A comparative study on indicators of vitamin A status and risk factors for sensitivity and specificity of the methods to detect vitamin A deficiency.

BACKGROUND: Serum retinol (SR) and retinol-binding protein (RBP) are commonly used indicators, but they are affected by infections and inflammation. This study aimed to assess the sensitivity and specificity of VA indicators to detect vitamin A deficiency (VAD) in 36-59-month-old children living in a rural area in Burkina Faso. METHODS: In a community-based study, two cross-sectional surveys were carried out from November 2016 to September 2017 in the health district of Dandé in Burkina Faso. The surveys included 115 children 36-59 months old. Indicators of VA and inflammation assessed in all children included SR, RBP and total liver VA reserves (TLR) estimated by retinol isotope dilution, and inflammation markers (C-reactive protein (CRP) and alpha 1-acid glycoprotein (AGP)). We calculated the sensitivity, specificity, positive and negative predictive values. In addition, the effects of inflammation, helminth infection, and season on sensitivity and specificity were assessed. RESULTS: The prevalence of VAD assessed by SR (< 0.7 µmol/L), RBP (< 0.7 µmol/L), and TLR (< 0.1 µmol/g liver) were, respectively, 30.9%, 33.3%, and 0%. Compared to TLR, the specificity, positive predictive value, and negative predictive value of SR were 71.1%, 0%, and 100%, and of RBP, were 68.9%, 0%, and 100%, respectively. The sensitivity was indeterminable for SR and RBP. The specificity of SR and RBP was lower during the dry season. Elevated CRP (> 5.0 mg/L) and AGP (> 1.0 g/L) were detected in 1.9% and 28.6% of children, respectively. The adjustment of VA indicators for inflammation improved SR's specificity to 75.9% and decreased RBP's specificity to 67.8%. CONCLUSION: No cases of VAD were identified by TLR. However, (inflammation-adjusted) SR and RBP had varying accuracy in the estimation of VAD. TRIAL REGISTRATION: The study was registered, retrospectively, on 22 March 2018 as a clinical trial with the Pan African Clinical Trials Registry under the number Cochrane South Africa; PACTR201803002999356.

Dietary intake of preformed vitamin A and provitamin A carotenoids are not associated with serum retinol and carotenoid concentrations among children 36-59 months of age in rural Burkina Faso: a cross-sectional study.

PURPOSE: This study aimed to assess the association between dietary intake of preformed vitamin A (VA) and pro-VA carotenoids and serum retinol and carotenoid concentrations among 36-59-month-old children in a rural area in Burkina Faso. METHODS: Two community-based cross-sectional studies were conducted in a rural area of Burkina Faso and included 115 children aged 36-59 months. Dietary intake of preformed VA and pro-VA was assessed directly by 24-h dietary recall. Serum retinol and carotenoid (α- and ß-carotene, and ß-cryptoxanthin) concentrations were measured. The associations between serum retinol and carotenoid concentrations and their respective dietary intake were assessed by multiple linear regression. RESULTS: Geometric mean [95% CI] adjusted serum retinol concentration in children was 0.86 [0.81; 0.92] µmol/L. The prevalence of low adjusted serum retinol concentration (< 0.7 µmol/L) was 26.8%. Geometric mean [95% CI] serum carotenoid concentrations were: α-carotene (0.03 [0.02; 0.03] µmol/L), ß-carotene (0.14 [0.12; 0.16] µmol/L), and ß-cryptoxanthin (0.17 [0.15; 0.21] µmol/L). Dietary intakes of α- and ß-carotene and adjusted serum retinol and α-carotene concentrations were significantly higher during the rainy season. In multiple linear regressions, no associations were found between dietary intakes of preformed VA and pro-VA carotenoids and serum retinol and carotenoid concentrations in children aged 36-59 months in Burkina Faso. There was no effect of season on the associations between preformed VA and pro-VA carotenoids intake and serum retinol and carotenoid concentrations. CONCLUSIONS: This study shows that dietary intakes of preformed VA and pro-VA carotenoids based on 24-h dietary recall method cannot be used as proxy of serum retinol and carotenoid concentrations in this population. TRIAL REGISTRATION: The study was registered retrospectively (22 March 2018) as a clinical trial with the Pan African Clinical Trials Registry (Cochrane South Africa; PACTR201803002999356).

Association between Biomarkers of Inflammation and Total Liver Vitamin A Reserves Estimated by 13C-Retinol Isotope Dilution among Preschool Children in 5 African Countries.

BACKGROUND: Vitamin A (VA) assessment is important for targeting public health programs. Retinol isotope dilution (RID) is a sensitive method to estimate total body VA stores (TBSs) and total liver reserves (TLRs), but the impact of subclinical inflammation on RID is unclear. OBJECTIVE: We determined the association between TBSs and TLRs, estimated by RID, and inflammation among preschool children without clinical infection in Burkina Faso, Cameroon, Ethiopia, South Africa, and Tanzania. METHODS: Five studies (n = 532; 47.9 ± 8.3 mo; 49.0% male) included 13C-RID and measurement of inflammation markers, CRP, and α1-acid glycoprotein (AGP). Spearman correlations were used to evaluate TBSs and TLRs with inflammation biomarkers. Wilcoxon and Kruskal-Wallis tests were used to compare TBSs and TLRs by inflammation categories [normal vs. elevated CRP (>5 mg/L) or AGP (>1 g/L)] and inflammation stage [reference, incubation (elevated CRP), early convalescence (elevated CRP and AGP), and late convalescence (elevated AGP)]. RESULTS: Complete data were available for 439 children. Median (Q1, Q3) TLRs ranged from 0.12 (0.07, 0.18) µmol/g in Ethiopia to 1.10 (0.88, 1.38) µmol/g in South Africa. Elevated CRP ranged from 4% in Burkina Faso to 42% in Cameroon, and elevated AGP from 20% in Tanzania to 58% in Cameroon. Pooled analysis (excluding Cameroon) showed a negative correlation between TBSs and AGP (ρ = -0.131, P = 0.01). Children with elevated AGP had higher probability of having lower TBSs (probability = 0.61, P = 0.002). TBSs differed among infection stages (P = 0.020). Correlations between TLRs and CRP or AGP were not significant. CONCLUSIONS: No indication of systematic bias in RID-estimated TLRs was found due to subclinical inflammation among preschool children. The inverse relationship between TBSs and AGP may reflect decreased stores after infection or an effect of inflammation on isotope partitioning. Further research should investigate potential confounding variables to improve TBS-estimate validity.

Comparison of Total Body Vitamin A Stores Using Individual versus Population 13C-Natural Abundance of Serum Retinol in Preschool Children and Women Residing in 6 Diverse African Countries.

BACKGROUND: Stable isotope techniques using 13C to assess vitamin A (VA) dietary sources, absorption, and total body VA stores (TBSs) require determination of baseline 13C abundance. 13C-natural abundance is approximately 1.1% total carbon, but varies with foods consumed, supplements taken, and food fortification with synthetic retinyl palmitate. OBJECTIVES: We determined 13C variation from purified serum retinol and the resulting impact on TBSs using pooled data from preschool children in Burkina Faso, Cameroon, Ethiopia, South Africa, Tanzania, and Zambia and Zambian women. METHODS: Seven studies included children (n = 639; 56 ± 25 mo; 48% female) and one in women (n = 138; 29 ± 8.5 y). Serum retinol 13C-natural abundance was determined using GC-C-IRMS. TBSs were available in 7 studies that employed retinol isotope dilution (RID). Serum CRP and α1-acid-glycoprotein (AGP) were available from 6 studies in children. Multivariate mixed models assessed the impact of covariates on retinol 13C. Spearman correlations and Bland-Altman analysis compared serum and milk retinol 13C and evaluated the impact of using study- or global-retinol 13C estimates on calculated TBSs. RESULTS: 13C-natural abundance (%, median [Q1, Q3]) differed among countries (low: Zambia, 1.0744 [1.0736, 1.0753]; high: South Africa, 1.0773 [1.0769, 1.0779]) and was associated with TBSs, CRP, and AGP in children and with TBSs in women. 13C-enrichment from serum and milk retinol were correlated (r = 0.52; P = 0.0001). RID in children and women using study and global estimates had low mean bias (range, -3.7% to 2.2%), but larger 95% limits of agreement (range, -23% to 37%). CONCLUSIONS: 13C-natural abundance is different among human cohorts in Africa. Collecting this information in subgroups is recommended for surveys using RID. When TBSs are needed on individuals in clinical applications, baseline 13C measures are important and should be measured in all enrolled subjects.

Monthly measurement of child lengths between 6 and 27 months of age in Burkina Faso reveals both chronic and episodic growth faltering.

BACKGROUND: Linear growth faltering is determined primarily by attained heights in infancy, but available data consist mainly of cross-sectional heights at each age. OBJECTIVES: This study used longitudinal data to test whether faltering occurs episodically in a few months of very low growth, which could potentially be prevented by timely intervention, or is a chronic condition with slower growth in every month of infancy and early childhood. METHODS: Using anthropometric data collected monthly between August 2014 and December 2016, we investigated individual growth curves of 5039 children ages 6-27 mo in Burkina Faso (108,580 observations). We evaluated growth-curve smoothness by level of attained length at ∼27 mo by analyzing variation in changes in monthly growth rates and using 2-stage regressions: 1) regressing each child's length on their age and extracting R2 to represent curve smoothness, initial length, and average velocity by age; and 2) regressing extracted parameters on individual-level attained length. RESULTS: Short children started smaller and remained on their initial trajectories, continuously growing slower than taller children. Growth between 9 and 11 mo was the most influential on attained length; for each 1-cm/mo increase in growth velocity during this period, attained length increased by 6.71 cm (95% CI: 6.59, 6.83 cm). Furthermore, a 0.01 increase in R2 from individual regression of length on age was associated with a 3.10-cm higher attained length (95% CI: 2.80, 3.41 cm), and having 2 consecutive months of slow growth (<15th centile relative to the sample) was associated with 1.7-cm lower attained length (95% CI: -1.80, -1.59 cm), with larger effects in younger children, suggesting that smoother growth patterns were also associated with higher attained length. CONCLUSIONS: Children who experience extreme growth faltering are likely less resilient to systematic growth-limiting conditions as well as episodic insults to their growth.This trial was registered at clinicaltrials.gov as NCT02071563.

Cost-Effectiveness of 4 Specialized Nutritious Foods in the Prevention of Stunting and Wasting in Children Aged 6-23 Months in Burkina Faso: A Geographically Randomized Trial.

BACKGROUND: There is a variety of specialized nutritious foods available for use in programs targeting undernutrition, but evidence supporting the choice of product is limited. OBJECTIVES: We compared the cost-effectiveness of 4 specialized nutritious foods to prevent stunting and wasting in children aged 6-23 mo in Burkina Faso. METHODS: Four geographic regions were randomly assigned to 1 of 4 intervention arms: Corn-Soy Blend Plus (CSB+) programmed with separate fortified vegetable oil (the reference food), Corn-Soy-Whey Blend (CSWB; a new formulation) with oil, SuperCereal Plus (SC+), and ready-to-use supplementary food (RUSF). We compared the effects of each intervention arm on growth (length-for-age z score (LAZ), weight-for-length z score (WLZ), end-line stunting (LAZ < -2), and total monthly measurements of wasting (WLZ < -2). Rations were ∼500 kcal/d, distributed monthly. Children were enrolled in the blanket supplementary feeding program at age ∼6 mo and measured monthly for ∼18 mo. Average costs per child reached were linked with effectiveness to compare the cost-effectiveness of each arm with CSB+ with oil. RESULTS: In our sample of 6112 children (CSB+, n = 1519; CSWB, n = 1503; SC+, n = 1564; RUSF, n = 1526), none of the foods prevented declines in growth. Children in the SC+ and RUSF arms were not significantly different than those in the CSB+ with oil arm. Children in the CSWB with oil arm experienced higher end-line (measurement at age 22.9-23.9 mo) stunting (OR: 2.07; 95% CI: 1.46, 2.94) and more months of wasting (incidence rate ratio: 1.29; 95% CI: 1.09, 1.51). CSB+ with oil was the least-expensive ration in all costing scenarios ($113-131 2018 US dollars/enrolled child) and similar in effectiveness to SC+ and RUSF, and thus the most cost-effective product for the defined purposes. CONCLUSIONS: CSB+ with oil was the most cost-effective ration in the prevention of wasting and stunting in this trial. This trial was registered at clinicaltrials.gov as NCT02071563.

Factors that May Influence the Effectiveness of 4 Specialized Nutritious Foods in the Prevention of Stunting and Wasting in Children Aged 6-23 Months in Burkina Faso.

BACKGROUND: A trial in Burkina Faso compared the cost-effectiveness of 4 specialized nutritious foods (SNFs) used to prevent stunting and wasting in children aged 6-23 mo. OBJECTIVES: This article explores differences in SNF use that may have influenced effectiveness, specifically in relation to consumption by the recipient child and by any other person (i.e., sharing), other diversion from the recipient child, preparation, storage, and hygiene. METHODS: Subsamples from a geographically clustered, longitudinal trial with random assignment to Corn Soy Blend Plus with oil (CSB+ w/oil), Corn Soy Whey Blend with oil (CSWB w/oil), Super Cereal Plus (SC+), or ready-to-use supplementary food (RUSF) were selected for in-depth interviews, in-home observations, and focus group discussions. RESULTS: Sharing was common in all arms, with the highest reported in SC+ (73%) and highest observed in CSWB w/oil (36%). Some reported giving the ration away (highest in SC+ at 17%) or using it for other purposes (highest in CSWB w/oil at 17%). The recipient child was observed consuming the ration in 49% of households on average (38-60% by arm in CSB+ w/oil and RUSF, respectively). Qualitative reports of bitterness and spoilage emerged in the CSWB w/oil arm. Most observed households (excluding RUSF) did not prepare porridge daily as instructed (35-46% by arm). Household water samples showed either high-risk or unsafe contamination with Escherichia coli (72-78% by arm). Low percentages were observed handwashing (both child and server) before consuming the porridge. CONCLUSIONS: The SNFs were not prepared or served as intended and diversion from the recipient was common. Storage conditions may have resulted in spoilage of the ration containing whey before reaching recipients. This article provides context about factors that may have influenced the effectiveness of these SNFs. Programming and household use of SNFs are as important as their nutrient composition. This trial was registered at clinicaltrials.gov as NCT02071563.

Serum Carotenoids Reveal Poor Fruit and Vegetable Intake among Schoolchildren in Burkina Faso.

The health benefits of fruits and vegetables are well-documented. Those rich in provitamin A carotenoids are good sources of vitamin A. This cross-sectional study indirectly assessed fruit and vegetable intakes using serum carotenoids in 193 schoolchildren aged 7 to 12 years in the Western part of Burkina Faso. The mean total serum carotenoid concentration was 0.23 ± 0.29 µmol/L, which included α- and ß-carotene, lutein, and ß-cryptoxanthin, and determined with serum retinol concentrations in a single analysis with high performance liquid chromatography. Serum retinol concentration was 0.80 ± 0.35 µmol/L with 46% of children (n = 88) having low values <0.7 µmol/L. Total serum carotene (the sum of α- and ß-carotene) concentration was 0.13 ± 0.24 µmol/L, well below the reference range of 0.9⁻3.7 µmol carotene/L used to assess habitual intake of fruits and vegetables. Individual carotenoid concentrations were determined for α-carotene (0.01 ± 0.05 µmol/L), ß-carotene (0.17 ± 0.24 µmol/L), ß-cryptoxanthin (0.07 ± 0.06 µmol/L), and lutein (0.06 ± 0.05 µmol/L). These results confirm the previously measured high prevalence of low serum vitamin A concentrations and adds information about low serum carotenoids among schoolchildren suggesting that they have low intakes of provitamin A-rich fruits and vegetables.

Dietary patterns and physical inactivity, two contributing factors to the double burden of malnutrition among adults in Burkina Faso, West Africa.

A population-based cross-sectional study was carried out in the northern neighbourhoods of Ouagadougou (Burkina Faso), to examine the relationship of nutritional deficiencies and cardiometabolic risk factors (CMRF) with lifestyle in adults. We randomly selected 330 households stratified by income tertile. In each income stratum, 110 individuals aged 25-60 years and having lived in Ouagadougou for at least 6 months were randomly selected. We performed anthropometric, dietary intake and physical activity measurements, and blood sample collection. Cluster analysis of dietary intake identified two dietary patterns: 'urban' (29 % of subjects) and 'traditional' (71 %). The 'urban' cluster exhibited a higher intake of fat and sugar, whereas a higher intake of plant protein, complex carbohydrate and fibre was observed in the 'traditional' pattern. Female sex, low income and lack of education were associated with the 'traditional' cluster, as well as Fe and vitamin A deficiency. CMRF prevalence (abdominal obesity, hypertension, hyperglycaemia, dyslipidaemia) was similar in both clusters. Subjects in the 'traditional' cluster spent more time in physical activity and had less sedentary time than those in the 'urban' cluster. 'Traditional' dietary pattern, low income, female sex and sedentary time were significant contributing factors to the double burden of malnutrition. The rapid nutrition transition is reflected in this co-occurrence of CMRF and nutritional deficiencies. This stresses the need for prevention strategies addressing both ends of the nutrition spectrum.

Association of high-sensitivity C-reactive protein with cardiometabolic risk factors and micronutrient deficiencies in adults of Ouagadougou, Burkina Faso.

Increasing evidence suggests that high-sensitivity C-reactive protein (hs-CRP) is associated with cardiometabolic risk factors (CMRF) while being also related to micronutrient deficiencies. As part of a project on the double burden of under- and overnutrition in sub-Saharan Africa, we assessed the relationship between hs-CRP and both CMRF and micronutrient deficiencies in a population-based cross-sectional study carried out in the Northern district of Ouagadougou, the capital city of Burkina Faso. We randomly selected 330 households stratified by income tertile. In each income stratum, 110 individuals aged 25-60 years and having lived in Ouagadougou for at least 6 months were randomly selected, and underwent anthropometric measurements and blood sample collection. The prevalence of high hs-CRP was 39.4 %, with no sex difference. Vitamin A-deficient subjects (12.7 %) exhibited significant risk of elevated hs-CRP (OR 2.5; P= 0.015). Serum ferritin was positively correlated with log hs-CRP (r 0.194; P= 0.002). The risk of elevated hs-CRP was significant in subjects with BMI ≥ 25 kg/m² (OR 6.9; 95 % CI 3.6, 13.3), abdominal obesity (OR 4.6; 95 % CI 2.2, 7.3) and high body fat (OR 10.2; 95 % CI 5.1, 20.3) (P< 0.001, respectively). Independent predictors of hs-CRP in linear regression models were waist circumference (ß = 0.306; P= 0.018) and serum TAG (ß = 0.158; P= 0.027). In this sub-Saharan population, hs-CRP was consistently associated with adiposity. Assuming that plasma hs-CRP reflects future risk of cardiovascular events, intervention which reduces CRP, or chronic and acute nutrition conditions associated with it, could be effective in preventing their occurrence particularly in sub-Saharan Africa.

The double burden of malnutrition and cardiometabolic risk widens the gender and socio-economic health gap: a study among adults in Burkina Faso (West Africa).

OBJECTIVE: To document the double burden of malnutrition and cardiometabolic risk factors (CMRF) in adults and its occurrence according to different sociodemographic parameters. DESIGN: Population-based cross-sectional observational study. We first randomly selected 330 households stratified by tertile of the income levels proxy as low, middle and high income. SETTING: Northern district of Ouagadougou, the capital city of Burkina Faso. SUBJECTS: In each income stratum, 110 individuals aged 25-60 years and who had lived permanently in Ouagadougou for at least 6 months were randomly selected, followed with collection of anthropometric, socio-economic and clinical data, and blood samples. RESULTS: The overall obesity/overweight prevalence was 24.2 % and it was twice as high in women as in men (34.1 % v. 15.5 %, P < 0.001). Hypertension, hyperglycaemia and low HDL cholesterol prevalence was 21.9 %, 22.3 % and 30.0 %, respectively, without gender difference. The prevalence of the metabolic syndrome was 10.3 %. Iron depletion and vitamin A deficiency affected 15.7 % and 25.7 % of participants, respectively, with higher rates in women. Coexistence of at least one nutritional deficiency and one CMRF was observed in 23.5 % of participants, and this 'double burden' was significantly higher in women than in men (30.4 % v. 16.1 %, P = 0.008) and in the low income group. CONCLUSIONS: CMRF are becoming a leading nutritional problem in adults of Ouagadougou, while nutritional deficiencies persist. The double nutritional burden exacerbates health inequities and calls for action addressing both malnutrition and nutrition-related chronic diseases.

Effect of an improved local ingredient-based complementary food fortified or not with iron and selected multiple micronutrients on Hb concentration.

OBJECTIVE: To assess the effect of an improved local ingredient-based gruel fortified or not with selected multiple micronutrients (MM) on Hb concentration of young children. DESIGN: In a nutrition centre that we opened in their villages, children received either MM supplement (containing iron, zinc, vitamin A, vitamin C and iodine) with the improved gruel (MMGG) or the improved gruel only (GG), twice daily, 6 d/week, for 6 months. We assessed baseline and endpoint Hb concentration and anthropometric indices. SETTING: Kongoussi, a rural and poor district of Burkina Faso. SUBJECTS: In a community-based trial, we randomly assigned 131 children aged 6-23 months with Hb concentrations in the range of 80-109 g/l into two groups. RESULTS: The groups did not differ significantly at baseline. Mean baseline Hb concentration was 89·2 (sd 6·5) g/l and 90·3 (sd 8·4) g/l in the GG and the MMGG, respectively (P = 0·42). It increased to 104·1 (sd 11·4) g/l in the GG (P < 0·001) and 107·6 (sd 14·7) g/l in the MMGG (P < 0·001). The between-group difference of 3·5 (95 % CI -1·0, 8·1) g/l in mean (sd) endpoint Hb concentration was not significant (P = 0·13). The endpoint anthropometric indices were not different between the groups. CONCLUSIONS: This MM supplement had no additional effect on Hb concentration. Thorough studies are needed to evaluate the actual efficacy of the gruel before its introduction into household routine.

Effect of iron or multiple micronutrient supplements on the prevalence of anaemia among anaemic young children of a malaria-endemic area: a randomized double-blind trial.

OBJECTIVE: To assess the effect of supplementation with iron or multiple micronutrients (MM) on the prevalence of anaemia in a malaria-endemic area. METHODS: A community-based randomized double-blind trial was conducted in rural Burkina Faso, including children aged 6-23 months with haemoglobin (Hb) concentrations of 70-109 g/l who were randomized into an iron group (Fe, n = 96), an iron and zinc group (IZ, n = 100) or an MM group (MM, n = 100), 5 days/week for 6 months. All children were provided with insecticide-treated bednets; those who had a Plasmodium falciparum (PF) positive-smear at baseline and/or at each monthly checking received antimalarial therapy. RESULTS: The mean (SD) endpoint Hb concentration was higher in the MM group [113.2 (13.6) g/l] than in the IZ group [106.3 (15.6) g/l] and the Fe group [107.1 (12.9) g/l] (P = 0.001). Children in the MM group were more likely to recover from anaemia than those in the Fe group [prevalence rate ratios, PRR (95% confidence interval, CI) = 1.62 (1.22-2.15), P < 0.001]. The IZ group did not differ from the Fe group [PRR (95% CI) = 0.94 (0.65-1.35), P = 0.72]. None of the interactions on the effect of supplementation of baseline age (0.13), or baseline height-for-age z-score (P = 0.33), or incident PF parasitemia (P = 0.99), was significant. CONCLUSION: In this malaria-endemic area, in combination with malaria management, the MM supplement was more efficacious than the Fe supplement and the IZ supplement for reducing anaemia. Further investigation into limiting factors and amounts of micronutrients that would be more efficacious for reducing anaemia is recommended.

Major reduction of malaria morbidity with combined vitamin A and zinc supplementation in young children in Burkina Faso: a randomized double blind trial.

BACKGROUND: Vitamin A and zinc are crucial for normal immune function, and may play a synergistic role for reducing the risk of infection including malaria caused by Plasmodium falciparum. METHODS: A randomized, double-blind, placebo-controlled trial of a single dose of 200 000 IU of vitamin A with daily zinc supplementation was done in children of Sourkoudougou village, Burkina Faso. Children aged from 6 to 72 months were randomized to receive a single dose of 200 000 IU of vitamin A plus 10 mg elemental zinc, six days a week (n = 74) or placebo (n = 74) for a period of six months. Cross-sectional surveys were conducted at the beginning and the end of the study, and children were evaluated daily for fever. Microscopic examination of blood smear was done in the case of fever (temperature > or =37.5 degrees C) for malaria parasite detection. RESULTS: At the end of the study we observed a significant decrease in the prevalence malaria in the supplemented group (34%) compared to the placebo group (3.5%) (p < 0.001). Malaria episodes were lower in the supplemented group (p = 0.029), with a 30.2% reduction of malaria cases (p = 0.025). Time to first malaria episode was longer in the supplemented group (p = 0.015). The supplemented group also had 22% fewer fever episodes than the placebo group (p = 0.030). CONCLUSION: These results suggest that combined vitamin A plus zinc supplementation reduces the risk of fever and clinical malaria episodes among children, and thus may play a key role in malaria control strategies for children in Africa.

The positive impact of red palm oil in school meals on vitamin A status: study in Burkina Faso.

BACKGROUND: Vitamin A (VA) deficiency is widespread in sub-Saharan Africa and school-age children are a vulnerable group. In Burkina Faso, the production and consumption of red palm oil (RPO) is being promoted as a food supplement for VA. The objective of the study was to assess the impact on serum retinol of adding RPO to school lunch in two test zones of Burkina Faso. METHODS: Over one school year, 15 ml RPO was added to individual meals 3 times a week in selected primary schools in two sites. Serum retinol was measured with HPLC at baseline and exactly 12 months later to take account of seasonality. A simple pre-post test design was used in the Kaya area (north-central Burkina), where 239 pupils from 15 intervention schools were randomly selected for the evaluation. In Bogandé (eastern Burkina), 24 schools were randomised for the controlled intervention trial: 8 negative controls (G1) with only the regular school lunch; 8 positive controls (G2) where the pupils received a single VA capsule (60 mg) at the end of the school year; and 8 schools with RPO through the school year (G3). A random sample of 128 pupils in each school group took part in the evaluation. RESULTS: In Kaya, serum retinol went from 0.77 +/- 0.37 micromol/L at baseline to 1.07 +/- 0.40 micromol/L one year later (p < 0.001). The rate of low serum retinol (< 0.7 micromol/L) declined from 47.2% to 13.1%. In Bogandé, serum retinol increased significantly (p < 0.001) only in the capsule and RPO groups, going from 0.77 +/- 0.28 to 0.98 +/- 0.33 micromol/L in the former, and from 0.82 +/- 0.3 to 0.98 +/- 0.33 micromol/L in the latter. The rate of low serum retinol went from 46.1 to 17.1% in the VA capsule group and from 40.4% to 14.9% in the RPO group. VA-deficient children benefited the most from the capsule or RPO. Female sex, age and height-for-age were positively associated with the response to VA capsules or RPO. CONCLUSION: RPO given regularly in small amounts appears highly effective in the reduction of VA deficiency. RPO deserves more attention as a food supplement for VA and as a potential source of rural income in Sahelian countries.

Investigation on the improvement of prediction by bootstrap model averaging.

OBJECTIVES: We illustrate a recently proposed two-step bootstrap model averaging (bootstrap MA) approach to cope with model selection uncertainty. The predictive performance is investigated in an example and in a simulation study. Results are compared to those derived from other model selection methods. METHODS: In the framework of the linear regression model we use the two-step bootstrap MA, which consists of a screening step to eliminate covariates thought to have no influence on the response, and a model-averaging step. We also apply the full model, variable selection using backward elimination based on Akaike's Information Criterion (AIC), the Bayes Information Criterion (BIC) and the bagging approach. The predictive performance is measured by the mean squared error (MSE) and the coverage of confidence intervals for the true response. RESULTS: We obtained similar results for all approaches in the example. In the simulation the MSE was reduced by all approaches in comparison to the full model. The smallest values are obtained for bootstrap MA. Only the bootstrap MA and the full model correctly estimated the nominal coverage. The backward elimination procedures led to substantial underestimation and bagging to an overestimation of the true coverage. The screening step of bootstrap MA eliminates most of the unimportant factors. CONCLUSION: The new bootstrap MA approach shows promising results for predictive performance. It increases practical usefulness by eliminating unimportant factors in the screening step.

Diastolic unloading and improved LV pump efficiency early after repair of the insufficient mitral valve.

BACKGROUND: This study aimed to evaluate the acute effect of mitral valve repair (MVR) on LV hemodynamics and geometry in patients with normal ventricular function. METHODS: In 10 patients with severe mitral regurgitation undergoing MVR, pressure-volume relationships were recorded before annuloplasty prior to and after hemodilution and after MVR during stable circulatory condition, using the conductance catheter technique (CC). Analyses were done off-line; volume calibration was based on data obtained after completion of valve repair (mean +/- s.d.). RESULTS: CC showed that only 61 +/- 15 % of left ventricular output was ejected into the systemic circulation, regurgitation volume being 39 +/- 15 %. MVR led to a reduction in LV stroke work index from 4.7 +/- 1.8 mm Hg x l x m (-2) at before valve repair to 2.2 +/- 1.0 mm Hg x l x m (-2) after surgery at unchanged cardiac index. LV diastolic filling parameters improved: LV relaxation time constant tau decreased from 52 +/- 15 to 37 +/- 11 ms and dP/dt (min) increased from - 873 +/- 231 to - 1286 +/- 283 mm Hg x s (-1). CONCLUSIONS: Despite cardioplegic arrest, MVR leads to acute improvement of diastolic LV function early after the operation. This may explain why valve repair has an acute positive effect in patients with impaired LV function.

Extended resection of a chest wall desmoid tumour with concomitant coronary artery bypass grafting.

We report on the resection of a large desmoid tumour of the anterior chest wall in a 65-year-old male patient. The patient had a coronary artery bypass operation 2 years prior to the first detection of a tumour. Because the left internal mammary artery bypass to the left anterior descending coronary artery (LAD) was embedded in the tumour mass, it had to be resected together with the tumour. A saphenous vein aorto-coronary bypass to the LAD with an off-pump technique was then performed, and the chest was reconstructed with polypropylene mesh and a latissimus dorsi musculocutaneous flap.