review brain MRI findings in infantile encephalitic beriberi from a single institution.

MATERIALS AND METHODS

A retrospective review of MRI scans in 22 infants with acute-onset beriberi encephalopathy was carried out.

RESULTS

Hyperintense lesions on T2-weighted images were seen symmetrically in the putamen in all patients, in the caudate nuclei in 16/22 (73%), the thalami in 7/22 (32%) and the globi pallidi in 3/22 (14%) of the infants. Altered signal intensity lesions in the cerebral cortex were seen in 7/22 (32%). The mammillary bodies were seen in one infant and the periaqueductal gray matter in two. There was restricted diffusion in 14/22 (64%), and 6/8 children with no evidence of restriction had been imaged ≥10 days after presentation. MR spectroscopy showed increased lactate peak in 6/8 infants (75%).

CONCLUSION

Recognition of symmetrical T2-W hyperintense lesions in the basal ganglia with restricted diffusion and prominent lactate peak may allow early diagnosis of encephalitic beriberi in at-risk infants.

Poor thiamin and riboflavin status is common among women of childbearing age in rural and urban Cambodia

BACKGROUND

Thiamin deficiency in infancy is the underlying cause of beriberi, which can be fatal without rapid treatment. Reports of thiamin deficiency are common in Cambodia; however, population representative data are unavailable. Because B-complex vitamin deficiencies commonly occur in combination, riboflavin was also investigated.

OBJECTIVE

We determined the biomarker status of thiamin and riboflavin in women of childbearing age in rural and urban Cambodia.

METHODS

We measured thiamin (erythrocyte thiamin diphosphate; TDP) and riboflavin (erythrocyte glutathione reductase activity coefficient; EGRac) status in a representative sample of Cambodian women (aged 20-45 y) in urban Phnom Penh (n = 146) and rural Prey Veng (n = 156), Cambodia, and, for comparison purposes, in a convenience sample of women in urban Vancouver, British Columbia, Canada (n = 49).

RESULTS

Thiamin insufficiency (TDP ≤ 90 nmol/L) was common among both urban (39%) and rural (59%) Cambodian women (P < 0.001), whereas <20% of Vancouver women were thiamin insufficient (P < 0.001). The prevalence of suboptimal and deficient riboflavin status (EGRac ≥ 1.3) was 89%, 92%, and 70% among women in Phnom Penh, Prey Veng, and Vancouver, respectively (P < 0.001).

CONCLUSIONS

Suboptimal status of both thiamin and riboflavin were common in Cambodian women, with substantially higher rates among women living in rural Prey Veng than in urban Phnom Penh. Strategies may be needed to improve the thiamin and riboflavin status of women in Cambodia. The unexpected finding of high riboflavin inadequacy status in Vancouver women warrants further investigation.

Thiamine deficiency and cardiac dysfunction in Cambodian infants

OBJECTIVES

To compare blood thiamine concentrations, echocardiography findings, and plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels in infants with clinically diagnosed beriberi and healthy matched controls, and to evaluate changes after thiamine treatment.

STUDY DESIGN

Sixty-two Cambodian infants (20 cases and 42 controls), aged 2-47 weeks, were enrolled in this prospective study. Echocardiography and phlebotomy were performed at baseline and after thiamine treatment.

RESULTS

Both cases and controls were thiamine-deficient, with median blood thiamine diphosphate (TDP) concentrations of 47.6 and 55.1 nmol/L, respectively (P = .23). All subjects had normal left ventricular ejection fraction. The median NT-proBNP concentration in cases (340 pg/mL [40.1 pmol/L]) was higher than previously reported normal ranges, but not statistically significantly different from that in controls (175 pg/mL [20.7 pmol/L]) (P = .10), and was not correlated with TDP concentration (P = .13). Two cases with the lowest baseline TDP concentrations (24 and 21 nmol/L) had right ventricular enlargement and elevated NT-proBNP levels that improved dramatically by 48 hours after thiamine administration.

CONCLUSION

Only a minority of thiamine-deficient Cambodian infants demonstrate abnormal echocardiography findings. Thiamine deficiency produces echocardiographic evidence of right ventricular dysfunction, but this evidence is not apparent until deficiency is severe. NT-proBNP concentrations are mildly elevated in sick infants with normal echocardiography findings, indicating possible physiological changes not yet associated with echocardiographic abnormalities.

Thiamine pharmacokinetics in Cambodian mothers and their breastfed infants

BACKGROUND

Thiamine deficiency is common in parts of Asia and causes beriberi. Pharmacokinetics of thiamine in deficient populations are unknown.

OBJECTIVE

We characterized thiamine pharmacokinetics in Cambodian mothers and their breastfed infants.

DESIGN

Total plasma thiamine, whole-blood thiamine diphosphate (TDP), and breast milk total thiamine were measured in 16 healthy Cambodian mothers and their infants before and after mothers received oral thiamine hydrochloride (100 mg for 5 d). Assays were also performed in 16 healthy American mothers.

RESULTS

On day 1, Cambodian mothers were thiamine deficient, with median (range) total plasma thiamine and TDP concentrations of 2.4 nmol/L (0-4.4 nmol/L) and 58.0 nmol/L (27-98 nmol/L), respectively. After a single oral dose, the mean ± SD maximal concentration of thiamine and net area under the thiamine concentration-time curve were 73.4 ± 45.6 nmol/L and 465 ± 241 h · nmol ∙ L⁻¹. Day 6 median maternal total plasma thiamine and TDP concentrations were normal [18.6 nmol/L (13.4-25.3 nmol/L) and 76.5 nmol/L (48-107 nmol/L), respectively; P ≤ 0.001 compared with day 1]. Median Cambodian total breast milk thiamine concentration increased from 180 nmol/L (85-359 nmol/L) on day 1 to 403 nmol/L (314-415 nmol/L) on day 2 and 503 nmol/L (360-808 nmol/L) on day 6; the corresponding American breast milk value was 500 nmol/L (114-622 nmol/L). Median Cambodian infant total plasma thiamine and TDP concentrations increased from 3.0 nmol/L (0-7.3 nmol/L) and 38.5 nmol/L (23-57 nmol/L), respectively, on day 1 to 5.6 nmol/L (0-9.7 nmol/L) and 45.5 nmol/L (32-70 nmol/L), respectively, on day 6.

CONCLUSIONS

Thiamine-deficient Cambodian mothers effectively absorb oral thiamine, with sharp increases in breast milk thiamine concentrations, but their breastfed infants remain thiamine deficient after 5 d of maternal supplementation. Longer-term maternal supplementation may be necessary to correct thiamine deficiency in breastfed infants. This trial was registered at clinicaltrials.gov as NCT01864057.