Salimata Wade

Nutritional status of preschool Senegalese children: long-term effects of early severe malnutrition

The prevalence of malnutrition remains high in many developing countries. However, data relating to the long-term effects of severe malnutrition, specifically, serum levels of biochemical indicators of nutritional status, are still scarce in the literature. Hence the present study aimed to investigate the nutritional, biological and growth status of Senegalese preschool children previously hospitalised for severe malnutrition. The study involved twenty-four 7-year-old children who had suffered from marasmus 5 years earlier, twenty-four siblings living in the same household, and nineteen age-matched children living in the centre of Dakar. The siblings were of similar age to the post-marasmic children. Anthropometry, serum biochemical indicators of nutritional status, growth factors, and haematological and mineral parameters were measured. The prevalence of stunting and wasting was the same in the post-marasmic children as in the siblings. Body-fat and fat-free-mass (FFM) deficits in both groups were corroborated by abnormally low concentrations of transthyretin, osteocalcin, insulin-like growth factor (IGF)-1, and insulin-like growth factor-binding protein (IGFBP)-3. FFM was positively and significantly correlated with concentrations of IGF-1 and IGFBP-3. In the post-marasmic children, height for age was also correlated with IGF-1. Of the post-marasmic children, 53 % had Fe-deficiency anaemia, as did 35 % of the siblings and 29 % of the controls. No significant associations were found between the serum concentrations of Ca, Cu, K, Mg, Na, P, Se, Zn and growth retardation. At 5 years after nutritional rehabilitation, the post-marasmic children remained stunted with nutritional indices significantly lower than the control children. However, these children were doing as well as their siblings except for minor infections.

Plasma zinc concentration responds to short-term zinc supplementation, but not zinc fortification, in young children in Senegal

BACKGROUND Simple, low-cost methods are needed to evaluate the effect of zinc-fortification programs. Plasma zinc concentration is a useful biomarker of zinc intake from supplementation, but responses to zinc fortification are inconsistent. OBJECTIVE The objective was to compare the change in plasma zinc concentrations in young children who received zinc from either a liquid supplement or a zinc-fortified complementary food. DESIGN A double-blind intervention trial was conducted in 137 young Senegalese children aged 9-17 mo who were randomly assigned to receive one of the following treatments for 15 d: 1) 30 g dry weight of an iron-fortified cereal porridge and a liquid multivitamin supplement without zinc (control group), 2) the same porridge and multivitamin supplement with 6 mg Zn added to the supplement dose (ZnSuppl group), or 3) the same porridge with added zinc to provide 6 mg Zn per 25 g dry weight of porridge and multivitamin without zinc (ZnFort group). RESULTS Mean (±SD) plasma zinc concentration (μg/dL) increased by 4.7 ± 1.6 (P = 0.004) in the ZnSuppl group, which was significantly greater (P = 0.009) than the mean change in the control group (-1.0 ± 1.6; P = 0.51) and in the ZnFort group (-1.8 ± 1.7; P = 0.29). The latter 2 groups did not differ from each other (P = 0.99). CONCLUSIONS Plasma zinc concentration increased in children who received daily zinc supplementation for 15 d but not in those who received a zinc-fortified complementary food containing a similar amount of zinc. Additional longer-term studies are needed to assess the effect of zinc-fortification programs on zinc-related functional outcomes and the usefulness of plasma zinc as a biomarker of program effect. This trial was registered at www.clinicaltrials.gov as study NCT0094398.

Body composition predicted from skinfolds in African women: a cross-validation study using air-displacement plethysmography and a black-specific equation.

Skinfold thickness (SF) measurements are commonly used for the indirect assessment of body composition. It is necessary to know how large the bias is when using Caucasian SF-based prediction equations Africans, as no specific equations exist. Our first aim was to test the validity of the equation of Durnin & Womersley for predicting body density from SF in Africans. The second aim was to determine the effect of calculating percentage body fat (%BF) from body density using a black-specific formula rather than the Siri equation, thus taking into account the higher fat-free mass (FFM) density in blacks than in whites. A total of 196 African women volunteered. Mean age was 29.5 (sd 8.7) years and mean BMI was 22.5 (sd 4.6) kg/m2. We compared body density values predicted from SF with those measured by air-displacement plethysmography, and %BF values obtained from body density using the Siri equation or the black-specific calculation. The bias (reference minus prediction) was 0.0100 kg/cm3 in body density (P<10(-4)) and 6.5 % BF (P<10(-4)), and the error (sd of the bias) 0.0097 kg/l and 4.5 % BF. With the black-specific equation, the bias was reduced by 1.9 % BF, while error remained similar. As the %BF prediction required an SF-based equation followed by a body density-based calculation, the lack of validity we observed in Africans may be due to known differences between blacks and whites in the distribution of subcutaneous adipose tissue and, as demonstrated, in the FFM density. Equations thus need to be established using SF values specific to Africans.

Serum Osteocalcin Regulation in Protein-Energy Malnourished Children

ABSTRACT: To evaluate bone turnover changes occurring during protein-energy malnutrition, serum osteocalcin, a marker of bone formation, has been studied in healthy control, stunted, and severely malnourished (kwashiorkor and marasmus) Senegalese children. Serum osteocalcin levels were dramatically reduced in stunted, kwashiorkor, and marasmic children compared with control children. In addition serum osteocalcin levels of control children living in Senegal were lower (−46%) than those of African children living in France. Interestingly, serum osteocalcin level was not related to its major known regulators (1α,25-dihydroxycholecalciferol, 25-hydroxycholecalciferol, and PTH) nor to stunting, but was related to serum transthyretin and thyroid hormones concentrations. These data suggest that serum osteocalcin level is related to protein-energy status and that bone formation was affected in apparently healthy and in malnourished Senegalese children. Serum osteocalcin could be a potent tool in the study of the alterations of bone formation in malnutrition.

Effect of food processing on iron availability of African pearl millet weaning foods

The effects of different cereal precooking process (roasting and extrusion cooking) on iron availability and protein digestibility of four African weaning foods were investigated using in vitro methods. In two weaning foods based on pearl millet, cowpea and peanut, the cereal was extruded (A) or roasted (B). In two other weaning foods having a similar composition, a low proportion of milk powder was added and the cereal extruded (C) or roasted (D). The mean +/- SD iron values (mg/100 g) were: A, 5.56 +/- 0.18; B, 9.12 +/- 0.93; C, 5.89 +/- 0.23; D, 9.04 +/- 0.85. When the pearl millet was roasted, the iron content was higher than in the extruded weaning foods (P < 0.01). However, the percent of available iron of the roasted weaning foods was very low (B, 1.64 +/- 0.01; D, 0.91 +/- 0.02). The iron availability of the extruded weaning foods, A and C, was 3.5 times and 6.5 times higher than the corresponding roasted weaning foods, B and D, respectively. This represented 332.4 +/- 4.4 and 375.1 +/- 5.8 micrograms of available iron/100 g for A and C, respectively versus 149.5 +/- 0.9 and 82.2 +/- 1.8 micrograms of available iron/100 g for B and D, respectively. No significant differences in polyphenol contents were found according to the precooking process of the cereal. The extruded weaning foods showed a higher protein digestibility of approximately 10% than the roasted ones (P < 0.05). A positive correlation was found between in vitro iron availability and protein digestibility (r = 0.976, P < 0.02). Despite a high content of iron, the iron availability of roasted pearl millet weaning foods was quite low. Extrusion cooking of the cereal improved the protein digestibility and iron availability of pearl millet weaning foods; however, the amount of available iron remained insufficient to meet the iron requirements of infants whatever the cereal processing.

Plasma Zinc Concentration Increases within 2 Weeks in Healthy Senegalese Men Given Liquid Supplemental Zinc, but Not Zinc-Fortified Wheat Bread

The responsiveness of plasma zinc concentration to zinc fortification is uncertain. Our objective in this study was to determine whether plasma zinc concentration changes in response to consuming zinc-fortified foods or liquid zinc supplements. We conducted a 4-wk double-blind, randomized trial among 132 healthy Senegalese men ≥ 18 y. Participants received 1 of 4 interventions: 1) (control) 200 g/d of wheat bread fortified with iron and folic acid, but not zinc, and a liquid multivitamin supplement without zinc between meals; 2) (zinc supplement) the same bread and the same multivitamin supplement with 15 mg zinc as ZnSO(4) added; 3) (moderate zinc fortification) the same bread cofortified with 7.5 mg zinc as ZnO and the same multivitamin supplement without zinc; or 4) (high zinc fortification) the same bread cofortified with 15 mg zinc as ZnO and the same multivitamin supplement without zinc. Fasting blood samples were collected twice at baseline and at d 15 and 29 of the intervention. There was no significant interaction between group and study day (P = 0.11). However, at d 15, the mean change in plasma zinc concentration in the zinc-supplemented group was greater than in the placebo and fortification groups ( 0.72 μmol/L vs. -0.09 to 0.03 μmol/L; P = 0.05). At d 29 there were no significant group-wise differences. Across all time points, the zinc-supplemented group was the only group where plasma zinc concentration increased from baseline (P = 0.006). These results suggest that plasma zinc concentration may not be a sufficiently sensitive indicator to evaluate short-term responses to zinc fortification.

Validity of impedance-based predictions of total body water as measured by 2H dilution in African HIV/AIDS outpatients.

Measurements of body composition are crucial in identifying HIV-infected patients at risk of malnutrition. No information is available on the validity of indirect body composition methods in African HIV-infected outpatients. Our first aim was to test the validity of fifteen published equations, developed in whites, African-Americans and/or Africans who were or not HIV-infected, for predicting total body water (TBW) from bioelectrical impedance analysis (BIA) in HIV-infected patients. The second aim was to develop specific predictive equations. Thirty-four HIV-infected patients without antiretroviral treatment and oedema at the beginning of the study (age 39 (SD 7) years, BMI 18.7 (SD3.7) kg/m2, TBW 30.4 (SD7.2) kg) were measured at inclusion then 3 and 6 months later. In the resulting eighty-eight measurements, we compared TBW values predicted from BIA to those measured by 2H dilution. Range of bias values was 0.1-4.3 kg, and errors showed acceptable values (2.2-3.4 kg) for fourteen equations and a high value (10.4) for one equation. Two equations developed in non-HIV-infected subjects showed non-significant bias and could be used in African HIV-infected patients. In the other cases, poor agreement indicated a lack of validity. Specific equations developed from our sample showed a higher precision of TBW prediction when using resistance at 1000 kHz (1.7 kg) than at 50 kHz (2.3 kg), this latter precision being similar to that of the valid published equations (2.3 and 2.8 kg). The valid published or developed predictive equations should be cross-validated in large independent samples of African HIV-infected patients.

Physical Activity Level and Sedentary Behaviors among Public School Children in Dakar (Senegal) Measured by PAQ-C and Accelerometer: Preliminary Results

Background: Physical inactivity and sedentary lifestyles are major risk factors of childhood obesity. This study aimed to measure physical activity (PA) levels by accelerometer and Physical Activity Questionnaire for Older Children (PAQ-C) among Senegalese school children and the relation with Body Mass Index (BMI) and body composition. Methodology: 156 pupils 8–11 years old were randomly selected in four elementary public schools of Dakar. BMI z-score was used to categorize children according to their weight status. PA was measured by PAQ-C in the 156 pupils and by accelerometer (Actigraph GT3X+, Pensacola, FL, USA) in a subsample of 42 children. Body composition was determined by deuterium dilution method. Results: PAQ-C results were comparable in the 156 and 42 pupils. The 42 pupils presented a light activity measured by accelerometer, while PAQ-C classified the majority of them (57%; n = 24) in the moderate PA level. Children spent most of their time (min/day) in sedentary activities and light activities than in moderate and intense activity levels. Accumulation of 60 min/day Moderate-to-Vigorous Physical Activity (MVPA) was achieved by 54.8% (n = 23) of the pupils. MVPA decreased in girls in relation to their body fatness. There was a significant difference in MVPA between boys and girls. Similarly, overweight/obese (45 ± 16 min/day) children had lower MVPA than their normal and underweight peers (88 ± 34 and 74 ± 36 min/day, respectively; p = 0.004). Conclusions: The two methods are inconsistent for measuring light and moderate PA levels. Although PAQ-C is an uncomplicated routine method, various activities were not adapted for genuine activities in Senegalese children and therefore needs to be validated in African children.

Validity of bioelectrical impedance analysis in predicting total body water and adiposity among Senegalese school-aged children

Introduction Childhood obesity is currently a serious public health challenge in developing countries. Therefore, an accurate assessment of adiposity is required. The objective of this study was to validate BIA prediction equations for the assessment of total body water and adiposity or percentage of body fat for the first time in Senegalese school-aged children. Methods One-hundred-fifty-one (151) pupils who were 8–11 years old were randomly selected from four public schools in Dakar. The body composition measured by deuterium dilution method (DDM) was used as the reference method and compared to that predicted by BIA using a multi-frequency analyser. Stepwise backward multiple linear regression was performed to calculate TBW and %BF in a subsample, which were then validated in the rest of the sample. The Bland and Altman approach was used to assess the agreement between the two methods (bias and limits of agreement). Results FFM was higher in boys (24.6±6.9 kg) compared to girls (21.2±3.3 kg; P<0.001), and FM was lower in boys: 3.7 kg [0.9–26.4] compared to girls: 4.5 kg [1.7–22.7]. Overall, 11.3% of children presented excess adiposity (%BF >25% in boys, and >30% in girls) and 2.0% were obese according to WHO cut points for obesity (BMI z-score >+2.0). The equations developed were as follows: TBW = 0.376(Height2/Z50)-0.470 (sex) +0.076(weight) +0.065(height)-2.28. %BF = -1.10(height2/Z50) +3.14(sex)+1.57(weight)-4.347. These specific equations showed good precision and a low and non-significant mean bias (0.11 kg, P = 0.279; and 0.19 kg, P = 0.764) for TBW and %BF, respectively. Conclusion The newly developed equations can be used as an accurate and alternative screening tool for the assessment of obesity among children in various settings.

Folate Deficiency and Anemia Among Women of Reproductive Age (15-49 Years) in Senegal: Results of a National Cross-Sectional Survey:

Background: Widely spread throughout the world, folate and iron deficiencies are risk factors for many diseases. However, contrary to iron deficiency and anemia, which have been documented in depth, the prevalence of folate deficiency among women has not been well-studied. Objective: The aim of this study is to determine the prevalence of folate deficiency and anemia and their association among Senegalese women of reproductive age. Methods: A national cross-sectional survey using a stratified 2-stage cluster sampling was conducted. Data were collected from 1012 women (aged 15-49 years). Plasma folate and hemoglobin (Hb), as well as protein markers of subclinical infections, were equally measured. Results: The mean folate concentration was 8.50 nmol/L (8.16-8.85 nmol/L), and 54.8% of the women were folate deficient (<10 nmol/L). Plasma folate concentration of rural women (7.27 nmol/L [6.89-7.68 nmol/L]) and urban women (10.45 nmol/L [9.88-11.05 nmol/L]) was significantly different (P < .0001), the highest concentration being observed in women living in Dakar, the capital of Senegal. The breastfeeding women showed lower plasma folate concentration compared to nonbreastfeeding ones: 6.97 nmol/L (6.37-7.63 nmol/L) versus 9.03 nmol/L (8.61-9.46 nmol/L). Overall, 27% of the women were suffering from inflammation/infections. Mean Hb concentration was 116.86 (1.18) g/L, and 47.63% of the women involved in the study were anemic (pregnant women Hb <110 g/L; nonpregnant Hb <120 g/L). Also, a positive and significant correlation was found between plasma folate and Hb concentrations (r = .07; P = .0167). Conclusions: This study showed a high prevalence of folate deficiency and anemia among Senegalese women (15-49 years), particularly those living in rural settings and breastfeeding women.