Validation of anthropometric and bioelectrical impedance analysis (BIA) equations to predict total body water in a group of Cameroonian preschool children using deuterium dilution method

BACKGROUND: Little information is available on the validity of anthropometry or impedance-based equations for prediction of total body water (TBW) in African children. This study was designed to validate and develop equations to predict total body water in Cameroonian children. METHODS: TBW was measured by deuterium dilution in 102 children between 24 and 60 months of age and compared with the ones predicted by 5 anthropometric and 7 BIA equations. Multiple linear regression analysis was used to develop prediction equations for TBW from anthropometric parameters. RESULTS: Unacceptable discrepancies in the estimates of TBW at individual level were noted with all the equations tested. The following new anthropometry and BIA equations for the estimation of TBW were respectively developed: TBW = 6.488 + 0.434 × sex−0.039 × age + 0.670 × weight−0.081 × MUAC (cm)−0.372 × BMI (adjustedR2= 0.71,RMSE = 3.6), and TBW =−6.206 + 0.0037 × height2/Z−0.041 × age + 0.265 × weight + 0.1214 × height (adjustedR2=0.68, RMSE = 1.4). The cross-validation procedures revealed that the predicted values of TBW compared with measured values are accurate at a group level. CONCLUSION: The current published anthropometric and BIA equations are invalid for the estimation of TBW in Cameroonian preschool children. The newly developed anthropometry or BIA prediction equations are valid for use in Cameroonian children aged 24­60 months

Recovery rate of children with moderate acute malnutrition treated with ready-to-use supplementary food (RUSF) or improved corn-soya blend (CSB+): a randomized controlled trial.

OBJECTIVE: To compare an improved corn-soya blend (CSB+) with a ready-to-use supplementary food (RUSF) to test the hypothesis that satisfactory recovery rate will be achieved with CSB+ or RUSF when these foods provide 50 % of the child's energy requirement, the 50 % remaining coming from usual diet. DESIGN: A comparative efficacy trial study was conducted with moderately wasted children, using a controlled randomized design, with parallel assignment for RUSF or CSB+. Every child received a daily ration of 167 kJ (40 kcal)/kg body weight during 56 d with a follow-up performed every 14 d. Every caregiver received nutrition counselling at enrolment and at each follow-up visit. SETTING: Health districts of Mvog-Beti and Evodoula in the Centre region of Cameroon. SUBJECTS: Eight hundred and thirty-three children aged 6-59 months were screened and eighty-one malnourished children (weight-for-height Z-score between -3 and -2) aged 25-59 months were selected. RESULTS: Of children treated with CSB+ and RUSF, 73 % (95 % CI 59 %, 87 %) and 85 % (95 % CI 73 %, 97 %), respectively, recovered from moderate acute malnutrition, with no significant difference between groups. The mean duration of treatment required to achieve recovery was 44 d in the RUSF group and 51 d in the CSB+ group (log-rank test, P=0·0048). CONCLUSIONS: There was no significant difference in recovery rate between the groups. Both CSB+ and RUSF were relatively successful for the treatment of moderate acute malnutrition in children. Despite the relatively low ration size provided, the recovery rates observed for both groups were comparable to or higher than those reported in previous studies, a probable effect of nutrition education.

Validity of anthropometry- and impedance-based equations for the prediction of total body water as measured by deuterium dilution in Cameroonian haemodialysis patients.

BACKGROUND & AIMS: There is no available information on the validity of anthropometry- and impedance-based equations for predicting total body water (TBW) in Cameroonian haemodialysis patients. This study aimed to validate and develop predictive equations of TBW for Cameroonian haemodialysis patients. METHOD: TBW in 40 Cameroonian haemodialysis patients (28 men and 12 women) was measured by deuterium dilution and compared with the one predicted by 7 anthropometric and 9 BIA equations. Multiple linear regression analysis was used to develop an equation for predicting TBW as measured by deuterium, from anthropometric parameters. RESULTS: Pure errors in predicting TBW showed unacceptable value for all equations tested. In all the cases, unacceptable discrepancies at individual level for clinical purposes were noted. The following equation was developed and showed a better agreement with the deuterium dilution method: TBW = 13.8994 + 0.0017 × Age +0.3190 × Weight +1.8532 × Sex. CONCLUSION: Further development and cross-validation of anthropometric and BIA prediction equations specific to African heamodialysis patient are needed. Meanwhile, the equation developed in this study which provided a better agreement with the isotope dilution could be use for Cameroonian haemodialysis patients.

Body composition of Cameroonian lactating women determined by anthropometry, bioelectrical impedance, and deuterium dilution.

OBJECTIVE: This study compared body composition estimates using deuterium dilution, multiple-frequency bioelectrical impedance analysis (BIA), and skinfold thickness techniques in a group of Cameroonian lactating women. METHODS: Body fat, fat-free mass, and total body water in 44 Cameroonian lactating women (2.63 ± 1.31 mo postpartum) were assessed by deuterium dilution, the Siri or black-specific derived Durnin-Womerley equation, and 12 BIA-prediction equations developed in samples of subjects of white, black, black-and-white, or unspecified racial background, respectively. RESULTS: Compared with deuterium dilution, anthropometry and BIA-based predictive equations overestimated body fat by 2.7 to 11.7 kg; thus, fat-free mass and total body water were underestimated. In all cases, the significant biases resulted in large 95% limits of agreement, yielding unacceptable potential bias at the level of the individual. However, the exclusion of suprailiac skinfold in the calculation, yielding to non-significant (P < 0.05) bias, improved the prediction of body composition in Cameroonian lactating women using the Durnin-Womersley and Siri equations. CONCLUSION: It is essential to adjust the Durnin-Womersley equation before using it in the Siri equation for the prediction of body composition in lactating women. Further development and cross-validation of prediction equations from BIA specific to lactating women is needed.

The N-terminal domain of Plasmodium falciparum circumsporozoite protein represents a target of protective immunity.

The N-terminal domain of the circumsporozoite protein (CSP) has been largely neglected in the search for a malaria vaccine in spite of being a target of inhibitory antibodies and protective T cell responses in mice. Thus, in order to develop this region as a vaccine candidate to be eventually associated with other candidates and, in particular, with the very advanced C-terminal counterpart, synthetic constructs representing N- and C-terminal regions of Plasmodium falciparum and Plasmodium berghei CSP were administered as single or combined formulations in mice. We show that the antisera generated against the combinations inhibit sporozoite invasion of hepatocytes in vitro better than antisera against single peptides. Furthermore, two different P. falciparum CSP N-terminal constructs (PfCS22-110 and PfCS65-110) were recognized by serum samples from people living in malaria-endemic regions. Importantly, recognition of the short N-terminal peptide (PfCS65-110) by sera from children living in a malaria-endemic region was associated with protection from disease. Taken together, these results underline the potential of using such fragments as malaria vaccine candidates.