Namukolo Covic

Glycaemic control improves fibrin network characteristics in type 2 diabetes – A purified fibrinogen model

Diabetic subjects have been shown to have altered fibrin network structures. One proposed mechanism for this is non-enzymatic glycation of fibrinogen due to high blood glucose. We investigated whether glycaemic control would result in altered fibrin network structures due to decreased fibrinogen glycation. Twenty uncontrolled type 2 diabetic subjects were treated with insulin in order to achieve glycaemic control. Twenty age- and body mass index (BMI)-matched non-diabetic subjects were included as a reference group. Purified fibrinogen, isolated from plasma samples was used for analysis. There was a significant decrease in fibrinogen glycation (6.81 to 5.02 mol glucose/mol fibrinogen) with a corresponding decrease in rate of lateral aggregation (5.86 to 4.62) and increased permeability (2.45 to 2.85 x 10(-8) cm(2)) and lysis rate (3.08 to 3.27 microm/min) in the diabetic subjects after glycaemic control. These variables correlated with markers of glycaemic control. Fibrin clots of non-diabetic subjects had a significantly higher ratio of inelastic to elastic deformation than the diabetic subjects (0.10 vs. 0.09). Although there was no difference in median fiber diameter between diabetic and non-diabetic subjects, there was a small increase in the proportion of thicker fibers in the diabetic samples after glycaemic control. Results from SDS-PAGE indicated no detectable difference in factor XIIIa-crosslinking of fibrin clots between uncontrolled and controlled diabetic samples. Diabetic subjects may have altered fibrin network formation kinetics which contributes to decreased pore size and lysis rate of fibrin clots. Achievement of glycaemic control and decreased fibrinogen glycation level improves permeability and lysis rates in a purified fibrinogen model.

The effect of glycaemic control on fibrin network structure of type 2 diabetic subjects

Diabetic subjects have been shown to have altered fibrin network structures. One possible cause may be fibrinogen glycation resulting in altered structure/function properties. We investigated the effect of glucose control on fibrinogen glycation and fibrin network structure in type 2 diabetes. Blood samples were taken from twenty uncontrolled diabetic subjects at baseline to determine the levels of fibrinogen glycation and fibrin network structures. The subjects were then treated with insulin until blood glucose control was achieved before end blood samples were taken. Twenty age- and BMI-matched non-diabetic subjects were included as a reference group. The diabetic subjects had significantly higher mean fibrinogen glycation at baseline than the non-diabetic subjects (7.84 vs. 3.89 mol glucose / mol fibrinogen; p < 0.001). This was significantly reduced during the intervention (7.84 to 5.24 mol glucose / mol fibrinogen; p < 0.0002) in the diabetic group. Both groups had high mean fibrinogen concentrations (4.25 and 4.02 g/l, diabetic and non-diabetic subjects respectively). There was no difference in fibrinogen concentration, porosity, compaction and kinetics of clot formation between the diabetic subjects and non-diabetic subjects at baseline, nor were there any changes during the intervention despite the reduced fibrinogen glycation. Fibrin network characteristics correlated well with fibrinogen but not with any markers of glycaemic control. Improved glycaemic control resulted in decreased fibrinogen glycation but not fibrinogen concentration. It seems as though porosity, compaction and kinetics of clot formation are more related to fibrinogen concentration than fibrinogen glycation in this model.

Strengthening implementation and utilization of nutrition interventions through research: a framework and research agenda

Undernutrition among women and children contributes to almost half the global burden of child mortality in developing countries. The impact of nutrition on economic development has highlighted the need for evidence‐based solutions and yielded substantial global momentum. However, it is now recognized that the impact of evidence‐based interventions is limited by the lack of evidence on the best operational strategies for scaling up nutrition interventions. With the goal of encouraging greater engagement in implementation research in nutrition and generating evidence on implementation and utilization of nutrition interventions, this paper brings together a framework and a broad analysis of literature to frame and highlight the crucial importance of research on the delivery and utilization of nutrition interventions. The paper draws on the deliberations of a high‐level working group, an e‐consultation, a conference, and the published literature. It proposes a framework and areas of research that have been quite neglected, and yet are critical to better understanding through careful research to enable better translation of global and national political momentum for nutrition into public health impact.

Point-of-use micronutrient fortification: lessons learned in implementing a preschool-based pilot trial in South Africa

This current pilot trial assessed the feasibility of implementing a point-of-use (PoU) micronutrient fortification in preschool settings. Preschool children (n = 151) aged 36–79 months were randomized into intervention (n = 76) and control (n = 75) groups, both receiving breakfast maize-porridge with added micronutrient or placebo powder for 52 school days. Process evaluation and early childhood development indicators were used to assess trial feasibility. Process evaluation results showed that the implementation components were feasible and could be delivered with high fidelity. The improvement in hemoglobin concentration in intervention and control groups were not significantly different (P = 0.250). There was medium likelihood for practical significance for the two global cognitive scores assessed: non-verbal index (intervention effects: 7.20; 95% confidence interval: 2.60, 11.81; P = 0.002, effect size: 0.55) and mental processing index (intervention effects: 2.73; 95% confidence interval: 0.25, 5.70; P = 0.072, effect size: 0.36) on the Kaufman Assessment Battery for Children, Second Edition. The lessons from this trial could help in planning/implementing future PoU micronutrient fortification trial among South African preschool children.

Effects of a multi-micronutrient-fortified beverage, with and without sugar, on growth and cognition in South African schoolchildren: a randomised, double-blind, controlled intervention

Little is known about the effects of combined micronutrient and sugar consumption on growth and cognition. In the present study, we investigated the effects of micronutrients and sugar, alone and in combination, in a beverage on growth and cognition in schoolchildren. In a 2 × 2 factorial design, children (n 414, 6-11 years) were randomly allocated to consume beverages containing (1) micronutrients with sugar, (2) micronutrients with a non-nutritive sweetener, (3) no micronutrients with sugar or (4) no micronutrients with a non-nutritive sweetener for 8.5 months. Growth was assessed and cognition was tested using the Kaufman Assessment Battery for Children version II (KABC-II) subtests and the Hopkins Verbal Learning Test (HVLT). Micronutrients decreased the OR for Fe deficiency at the endpoint (OR 0.19; 95% CI 0.07, 0.53). Micronutrients increased KABC Atlantis (intervention effect: 0.76; 95% CI 0.10, 1.42) and HVLT Discrimination Index (1.00; 95% CI 0.01, 2.00) scores. Sugar increased KABC Atlantis (0.71; 95% CI 0.05, 1.37) and Rover (0.72; 95% CI 0.08, 1.35) scores and HVLT Recall 3 (0.94; 95% CI 0.15, 1.72). Significant micronutrient × sugar interaction effects on the Atlantis, Number recall, Rover and Discrimination Index scores indicated that micronutrients and sugar in combination attenuated the beneficial effects of micronutrients or sugar alone. Micronutrients or sugar alone had a lowering effect on weight-for-age z-scores relative to controls (micronutrients - 0.08; 95% CI - 0.15, - 0.01; sugar - 0.07; 95% CI - 0.14, - 0.002), but in combination, this effect was attenuated. The beverages with micronutrients or added sugar alone had a beneficial effect on cognition, which was attenuated when provided in combination.

Inventory on the dietary assessment tools available and needed in africa: a prerequisite for setting up a common methodological research infrastructure for nutritional surveillance, research, and prevention of diet-related non-communicable diseases

abstract Objective: To carry out an inventory on the availability, challenges, and needs of dietary assessment (DA) methods in Africa as a pre-requisite to provide evidence, and set directions (strategies) for implementing common dietary methods and support web-research infrastructure across countries. Methods: The inventory was performed within the framework of the “Africas Study on Physical Activity and Dietary Assessment Methods” (AS-PADAM) project. It involves international institutional and African networks. An inventory questionnaire was developed and disseminated through the networks. Eighteen countries responded to the dietary inventory questionnaire. Results: Various DA tools were reported in Africa; 24-Hour Dietary Recall and Food Frequency Questionnaire were the most commonly used tools. Few tools were validated and tested for reliability. Face-to-face interview was the common method of administration. No computerized software or other new (web) technologies were reported. No tools were standardized across countries. Conclusions: The lack of comparable DA methods across represented countries is a major obstacle to implement comprehensive and joint nutrition-related programmes for surveillance, programme evaluation, research, and prevention. There is a need to develop new or adapt existing DA methods across countries by employing related research infrastructure that has been validated and standardized in other settings, with the view to standardizing methods for wider use.

Association between iron status and white blood cell counts in African schoolchildren of the North-West Province, South Africa

Iron deficiency with or without anemia is associated with increased susceptibility to infection owing to impaired immune function; this study aimed to examine the associations between markers of iron status and white blood cell counts in African schoolchildren. This cross-sectional study is part of the larger BeForMi study done in the North-West province of South Africa. A total of 556 African schoolchildren (aged 7–10 years) were recruited from the three schools participating in the BeForMi multiple micronutrient intervention study. Demographic information of the children was obtained from their parents/caregivers/guardians in the language of choice using validated questionnaires. Anthropometric indices (weight and height), iron status parameters, hematological parameters (hemoglobin (Hb), red blood cell count (RBC), total and differential white blood cell counts) were measured using standard procedures. No significant gender differences were observed in most of the iron markers and hematological parameters except in C-reactive protein (CRP) (p = 0.004) and eosinophils (p = 0.042) which were higher in boys while RBC (p = 0.018) and Hb (p = 0.023) levels were higher in girls. No relationships were observed between the different iron markers and differential white blood cell counts. A positive correlation was observed between serum ferritin (SF) and CRP in girls only (r = 0.336, p < 0.01), and a positive correlation between SF and mean cell volume (MCV) in boys only (r = 0.197, p < 0.01). In both genders, no correlations were observed between the different iron markers and the differential white blood cell counts. The study revealed no associations between iron status and differential white blood cell counts in children that participated in the BeForMi study calling for more studies to be done in the area of the significance of iron supplementation in healthy children.

Studies since 2005 on South African primary schoolchildren suggest lower anaemia prevalence in some regions

Abstract The objective of this study was to report on the iron status of South African primary schoolchildren, as reported in independent studies conducted since the last National Food Consumption Survey-Fortification Baseline (NFCS-FB) in 2005. Internet searches were conducted for cross-sectional and randomised controlled trials that reported on the iron status of South African primary schoolchildren, published after the NFCS-FB of 2005. Search engines that were used included Science Direct, Sabinet, PubMed, EBSCOhost (Academic Search Premier, Health Source and Medline) and Web of Knowledge. The search terms in different combinations were “South Africa”, “children”, “iron”, “anaemia”, “iron deficiency”, “micronutrient”, “malnutrition” and “nutritional status”. Secondary analysis was carried out on the NFCS-FB data on children aged 7-9 years at provincial level. Outcome measures used were haemoglobin (Hb) and serum ferritin. The search identified four independent studies that were conducted in four different provinces: KwaZulu-Natal, North West, Western Cape and Northern Cape. All four were conducted in low socio-economic areas and selected children with poor iron status for intervention purposes. The studies reported an anaemia prevalence lower than that of the NFCS-FB: 11.5% vs. 14.4%, KwaZulu-Natal; 6.9% vs. 27%, North West; 17.2% vs. 18.8%, Western Cape; and 5.4% vs. 22.2%, Northern Cape. Serum ferritin was more difficult to interpret because different cut-off points were used.Anaemia prevalence, based on Hb concentration in primary schoolchildren, might have improved in some regions since the NFCS-FB. Regular national surveys are recommended to ensure that the iron status of South African primary schoolchildren is kept under surveillance.

Applying a transdisciplinary mixed methods research design to explore sustainable diets in rural South Africa

This article describes a conceptual framework for exploring sustainable diets, using a case study example of ongoing research in the Vaalharts region, a rural setting in South Africa. A qualitative research approach is followed with an integrated transdisciplinary mixed methods research design with multiple concurrent components employed during two sequential phases. A successful application of the framework is achieved through a collaborative team effort of researchers with qualitative and quantitative research expertise transcending different disciplines, as well as participation of community members throughout the research process. We demonstrate that transdisciplinary mixed methods research designs are essential to gain a better understanding of the complex concept of sustainable diets.

Acceptability of Novel Small-Quantity Lipid-Based Nutrient Supplements for Complementary Feeding in a Peri-Urban South African Community

Background: Small-quantity lipid-based nutritional supplements (SQ-LNS) may potentially be used for home fortification in poor settings, where low nutrient-dense complementary foods are commonly used for infant feeding. However, they need to be acceptable to succeed. Objective: This study assessed the acceptability of 2 novel, SQ-LNS (A and B) for supplementing complementary foods among infants aged 6 to 12 months in a peri-urban South African community. Methods: Both supplements were soy-based pastes and contained micronutrients and essential fatty acids. In addition, supplement B contained docosahexaenoic acid, arachidonic acid, phytase and l-lysine. Mother–infant pairs were enrolled in a 2-part trial. Part 1 (n = 16) was a test-feeding trial with a crossover randomized design, and a 5-point hedonic scale was used for sensory evaluation (disagree = 1, agree = 5). Part 2 (n = 38) was a 2-week, home-use trial followed by focus group discussions. Results: In part 1, more than 70% of mothers reported a score ≥4 on sensory attributes for both SQ-LNSs indicating that both supplements were well perceived. In part 2, the mean reported consumption over the 2-week period was 65.3% ± 34.2% and 62.0% ± 31.3% of the 20 g daily portion for supplements A and B, respectively. Focus group discussions confirmed a positive attitude toward the supplements in the study population. Conclusion: This study showed acceptance of both SQ-LNSs in terms of sensory characteristics as well as in terms of practicality for home use.