Host Fecal mRNAs Predicted Environmental Enteric Dysfunction among Children with Moderate Acute Malnutrition in Sierra Leone

Examining the role of environmental enteric dysfunction (EED) in child growth requires noninvasive, field-appropriate biomarkers. Alternatives to the traditionally used lactulose:mannitol (L:M) test have been explored, but few studies have compared the L:M test to host fecal mRNA transcripts. The objectives of this study were to examine whether 1) host fecal mRNA transcripts could predict presence and severity of EED, measured using the L:M test, and 2) EED modifies the effect of specialized nutritious foods (SNFs) on recovery from moderate acute malnutrition (MAM). This substudy was nested within a cluster randomized trial comparing four SNFs in the treatment of MAM among children 6 to 59 months in Sierra Leone. EED was assessed at enrollment using the L:M test and 15 host fecal mRNA transcripts on 522 children. Recovery from MAM was defined as achieving mid-upper arm circumference ≥ 12.5 cm within 12 weeks of supplementation. Random forest classification models were used to examine prediction of presence and severity of EED by host fecal mRNA transcripts. Logistic regression was used to test for effect modification by L:M test variables including % lactulose excreted (%L). Eight host fecal mRNA transcripts (AQP9, REG3A, IFI30, DECR1, BIRC3, SELL, PIK3AP1, DEFA6) identified EED (%L ≥ 0.2) and severe EED (%L ≥ 0.45) with high sensitivity and specificity. The L:M test variables did not modify the effect of SNFs on recovery from MAM. In this study, we found host fecal mRNA transcripts that could be biomarkers of EED but did not find EED to modify the effect of SNFs on MAM treatment.

Effectiveness and cost-effectiveness of 4 supplementary foods for treating moderate acute malnutrition: results from a cluster-randomized intervention trial in Sierra Leone

BACKGROUND

Moderate acute malnutrition (MAM) affects 33 million children annually. Investments in formulations of corn-soy blended flours and lipid-based nutrient supplements have effectively improved MAM recovery rates. Information costs and cost-effectiveness differences are still needed.

OBJECTIVES

We assessed recovery and sustained recovery rates of MAM children receiving a supplementary food: ready-to-use supplementary food (RUSF), corn soy whey blend with fortified vegetable oil (CSWB w/oil), or Super Cereal Plus with amylase (SC + A) compared to Corn Soy Blend Plus with fortified vegetable oil (CSB+ w/oil). We also estimated differences in costs and cost effectiveness of each supplement.

METHODS

In Sierra Leone, we randomly assigned 29 health centers to provide a supplement containing 550 kcal/d for ∼12 wk to 2691 children with MAM aged 6-59 mo. We calculated cost per enrollee, cost per child who recovered, and cost per child who sustained recovery each from 2 perspectives: program perspective and caregiver perspective, combined.

RESULTS

Of 2653 MAM children (98.6%) with complete data, 1676 children (63%) recovered. There were no significant differences in the odds of recovery compared to CSB+ w/oil [0.83 (95% CI: 0.64-1.08) for CSWB w/oil, 1.01 (95% CI: 0.78-1.3) for SC + A, 1.05 (95% CI: 0.82-1.34) for RUSF]. The odds of sustaining recovery were significantly lower for RUSF (0.7; 95% CI 0.49-0.99) but not CSWB w/oil or SC + A [1.08 (95% CI: 0.73-1.6) and 0.96 (95% CI: 0.67-1.4), respectively] when compared to CSB+ w/oil. Costs per enrollee [US dollars (USD)/child] ranged from $105/child in RUSF to $112/child in SC + A and costs per recovered child (USD/child) ranged from $163/child in RUSF to $179/child in CSWB w/oil, with overlapping uncertainty ranges. Costs were highest per sustained recovery (USD/child), ranging from $214/child with the CSB+ w/oil to $226/child with the SC + A, with overlapping uncertainty ranges.

CONCLUSIONS

The 4 supplements performed similarly across recovery (but not sustained recovery) and costed measures. Analyses of posttreatment outcomes are necessary to estimate the full cost of MAM treatment. This trial was registered at clinicaltrials.gov as NCT03146897.

Body Composition Changes in Children during Treatment for Moderate Acute Malnutrition: Findings from a 4-Arm Cluster-Randomized Trial in Sierra Leone

BACKGROUND

Measures that better describe "healthy" and sustainable recovery during nutritional treatment of children with moderate acute malnutrition (MAM) are needed.

OBJECTIVES

We compared changes to body composition among children receiving 1 of 4 specialized nutritious food (SNFs) during treatment of MAM and by recovery and relapse outcomes.

METHODS

The study was nested within a prospective, cluster-randomized, community-based, cost-effectiveness trial assessing 4 SNFs to treat children aged 6-59 mo with MAM [midupper arm circumference (MUAC) ≥11.5 cm and <12.5 cm without bipedal edema] in Sierra Leone. Biweekly SNF rations (1 of 3 fortified-blended foods or a lipid-based nutrient supplement) were given until children recovered (MUAC ≥12.5 cm), or up to 7 rations (∼12 wk). Deuterium dilution was used to estimate fat-free mass (FFM) and fat mass (FM) at enrollment and after 4 wk of treatment to ensure similar treatment exposure among the participants. Another MUAC measurement was performed among recovered children 4 wk after program exit to determine whether recovery was sustained. ANOVA, paired t tests, and linear regression models were used to determine significant differences in changes from baseline to 4 wk.

RESULTS

Among 312 analyzed participants, mean baseline weight comprised ∼80% FFM; mean weight gained after 4 wk comprised ∼82% FFM. Changes in FM and FFM among 4 SNFs were similar. Children who recovered gained more weight (241%), FFM (179%), and weight-for-height z score (0.44 compared with 0) compared with those who did not recover; sustainers gained 150% more weight. FM gains were positive among recovered children and sustainers, as well as negative among those who did not recover or sustain recovery, but not significantly different.

CONCLUSIONS

Four SNFs had similar effects on body composition in children after 4 wk of treatment for MAM, showing a healthy pattern of weight gain, the majority being FFM. Differential responses to treatment underscore a need for further research to provide targets for healthy, sustainable recovery. This trial was registered at clinicaltrials.gov as NCT03146897.

Biomarkers of environmental enteric dysfunction are differently associated with recovery and growth among children with moderate acute malnutrition in Sierra Leone

BACKGROUND

Environmental enteric dysfunction (EED) may influence growth during and recovery from moderate acute malnutrition (MAM), however, biomarkers to assess these relations have yet to be identified.

OBJECTIVES

The objectives of this study were to: 1) develop a score for EED based on host fecal mRNA transcripts, 2) compare biomarkers of EED with each other, and 3) examine associations between the EED biomarkers and recovery from MAM and growth outcomes.

METHODS

In a cohort of 520 Sierra Leonean MAM children, biomarkers of EED included the lactulose: mannitol (L: M) test, 15 host fecal mRNA transcripts, and host fecal proteins [α-1-antitrypsin (AAT), myeloperoxidase (MPO), neopterin (NEO)]. Anthropometry data were also collected and z scores were computed for length-for-age (LAZ) and weight-for-length (WLZ). Recovery from MAM was defined as midupper arm circumference ≥12.5 cm. Factor analysis was used to identify EED scores using the mRNA transcripts, and mixed effects regression was conducted to test for associations.

RESULTS

The 15 host fecal mRNA transcripts were clustered into 3 scores: gut inflammation (GI) score, gut structure (GS) score, and gut defense (GD) score. We found agreement between certain inflammation markers (GI score and MPO), and permeability markers (GS score and AAT; AAT and the L: M excretion ratio). Antimicrobial gut defense (GD score) was inversely associated with percent lactulose excreted, a measure of intestinal permeability. LAZ (β: -0.08; 95% CI: -0.14, -0.02) and WLZ (β: -0.03; 95% CI: -0.06, -0.01) were negatively associated with GI score. A high GD score (β: 0.36; 95% CI: 0.08, 0.64) and low AAT (β: -1.35; 95% CI: -2.35, -0.36) were associated with recovery from MAM.

CONCLUSIONS

Scores derived from host fecal mRNA transcript variably correlated with the L: M test and host fecal proteins. Markers of intestinal inflammation, permeability, and defense were associated with growth outcomes and recovery from MAM.

Knowledge gaps in understanding the metabolic and clinical effects of excess folates/folic acid: a summary, and perspectives, from an NIH workshop

Folate, an essential nutrient found naturally in foods in a reduced form, is present in dietary supplements and fortified foods in an oxidized synthetic form (folic acid). There is widespread agreement that maintaining adequate folate status is critical to prevent diseases due to folate inadequacy (e.g., anemia, birth defects, and cancer). However, there are concerns of potential adverse effects of excess folic acid intake and/or elevated folate status, with the original concern focused on exacerbation of clinical effects of vitamin B-12 deficiency and its role in neurocognitive health. More recently, animal and observational studies have suggested potential adverse effects on cancer risk, birth outcomes, and other diseases. Observations indicating adverse effects from excess folic acid intake, elevated folate status, and unmetabolized folic acid (UMFA) remain inconclusive; the data do not provide the evidence needed to affect public health recommendations. Moreover, strong biological and mechanistic premises connecting elevated folic acid intake, UMFA, and/or high folate status to adverse health outcomes are lacking. However, the body of evidence on potential adverse health outcomes indicates the need for comprehensive research to clarify these issues and bridge knowledge gaps. Three key research questions encompass the additional research needed to establish whether high folic acid or total folate intake contributes to disease risk. 1) Does UMFA affect biological pathways leading to adverse health effects? 2) Does elevated folate status resulting from any form of folate intake affect vitamin B-12 function and its roles in sustaining health? 3) Does elevated folate intake, regardless of form, affect biological pathways leading to adverse health effects other than those linked to vitamin B-12 function? This article summarizes the proceedings of an August 2019 NIH expert workshop focused on addressing these research areas.

Small Vessel Cerebrovascular Pathology Identified by Magnetic Resonance Imaging Is Prevalent in Alzheimer's Disease and Mild Cognitive Impairment: A Potential Target for Intervention

BACKGROUND

There is evidence that Alzheimer's disease (AD) has significant cerebrovascular etiopathogenesis. Understanding potentially modifiable risk factors for vascular disease can help design long-term intervention strategies for controlling or preventing cognitive dysfunction attributable to cerebrovascular disease.

OBJECTIVE

To evaluate the presence and severity of markers of cerebrovascular pathology, its relationship to diagnostic categories of dementia, including AD, and association with the metabolic biomarker homocysteine.

METHODS

In a cross-sectional observational study, 340 community-dwelling elders received a clinical evaluation including brain MRI and neuropsychological tests. Dementia and mild cognitive impairment (MCI) were diagnosed by consensus committee. Fasting total plasma homocysteine was measured. Statistical analyses were adjusted for demographics and cerebrovascular risk factors.

RESULTS

Nearly 25% of those diagnosed with AD had small vessel infarcts (SVI). Periventricular white matter hyperintensity (pvWMHI) was prevalent in participants with AD (61%) or MCI (amnesic 61% and non-amnesic 54%, respectively). Participants with SVI and/or pvWMHI also had greater brain atrophy. Homocysteine concentrations were higher in individuals with cerebrovascular findings than in those without. In individuals with cerebrovascular disease, homocysteine was inversely related to executive function (p = 0.022) and directly related to degree of brain atrophy (p = 0.009).

CONCLUSIONS

We demonstrated a significant prevalence of small vessel markers of cerebrovascular pathology in individuals diagnosed with AD, with a significant concurrence between cerebrovascular disease and brain and ventricular atrophy. While current research on AD has focused on amyloid-βpeptide deposition, tau-pathology, and microglial activation and inflammation, greater attention to the cerebrovascular contribution to this neurodegenerative disease presents an additional target for therapeutic prevention and intervention.

Homocysteine and Dementia: An International Consensus Statement

Identification of modifiable risk factors provides a crucial approach to the prevention of dementia. Nutritional or nutrient-dependent risk factors are especially important because dietary modifications or use of dietary supplements may lower the risk factor level. One such risk factor is a raised concentration of the biomarker plasma total homocysteine, which reflects the functional status of three B vitamins (folate, vitamins B12, B6). A group of experts reviewed literature evidence from the last 20 years. We here present a Consensus Statement, based on the Bradford Hill criteria, and conclude that elevated plasma total homocysteine is a modifiable risk factor for development of cognitive decline, dementia, and Alzheimer’s disease in older persons. In a variety of clinical studies, the relative risk of dementia in elderly people for moderately raised homocysteine (within the normal range) ranges from 1.15 to 2.5, and the Population Attributable risk ranges from 4.3 to 31%. Intervention trials in elderly with cognitive impairment show that homocysteine-lowering treatment with B vitamins markedly slows the rate of whole and regional brain atrophy and also slows cognitive decline. The findings are consistent with moderately raised plasma total homocysteine (>11 μmol/L), which is common in the elderly, being one of the causes of age-related cognitive decline and dementia. Thus, the public health significance of raised tHcy in the elderly should not be underestimated, since it is easy, inexpensive, and safe to treat with B vitamins. Further trials are needed to see whether B vitamin treatment will slow, or prevent, conversion to dementia in people at risk of cognitive decline or dementia.

Biomarkers of Nutrition for Development (BOND): Vitamin B-12 Review

This report on vitamin B-12 (B12) is part of the Biomarkers of Nutrition for Development (BOND) Project, which provides state-of-the art information and advice on the selection, use, and interpretation of biomarkers of nutrient exposure, status, and function. As with the other 5 reports in this series, which focused on iodine, folate, zinc, iron, and vitamin A, this B12 report was developed with the assistance of an expert panel (BOND B12 EP) and other experts who provided information during a consultation. The experts reviewed the existing literature in depth in order to consolidate existing relevant information on the biology of B12, including known and possible effects of insufficiency, and available and potential biomarkers of status. Unlike the situation for the other 5 nutrients reviewed during the BOND project, there has been relatively little previous attention paid to B12 status and its biomarkers, so this report is a landmark in terms of the consolidation and interpretation of the available information on B12 nutrition. Historically, most focus has been on diagnosis and treatment of clinical symptoms of B12 deficiency, which result primarily from pernicious anemia or strict vegetarianism. More recently, we have become aware of the high prevalence of B12 insufficiency in populations consuming low amounts of animal-source foods, which can be detected with ≥1 serum biomarker but presents the new challenge of identifying functional consequences that may require public health interventions.

B-Vitamin Therapy for Kidney Transplant Recipients Lowers Homocysteine and Improves Selective Cognitive Outcomes in the Randomized FAVORIT Ancillary Cognitive Trial

BACKGROUND

Objectives: Elevated plasma total homocysteine (tHcy) is associated with increased risk of cardiovascular disease, stroke and dementia. Results of clinical trials using B-vitamins to reduce the cognitive risks attributed to tHcy have been inconsistent. The high prevalence of both hyperhomocysteinemia and cognitive impairment among kidney transplant recipients makes them an important population in which to evaluate the effect of lowering homocysteine on cognitive function. We therefore evaluated whether B-vitamin therapy to lower tHcy would prevent cognitive-decline in a cohort of stable kidney transplant recipients.

DESIGN

The study was a longitudinal ancillary of the FAVORIT trial, a randomized, placebo-controlled multi-site trial of high-dose B vitamins to reduce cardiovascular and cerebrovascular events in clinically stable kidney transplant recipients with elevated tHcy.

PARTICIPANTS

584 participants from 18 sites across North America.

INTERVENTION

The intervention consisted of a daily multivitamin containing high-doses of folate (5.0 mg), vitamin B12 (1.0 mg) and vitamin B6 (50 mg). The placebo consisted of a daily multi-vitamin containing no folate and recommended daily allowances of vitamins B12 and B6 (0 mg folate; 2.0 µg vitamin B12; 1.4 mg vitamin B6).

MEASUREMENTS

Annual neuropsychological assessment for up to 5 years (mean 3.3 years) using a standardized test battery. Efficacy was analyzed on an intention-to-treat basis using end-of-trial data. Subgroup analyses included stratification for baseline plasma B-vitamin and tHcy concentrations.

RESULTS

At baseline, cognitive impairment was common with 61% of participants falling more than one standard deviation below published norms for at least one cognitive test. Fewer than 1% of participants had insufficient plasma folate < 5 ng/ml or vitamin B12 < 148 pmol/L. However, 44.6% had plasma B6 concentrations < 30 nmol/L. At follow-up, processing speed and memory scores were modestly but significantly better in the B-vitamin supplement group than in controls (p≤0.05). There was no interaction between baseline tHcy, B-vitamin status and treatment on the cognitive outcomes.

CONCLUSIONS

High-dose B-vitamin supplementation provided modest cognitive benefit for kidney transplant recipients with elevated baseline tHcy. Since nearly all participants were folate and vitamin B12 sufficient at baseline, the potential cognitive benefits of folate and B12 supplementation in individuals with poor B-vitamin status remains to be determined.

Children with Poor Linear Growth Are at Risk for Repeated Relapse to Wasting after Recovery from Moderate Acute Malnutrition

Background

Nutrition programs frequently approach wasting and stunting as 2 separate conditions with distinct causes and effects. Although several cross-sectional studies have identified an association between the 2 conditions, longitudinal studies are useful to quantify the risk of acute malnutrition based on the trajectory of linear growth.

Objective

We analyzed data from a longitudinal study to explore associations between linear growth and relapse to acute malnutrition in high-risk children during the year after recovery from moderate acute malnutrition (MAM).

Methods

This was a secondary data analysis from a cluster randomized trial involving 1487 Malawian children 6-62 mo old treated for MAM and enrolled upon recovery. Children were followed for 1 y, during which data were collected on anthropometric progress, symptoms of illness, and household food security. Multivariate fixed-effects logistic regression was used to identify associations between linear growth and relapse to acute malnutrition.

Results

Children who have recovered from MAM proved to be a high-risk population, with nearly half experiencing a decrease in height-for-age z score (HAZ) for 12 mo. Children whose HAZ was declining were more likely to relapse to MAM or SAM than were those whose linear growth rate maintained or increased their HAZ (P < 0.001). Mean changes of +0.15, -0.03, -0.17, and -0.53 in HAZ were observed for those who sustained recovery, relapsed to MAM once, relapsed to MAM multiple times, and developed SAM, respectively.

Conclusion

Our results add to the body of evidence suggesting that acute wasting is a harbinger of subsequent stunting. Children who experience poor linear growth after MAM are more likely to experience relapse. Given this bidirectional relation between wasting and stunting, supplementary feeding programs should consider both when designing protocols, aiming to optimize linear growth and achieve acute weight gain, as a means of reducing relapse. This trial was registered at clinicaltrials.gov as NCT02351687.

Homocysteine and Dementia: An International Consensus Statement

Identification of modifiable risk factors provides a crucial approach to the prevention of dementia. Nutritional or nutrient-dependent risk factors are especially important because dietary modifications or use of dietary supplements may lower the risk factor level. One such risk factor is a raised concentration of the biomarker plasma total homocysteine, which reflects the functional status of three B vitamins (folate, vitamins B12, B6). A group of experts reviewed literature evidence from the last 20 years. We here present a Consensus Statement, based on the Bradford Hill criteria, and conclude that elevated plasma total homocysteine is a modifiable risk factor for development of cognitive decline, dementia, and Alzheimer's disease in older persons. In a variety of clinical studies, the relative risk of dementia in elderly people for moderately raised homocysteine (within the normal range) ranges from 1.15 to 2.5, and the Population Attributable risk ranges from 4.3 to 31%. Intervention trials in elderly with cognitive impairment show that homocysteine-lowering treatment with B vitamins markedly slows the rate of whole and regional brain atrophy and also slows cognitive decline. The findings are consistent with moderately raised plasma total homocysteine (>11 μmol/L), which is common in the elderly, being one of the causes of age-related cognitive decline and dementia. Thus, the public health significance of raised tHcy in the elderly should not be underestimated, since it is easy, inexpensive, and safe to treat with B vitamins. Further trials are needed to see whether B vitamin treatment will slow, or prevent, conversion to dementia in people at risk of cognitive decline or dementia.

Choline and its metabolites are differently associated with cardiometabolic risk factors, history of cardiovascular disease, and MRI-documented cerebrovascular disease in older adults

Background: There is a potential role of choline in cardiovascular and cerebrovascular disease through its involvement in lipid and one-carbon metabolism.Objective: We evaluated the associations of plasma choline and choline-related compounds with cardiometabolic risk factors, history of cardiovascular disease, and cerebrovascular pathology.Design: A cross-sectional subset of the Nutrition, Aging, and Memory in Elders cohort who had undergone MRI of the brain (n = 296; mean ± SD age: 73 ± 8.1 y) was assessed. Plasma concentrations of free choline, betaine, and phosphatidylcholine were measured with the use of liquid-chromatography-stable-isotope dilution-multiple-reaction monitoring-mass spectrometry. A volumetric analysis of MRI was used to determine the cerebrovascular pathology (white-matter hyperintensities and small- and large-vessel infarcts). Multiple linear and logistic regression models were used to examine relations of plasma measures with cardiometabolic risk factors, history of cardiovascular disease, and radiologic evidence of cerebrovascular pathology.Results: Higher concentrations of plasma choline were associated with an unfavorable cardiometabolic risk-factor profile [lower high-density lipoprotein (HDL) cholesterol, higher total homocysteine, and higher body mass index (BMI)] and greater odds of large-vessel cerebral vascular disease or history of cardiovascular disease but lower odds of small-vessel cerebral vascular disease. Conversely, higher concentrations of plasma betaine were associated with a favorable cardiometabolic risk-factor profile [lower low-density lipoprotein (LDL) cholesterol and triglycerides] and lower odds of diabetes. Higher concentrations of plasma phosphatidylcholine were associated with characteristics of both a favorable cardiometabolic risk-factor profile (higher HDL cholesterol, lower BMI, lower C-reactive protein, lower waist circumference, and lower odds of hypertension and diabetes) and an unfavorable profile (higher LDL cholesterol and triglycerides).Conclusion: Choline and its metabolites have differential associations with cardiometabolic risk factors and subtypes of vascular disease, thereby suggesting differing roles in the pathogenesis of cardiovascular and cerebral large-vessel disease compared with that of small-vessel disease.

The Role of Dairy in Effectiveness and Cost of Treatment of Children With Moderate Acute Malnutrition: A Narrative Review

BACKGROUND

Dairy is recommended in specially formulated supplementary foods to treat children with moderate acute malnutrition (MAM) but with limited evidence and added cost.

OBJECTIVE

Review studies of ready-to-use foods (RUFs) versus fortified blended foods (FBFs) to determine whether inclusion of dairy modifies the comparative effectiveness and cost.

METHODS

We reviewed literature comparing FBF and RUF in treatment of MAM among children younger than 5 years in developing countries. Outcomes of recovery from MAM, weight, and length gain were compared among treatment categories: FBF with dairy (FBF+), FBF without dairy (FBF-), RUF with dairy (RUF+), and RUF without dairy (RUF-). Supplement cost was compared per 500 kcal.

RESULTS

Eight studies were included. Rations were heterogeneous in energy and type of dairy. Overall, RUF+, RUF-, and FBF+ performed similarly, with higher recovery and weight gain compared with FBF-. RUF+ had higher recovery (in 5 of 6 comparisons), weight gain (4 of 4), and length gain (1 of 4) versus FBF-. The RUF+ had higher recovery (1 of 2) versus FBF+, with no other differences. The RUF- versus FBF+ had no differences (0 of 2). The RUF- had higher recovery (1 of 2), weight gain (2 of 2) versus FBF-. Four studies reported supplement costs, which averaged US$0.15 (FBF-), US$0.18 (FBF+), US$0.18 (RUF-), and US$0.37 (RUF+) per 500 kcal.

CONCLUSIONS

There is a consistent benefit of FBF that include dairy in treatment of children with MAM. Benefits of dairy in RUF require further investigation. Evidence from rigorous quantitative analysis of existing data, cost-effectiveness, and prospective trials will be essential in determining policy on treatment for children with MAM.

Dihydrofolate reductase 19-bp deletion polymorphism modifies the association of folate status with memory in a cross-sectional multi-ethnic study of adults

BACKGROUND

Folate status has been positively associated with cognitive function in many studies; however, some studies have observed associations of poor cognitive outcomes with high folate. In search of an explanation, we hypothesized that the association of folate with cognition would be modified by the interaction of high-folate status with a common 19-bp deletion polymorphism in the dihydrofolate reductase (DHFR) gene. To our knowledge, the cognitive effects of this gene have not been studied previously.

OBJECTIVE

We examined the association between cognitive outcomes with the 19-bp deletion DHFR polymorphism, folate status, and their interaction with high or normal plasma folate.

DESIGN

This was a pooled cross-sectional study of the following 2 Boston-based cohorts of community living adults: the Boston Puerto Rican Health Study and the Nutrition, Aging, and Memory in Elders study. Individuals were genotyped for the DHFR 19-bp deletion genotype, and plasma folate status was determined. Cognitive outcomes included the Mini-Mental State Examination, Center for Epidemiologic Studies Depression Scale, and factor scores for the domains of memory, executive function, and attention from a set of cognitive tests.

RESULTS

The prevalence of the homozygous deletion (del/del) genotype was 23%. In a multivariable analysis, high folate status (>17.8 ng/mL) was associated with better memory scores than was normal-folate status (fourth-fifth quintiles compared with first-third quintiles: β ± SE = -0.22 ± 0.06, P < 0.01). Carriers of the DHFR del/del genotype had worse memory scores (β ± SE = -0.24 ± 0.10, P < 0.05) and worse executive scores (β = -0.19, P < 0.05) than did those with the del/ins and ins/ins genotypes. Finally, we observed an interaction such that carriers of the del/del genotype with high folate had significantly worse memory scores than those of both noncarriers with high-folate and del/del carriers with normal-folate (β-interaction = 0.26 ± 0.13, P < 0.05).

CONCLUSIONS

This study identifies a putative gene-nutrient interaction that, if confirmed, would predict that a sizable minority carrying the del/del genotype might not benefit from high-folate status and could see a worsening of memory. An understanding of how genetic variation affects responses to high-folate exposure will help weigh risks and benefits of folate supplementation for individuals and public health.

Cerebral blood volume and vasodilation are independently diminished by aging and hypertension: a near infrared spectroscopy study

BACKGROUND

Senescent changes in brain microvascular circulation may cause or contribute to age-related cognitive decline. Such changes are promoted partly by aging, but also by chronic hypertension, a leading treatable cause of cognitive decline.

OBJECTIVES

We aimed to non-invasively detect in vivo the senescent changes in brain microvascular circulation associated with age and hypertension, and inquired whether decrements driven by aging would be exacerbated by chronic hypertension.

METHODS

In this longitudinal study, absolute near infrared spectroscopy (NIRS) was used to quantify in vivo cerebral blood volume (CBV) and assess the hemodynamic response to a hypercapnic respiratory challenge in normotensive Wistar-Kyoto (WKY) and spontaneous-hypertensive (SHR) rats. The impact of age and hypertension were evaluated by repeating these measurements on the same animals at 4- and 16-months of age.

RESULTS

CBV decreased markedly with age in both strains, from 4.5 ± 0.2 to 2.6 ± 0.1 ml/100g tissue, on average. Chronic hypertension, however, did not significantly exacerbate this age-related decrease in CBV (-48.1 ± 3.7% in WKYs versus -53.3 ± 5.4% in SHRs). In contrast, vasoreactivity was already impaired in the young hypertensive rats (ΔVMR 0.017 ± 0.014 in young SHRs versus 0.042 ± 0.005 in young WKYs) and further worsened by middle-age (ΔVMR 0.011 ± 0.017 middle-aged SHRs).

CONCLUSION

Whereas a decrease in brain blood volume correlated with age but not hypertension, vasodilatory capacity was diminished due to hypertension but did not appear affected by age alone. The ability of absolute NIRS to distinguish between such senescent changes in brain (micro)vascular circulation in life may allow early detection and intervention to preserve cerebrovascular health with age.

Environmental enteric dysfunction: pathogenesis, diagnosis, and clinical consequences

Stunting is common in young children in developing countries, and is associated with increased morbidity, developmental delays, and mortality. Its complex pathogenesis likely involves poor intrauterine and postnatal nutrition, exposure to microbes, and the metabolic consequences of repeated infections. Acquired enteropathy affecting both gut structure and function likely plays a significant role in this outcome, especially in the first few months of life, and serve as a precursor to later interactions of infection and malnutrition. However, the lack of validated clinical diagnostic criteria has limited the ability to study its role, identify causative factors, and determine cost-effective interventions. This review addresses these issues through a historical approach, and provides recommendations to define and validate a working clinical diagnosis and to guide critical research in this area to effectively proceed. Prevention of early gut functional changes and inflammation may preclude or mitigate the later adverse vicious cycle of malnutrition and infection.

Implications of acquired environmental enteric dysfunction for growth and stunting in infants and children living in low- and middle-income countries

Changes in small bowel function early in infancy in developing countries are increasingly being demonstrated, probably accompanied by altered mucosal architecture in most individuals, including reduced enterocyte mass and evidence of immune activation and inflammation in the mucosa. These alterations appear to be the result of factors of uncertain nature in the environment, and may be a cause of growth faltering and stunting in young children. For these reasons, this constellation of findings is being referred to as environmental enteropathy, or as we propose herein, environmental enteric dysfunction. If the causes were known and effective interventions were available, strategies and policies to intervene at--or possibly before--birth could be developed and promoted in order to prevent subsequent malnutrition and recurrent infection, which are known to interact in a cyclical and synergistic manner in a downward clinical course often ending in death. Resources would be mobilized and applied differently, and the emphasis would change from treatment to prevention. In order to move in this highly desired direction, investments in research will be required to establish the criteria to assess environmental enteric dysfunction, determine its predictive value for growth faltering and stunting, identify the causes, and propose and test potential interventions. The concepts and tools are available. What is required is the decision to move forward along this pathway to better health for infants and children in low-income countries.

Status of vitamins B-12 and B-6 but not of folate, homocysteine, and the methylenetetrahydrofolate reductase C677T polymorphism are associated with impaired cognition and depression in adults

The C677T polymorphism of the methylenetetrahydrofolate reductase (MTHFR) gene differs in frequency in various ethnic groups that have differing prevalence of age-related cognitive impairments. We used a series of neuro-psychological tests to examine the association of the MTHFR C677T polymorphism with cognition and depression and also to assess whether genotype modifies the association of folate and homocysteine with these outcomes. This study analyzed pooled cross-sectional data from 2 ethnically diverse cohorts of community-living adults: the Boston Puerto Rican Health Study (n = 939) and the Nutrition, Aging, and Memory in Elders study (n = 1017). Individuals in both cohorts underwent anthropometric and laboratory measurements and dietary and health assessments using validated questionnaires between the years 2003 and 2007. Cognitive outcomes included measures of global cognition [Mini-Mental Status Exam (MMSE)], depression (Center for Epidemiological Studies Depression Scale), and 3 factor scores for the domains of attention, executive function, and memory that were derived from a detailed set of neuropsychological tests. Low plasma vitamin B-12 concentrations were associated with poorer MMSE scores and higher depression scores, and low vitamin B-6 concentrations were associated with lower MMSE and worse attention and executive function in the multivariate analysis. In contrast, MTHFR genotype, folate, and homocysteine were not associated with cognition or depression in either ethnicity-pooled or stratified analysis. The current study did not find evidence of an association between the MTHFR C677T TT genotype and impaired cognition or depression in a population with adequate folate status and a high prevalence of cognitive impairment and depression.

Absolute measurement of cerebral optical coefficients, hemoglobin concentration and oxygen saturation in old and young adults with near-infrared spectroscopy

We present near-infrared spectroscopy measurement of absolute cerebral hemoglobin concentration and saturation in a large sample of 36 healthy elderly (mean age, 85 ± 6 years) and 19 young adults (mean age, 28 ± 4 years). Non-invasive measurements were obtained on the forehead using a commercially available multi-distance frequency-domain system and analyzed using a diffusion theory model for a semi-infinite, homogeneous medium with semi-infinite boundary conditions. Our study included repeat measurements, taken five months apart, on 16 elderly volunteers that demonstrate intra-subject reproducibility of the absolute measurements with cross-correlation coefficients of 0.9 for absorption coefficient (μa), oxy-hemoglobin concentration ([HbO2]), and total hemoglobin concentration ([HbT]), 0.7 for deoxy-hemoglobin concentration ([Hb]), 0.8 for hemoglobin oxygen saturation (StO2), and 0.7 for reduced scattering coefficient (μ's). We found significant differences between the two age groups. Compared to young subjects, elderly subjects had lower cerebral [HbO2], [Hb], [HbT], and StO2 by 10 ± 4 μM, 4 ± 3 μM, 14 ± 5 μM, and 6%±5%, respectively. Our results demonstrate the reliability and robustness of multi-distance near-infrared spectroscopy measurements based on a homogeneous model in the human forehead on a large sample of human subjects. Absolute, non-invasive optical measurements on the brain, such as those presented here, can significantly advance the development of NIRS technology as a tool for monitoring resting/basal cerebral perfusion, hemodynamics, oxygenation, and metabolism.

Cognitive dysfunction and depression in adult kidney transplant recipients: baseline findings from the FAVORIT Ancillary Cognitive Trial (FACT)

OBJECTIVE

Hyperhomocysteinemia and B-vitamin deficiency may be treatable risk factors for cognitive impairment and decline. Hyperhomocysteinemia, cognitive impairment, and depression are all common in individuals with kidney disease, including kidney transplant recipients. Accordingly, we assessed the prevalence of cognitive impairment and depressive symptoms in transplant recipients and their association with kidney function, plasma total homocysteine, and B-vitamin concentrations.

SETTING

Cross-sectional analysis of baseline data from the Folic Acid for Vascular Outcome Reduction In Transplantation (FAVORIT) Ancillary Cognitive Trial (FACT), which included 183 participants in FAVORIT who underwent detailed neuropsychological assessment before the study intervention.

RESULTS

The mean age was 54.0 ± 9.5 years (range: 7 to 386 months). Men comprised 55.2% of the cohort, and the mean time between the current transplant and cognitive testing was 7.0 ± 5.8 years. Twenty-four percent of participants reported neurological or psychiatric complaints, and 30% exhibited symptoms of mild to severe depression. Testing revealed evidence of significant and selective deficits in this population: 33% performed more than 1 standard deviation (SD) below normed means on a memory test, 58% fell lower than 1 SD below the norms on a test of attention and mental processing speed, and 33% to 42% fell lower than 1 SD below the norms on several tests of executive function. Lower estimated glomerular filtration rate and lower folate were associated with poorer performance on tests of memory and executive function.

CONCLUSIONS

These observations confirm previous reports of mood and cognitive impairments in adult kidney transplant recipients. Further research is needed to determine the benefit of B-vitamin supplementation and other interventions in this patient population.

Sarcopenia: origins and clinical relevance

To a considerable extent, the advent of the term sarcopenia has contributed to the focus on this important condition and its effects on the quality of life and care of older persons. It is hoped that the advances in our understanding of the etiology and treatment of sarcopenia will further contribute to placing this diagnosis and treatment at a higher priority in the management of older persons and prevention of disability.

Water, hydration, and health

This review examines the current knowledge of water intake as it pertains to human health, including overall patterns of intake and some factors linked with intake, the complex mechanisms behind water homeostasis, and the effects of variation in water intake on health and energy intake, weight, and human performance and functioning. Water represents a critical nutrient, the absence of which will be lethal within days. Water's importance for the prevention of nutrition-related noncommunicable diseases has received more attention recently because of the shift toward consumption of large proportions of fluids as caloric beverages. Despite this focus, there are major gaps in knowledge related to the measurement of total fluid intake and hydration status at the population level; there are also few longer-term systematic interventions and no published randomized, controlled longer-term trials. This review provides suggestions for ways to examine water requirements and encourages more dialogue on this important topic.

Community-level micronutrient fortification of school lunch meals improved vitamin A, folate, and iron status of schoolchildren in Himalayan villages of India

Anemia and micronutrient deficiencies are common among Indian schoolchildren. We assessed the effectiveness of micronutrient fortification of meals cooked and fortified at school on anemia and micronutrient status of schoolchildren in Himalayan villages of India. In this placebo-controlled, cluster-randomized study, 499 schoolchildren (6-10 y) received either multiple micronutrients (treatment group) or placebo (control group) as part of school meals (6 d/wk) for 8 mo. Both groups were dewormed at the beginning of the study. The micronutrient premix provided 10 mg iron, 375 microg vitamin A, 4.2 mg zinc, 225 microg folic acid, and 1.35 microg vitamin B-12 for each child per day (approximately 75% recommended dietary allowance). Blood samples drawn before and after the intervention were analyzed for hemoglobin, ferritin, retinol, zinc, folate, and vitamin B-12. Baseline prevalence of anemia (37%), iron deficiency anemia (10%), low serum ferritin (24%), retinol (56%), zinc (74%), folate (68%), and vitamin B-12 (17%) did not differ between groups. Postintervention, fewer in the treatment group had lower serum retinol [odds ratio (OR) (95% CI): 0.57 (0.33-0.97)] and folate [OR (95% CI): 0.47 (0.26-0.84)] than the control group. The serum vitamin B-12 concentration decreased in both groups, but the magnitude of change was less in the treatment than in the control group (P < 0.05). Total body iron (TBI) increased in both groups; however, the change was greater in the treatment than in the control group (P < 0.05). Micronutrient fortification of school meals by trained school personnel was effective in improving vitamin A, folate, and TBI status while also reducing the magnitude of a decrease in vitamin B-12 status.

MAT1A variants are associated with hypertension, stroke, and markers of DNA damage and are modulated by plasma vitamin B-6 and folate

BACKGROUND

The S-adenosylmethionine synthetase type 1 (MAT1A) gene encodes a key enzyme in one-carbon nutrient metabolism.

OBJECTIVE

This study aimed to determine the association of MAT1A variants with homocysteine, DNA damage, and cardiovascular disease (CVD).

DESIGN

Eight variants of MAT1A were examined for associations with hypertension, stroke, CVD, homocysteine, and DNA damage in 1006 participants of the Boston Puerto Rican Health Study. Two variants were replicated in 1147 participants of the Nutrition, Aging, and Memory in Elders Study.

RESULTS

Two variants and haplotypes were strongly associated with hypertension and stroke, independent of methylenetetrahydrofolate reductase (MTHFR) variants. Homozygotes of the MAT1A d18777A (rs3851059) allele had a significantly greater likelihood of stroke (odds ratio: 4.30; 95% CI: 1.34, 12.19; P = 0.006), whereas 3U1510A (rs7087728) homozygotes had a lower likelihood of hypertension (odds ratio: 0.67; 95% CI: 0.48, 0.95; P = 0.022) and stroke (odds ratio: 0.35; 95% CI: 0.15, 0.82; P = 0.015). A similar trend of association was observed in a second elderly population. Furthermore, strong interactions between MAT1A genotypes and vitamin B-6 status were found. Carriers of the nonrisk allele 3U1510A had a lower 8-hydroxydeoxyguanosine concentration--a biomarker of oxidative DNA damage--when plasma vitamin B-6 was high, whereas homozygotes for the risk-allele 3U1510G had higher 8-hydroxydeoxyguanosine concentrations, regardless of vitamin B-6 status.

CONCLUSIONS

MAT1A variants were strongly associated with hypertension and stroke. Improving folate and vitamin B-6 status might decrease the CVD risk of only a subset of the population, depending on genotype. These findings suggest that impairments in methylation activity, independent of homocysteine, have an effect on CVD risk.

25-Hydroxyvitamin D, dementia, and cerebrovascular pathology in elders receiving home services

BACKGROUND

Vitamin D deficiency has potential adverse effects on neurocognitive health and subcortical function. However, no studies have examined the association between vitamin D status, dementia, and cranial MRI indicators of cerebrovascular disease (CVD).

METHODS

Cross-sectional investigation of 25-hydroxyvitamin D [25(OH)D], dementia, and MRI measures of CVD in elders receiving home care (aged 65-99 years) from 2003 to 2007.

RESULTS

Among 318 participants, the mean age was 73.5 +/- 8.1 years, 231 (72.6%) were women, and 109 (34.3%) were black. 25(OH)D concentrations were deficient (<10 ng/mL) in 14.5% and insufficient (10-20 ng/mL) in 44.3% of participants. There were 76 participants (23.9%) with dementia, 41 of which were classified as probable AD. Mean 25(OH)D concentrations were lower in subjects with dementia (16.8 vs 20.0 ng/mL, p < 0.01). There was a higher prevalence of dementia among participants with 25(OH)D insufficiency (< or =20 ng/mL) (30.5% vs 14.5%, p < 0.01). 25(OH)D deficiency was associated with increased white matter hyperintensity volume (4.9 vs 2.9 mL, p < 0.01), grade (3.0 vs 2.2, p = 0.04), and prevalence of large vessel infarcts (10.1% vs 6.9%, p < 0.01). After adjustment for age, race, sex, body mass index, and education, 25(OH)D insufficiency (< or =20 ng/mL) was associated with more than twice the odds of all-cause dementia (odds ratio [OR] = 2.3, 95% confidence interval [CI] 1.2-4.2), Alzheimer disease (OR = 2.5, 95% CI 1.1-6.1), and stroke (with and without dementia symptoms) (OR = 2.0, 95% CI 1.0-4.0).

CONCLUSIONS

Vitamin D insufficiency and deficiency was associated with all-cause dementia, Alzheimer disease, stroke (with and without dementia symptoms), and MRI indicators of cerebrovascular disease. These findings suggest a potential vasculoprotective role of vitamin D.

Examination of selected national policies towards mandatory folic acid fortification

The purpose of this paper is to present an examination of the contrasting policies towards mandatory folic acid fortification in six countries from different regions of the world. Three questions are addressed: 1) What is the policy of the country? 2) Why was the policy adopted? 3) What lessons have been learned? Policy contrasts among countries were assessed as reflecting different interpretations of the potential risks and benefits associated with folic acid fortification. Although commonalities were identified, it was considered unlikely that there could be a standard policy response for all countries. Instead, a country-by-country policy response based on national circumstances is indicated.

Vitamin D is associated with cognitive function in elders receiving home health services

BACKGROUND

The objective of this study was to examine the association between 25-hydroxyvitamin D, 25(OH)D, and cognitive function.

METHODS

A cross-sectional investigation of 25(OH)D and cognition was completed in 377 black and 703 non-black (mainly Caucasian) elders (65-99 years) participating in the nutrition and memory in elders study. Participants underwent a comprehensive neuropsychological battery, and 25(OH)D concentrations were obtained.

RESULTS

More than 65% of elders had suboptimal 25(OH)D concentrations (< or =20 ng/mL or < or =50 nmol/L). Approximately 18% were deficient in 25(OH)D (<10 ng/mL or <25 nmol/L). After adjusting for age, sex, race, body mass index, education, center, kidney function, seasonality, physical activity, and alcohol use, 25(OH)D was associated with better performance on trails A (beta = -0.49, p < .03), trails B (beta = -0.73, p < .02), digit symbol (beta = 0.19, p < .001), matrix reasoning (beta = 0.04, p < .02), and block design (beta = 0.07, p < .04) tests. Associations remained after adjustment for homocysteine, apoE4 allele, plasma B vitamins, and multivitamin use (y/n). 25(OH)D concentrations >20 ng/mL were associated with better performance on tests of executive function, including trails A (80.5 vs 95, p < .05), trails B (205s vs 226s, p < .05), matrix reasoning (7.8 vs 7.0, p = .03), and digit symbol (31.5 vs 37, p < .01). There were no associations between 25(OH)D and memory tests. Factor analysis yielded factors for memory, executive function, and attention/processing speed. After adjustment, 25(OH)D was associated with the executive function (beta = 0.01, p < 0.01) and attention/processing speed factors (beta = 0.01, p = .03), but not the memory factor (beta = -0.001, p = 0.65).

CONCLUSIONS

25(OH)D was positively associated with cognitive performance, particularly with measures of executive function in this elderly population.