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.

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 "Africa's 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.

Educating and training a workforce for nutrition in a post-2015 world.

Nearly all countries in the world today are burdened with malnutrition, manifesting as undernutrition, micronutrient deficiencies, and/or overweight and obesity. Despite some progress, efforts to alleviate malnutrition are hampered by a shortage in number, skills, and geographic coverage, of a workforce for nutrition. Here, we report the findings of the Castel Gandolfo workshop, a convening of experts from diverse fields in March 2014 to consider how to develop the capacity of a global cadre of nutrition professionals for the post-2015 development era. Workshop participants identified several requirements for developing a workforce for nutrition, including an ability to work as part of a multisectoral team; communication, advocacy, and leadership skills to engage decision makers; and a set of technical skills to address future challenges for nutrition. Other opportunities were highlighted that could immediately contribute to capacity development, including the creation of a consortium to link global North and South universities, online training modules for middle managers, and practical, hands-on experiences for frontline nutrition workers. Institutional and organizational support is needed to enable workshop recommendations on education and training to be effectively implemented and sustained. The findings from the Castel Gandolfo workshop can contribute to the delivery of successful nutrition-relevant actions in the face of mounting external pressures and informing and attaining the forthcoming Sustainable Development Goals.

The use of predefined diet quality scores in the context of CVD risk during urbanization in the South African Prospective Urban and Rural Epidemiological (PURE) study.

OBJECTIVE: Urbanization is generally associated with increased CVD risk and accompanying dietary changes. Little is known regarding the association between increased CVD risk and dietary changes using approaches such as diet quality. The relevance of predefined diet quality scores (DQS) in non-Western developing countries has not yet been established. DESIGN: The association between dietary intakes and CVD risk factors was investigated using two DQS, adapted to the black South African diet. Dietary intake data were collected using a quantitative FFQ. CVD risk was determined by analysing known CVD risk factors. SETTING: Urban and rural areas in North West Province, South Africa. SUBJECTS: Apparently healthy volunteers from the South African Prospective Urban and Rural Epidemiological (PURE) study population (n 1710). RESULTS: CVD risk factors were significantly increased in the urban participants, especially women. Urban men and women had significantly higher intakes of both macro- and micronutrients with macronutrient intakes well within the recommended CVD guidelines. While micronutrient intakes were generally higher in the urban groups than in the rural groups, intakes of selected micronutrients were low in both groups. Both DQS indicated improved diet quality in the urban groups and good agreement was shown between the scores, although they seemed to measure different aspects of diet quality. CONCLUSIONS: The apparent paradox between improved diet quality and increased CVD risk in the urban groups can be explained when interpreting the cut-offs used in the scores against the absolute intakes of individual nutrients. Predefined DQS as well as current guidelines for CVD prevention should be interpreted with caution in non-Western developing countries.

Common and rare single nucleotide polymorphisms in the LDLR gene are present in a black South African population and associate with low-density lipoprotein cholesterol levels.

The LDL receptor has an essential role in regulating plasma LDL-C levels. Genetic variation in the LDLR gene can be associated with either lower or moderately raised plasma levels of LDL-C, or may cause familial hypercholesterolemia. The prevalence of single-nucleotide polymorphisms (SNPs) in the LDLR in the black South African population is not known and therefore, we aimed to determine the genotypic variation of the LDLR in the study population as well as to define the association of the different genotypes with plasma LDL-C levels. A random selection of 1860 apparently healthy black South African volunteers aged 35-60 years was made in a cross-sectional study. Novel SNPs were identified in a subset of 30 individuals by means of automated sequencing before screening the entire cohort by means of the Illumina VeraCode GoldenGate Genotyping Assay on a BeadXpress Reader system. Twenty-five SNPs were genotyped, two of which were novel. A very rare SNP, rs17249141, in the promoter region was significantly associated with lower levels of LDL-C. Four other SNPs (rs2738447, rs14158, rs2738465 and rs3180023) were significantly associated with increased levels of LDL-C. We can conclude that some of the various SNPs identified do indeed associate with LDL-C levels.

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.

Evidence that fibrinogen γ' regulates plasma clot structure and lysis and relationship to cardiovascular risk factors in black Africans.

Fibrinogen γ' is known to influence fibrin clot structure in purified experimental models, but little is known regarding its influence on clot structure in plasma. Furthermore, the environmental and biological factors that affect its concentration are poorly described. We analyzed fibrinogen γ', total fibrinogen concentration, and fibrin clot structure in 2010 apparently healthy black South Africans and related them to traditional cardiovascular disease (CVD) risk factors. Fibrinogen γ' generally increased with increasing fibrinogen concentration, but a decreased γ'/total fibrinogen ratio was found at the highest total fibrinogen concentrations. Clot maximum absorbance increased with total fibrinogen and fibrinogen γ', but decreased with γ'/total fibrinogen ratio. Clot lysis time showed a stronger relationship with fibrinogen γ' than with total fibrinogen, whereby increased fibrinogen γ' delayed clot lysis. CVD risk factors (excluding fibrinogen) explained 20% and 3%, respectively, of the variance in fibrinogen γ' and the γ'/total fibrinogen ratio, with C-reactive protein making the biggest contribution. More than 50% of the variance in fibrinogen γ' and γ'/total fibrinogen ratio is explained by factors other than total fibrinogen or other traditional CVD risk factors. Our data show that fibrinogen γ' modulates plasma clot structure and fibrinolysis and is also influenced by factors other than fibrinogen.

Field-testing of guidance on the appropriate labelling of processed complementary foods for infants and young children in South Africa.

There is a lack of formal guidance from international normative bodies on the appropriate marketing of processed complementary foods. Such guidance is necessary to protect and promote optimal infant and young child feeding practices. The aim of this study was to field-test, in South Africa, the interim guidance provided by the Maternal, Infant and Young Child Nutrition Working Group's Draft Guide for Marketing Complementary Foods as a potential tool for use by manufacturers and national governments for guiding the appropriate labelling (as a subset of appropriate marketing practices) of complementary foods. This guidance was used to develop a checklist of questions and criteria for each possible answer, which was tested using a comprehensive database of labels from products purchased in South Africa from June to August 2011. One hundred and sixty product labels of 35 manufacturers were analysed, none of which complied with all checklist criteria. Fifty-six (35%) labels did not provide an appropriate age of introduction while 37 (23%) used images of infants appearing younger than 6 months. Nineteen (12%) labels suggested a daily ration too large for a breastfed child, and 32 (20%) potentially promote the manufacturer's infant formula. Only 58 (36%) labels were easy to read. The majority (69% and 92%) of labels provided instructions for safe and appropriate preparation/use and storage, respectively. The Draft Guide for Marketing Complementary Foods was found to be a useful tool for guiding the appropriate labelling of complementary foods, although some changes and additions are recommended to improve understanding, ease of use and to minimise the subjective interpretation of the guidance.

In black South Africans from rural and urban communities, the 4G/5G PAI-1 polymorphism influences PAI-1 activity, but not plasma clot lysis time.

Data on genetic and environmental factors influencing PAI-1 levels and their consequent effect on clot lysis in black African populations are limited. We identified polymorphisms in the promoter area of the PAI-1 gene and determined their influence on PAI-1act levels and plasma clot lysis time (CLT). We also describe gene-environment interactions and the effect of urbanisation. Data from 2010 apparently healthy urban and rural black participants from the South African arm of the PURE study were cross-sectionally analysed. The 5G allele frequency of the 4G/5G polymorphism was 0.85. PAI-1act increased across genotypes in the urban subgroup (p = 0.009) but not significantly in the rural subgroup, while CLT did not differ across genotypes. Significant interaction terms were found between the 4G/5G polymorphism and BMI, waist circumference and triglycerides in determining PAI-1act, and between the 4G/5G polymorphism and fibrinogen and fibrinogen gamma prime in determining CLT. The C428T and G429A polymorphisms did not show direct relationships with PAI-1act or CLT but they did influence the association of other environmental factors with PAI-1act and CLT. Several of these interactions differed significantly between rural and urban subgroups, particularly in individuals harbouring the mutant alleles. In conclusion, although the 4G/5G polymorphism significantly affected PAI-1act, it contributed less than 1% to the PAI-1act variance. (Central) obesity was the biggest contributor to PAI-1act variance (12.5%). Urbanisation significantly influenced the effect of the 4G/5G polymorphism on PAI-1act as well as gene-environment interactions for the C428T and G429A genotypes in determining PAI-1act and CLT.

Plasma clot lysis time and its association with cardiovascular risk factors in black Africans.

Studies in populations of European descent show longer plasma clot lysis times (CLT) in patients with cardiovascular disease (CVD) than in controls. No data are available on the association between CVD risk factors and fibrinolytic potential in black Africans, a group undergoing rapid urbanisation with increased CVD prevalence. We investigated associations between known CVD risk factors and CLT in black Africans and whether CLTs differ between rural and urban participants in light of differences in CVD risk.Data from 1000 rural and 1000 urban apparently healthy black South Africans (35-60 years) were cross-sectionally analysed.Increased PAI-1(act), BMI, HbA1c, triglycerides, the metabolic syndrome, fibrinogen concentration, CRP, female sex and positive HIV status were associated with increased CLTs, while habitual alcohol consumption associated with decreased CLT. No differences in CLT were found between age and smoking categories, contraceptive use or hyper- and normotensive participants. Urban women had longer CLT than rural women while no differences were observed for men.CLT was associated with many known CVD risk factors in black Africans. Differences were however observed, compared to data from populations of European descent available in the literature, suggesting possible ethnic differences. The effect of urbanisation on CLT is influenced by traditional CVD risk factors and their prevalence in urban and rural communities.

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.

Fibrinogen concentration and its role in CVD risk in black South Africans--effect of urbanisation.

The aim of this study was to investigate correlates of fibrinogen concentration in black South Africans, as well as its association with cardiovascular disease (CVD) risk and whether urbanisation influences this association. A total of 1,006 rural and 1,004 urban black South Africans from the PURE study were cross-sectionally analysed. The association of fibrinogen with CVD risk was determined by investigating the association of fibrinogen with other CVD risk markers as well as with predicted CVD risk using the Reynolds Risk score. The rural group had a significantly higher fibrinogen concentration than the urban group, despite higher levels of risk factors and increased predicted CVD risk in the urban group. Increased levels of CVD risk factors were, however, still associated with increased fibrinogen concentration. Fibrinogen correlated significantly, but weakly, with overall predicted CVD risk. This correlation was stronger in the urban than in the rural group. Multiple regression analysis showed that a smaller percentage of the variance in fibrinogen is explained by the traditional CVD risk factors in the rural than in the urban group. In conclusion, fibrinogen is weakly associated with CVD risk (predicted overall risk as well with individual risk factors) in black South Africans, and is related to the degree of urbanisation. Increased fibrinogen concentration, in black South Africans, especially in rural areas, is largely unexplained, and likely not strongly correlated with traditional CVD-related lifestyle and pathophysiological processes. This does, however, not exclude the possibility that once increased, the fibrinogen concentration contributes to future development of CVD.

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.

The effect of ethanol and its metabolism on fibrinolysis.

The role of ethanol metabolism in possible haemostatic cardioprotective effects has not yet been determined. To this end, we investigated the effect of a moderate dose of ethanol (35 g) and its metabolism, on haemostatic variables over 14 hours (h). Eighteen Caucasian males participated in a placebo-controlled, randomised, cross-over study. Blood was collected prior to alcohol consumption, and at 10 time points for 14 h. Blood ethanol peaked at 1 h and was cleared after 8 h following ethanol consumption, significantly increasing plasma acetate (p=0.0028). Ethanol did not influence the coagulation factors significantly. PAI-1act increased (p<0.0001) and tPAact (p=0.047) decreased following alcohol consumption, reaching maximum (0.69 to 22.2 IU/ml) and minimum (0.88 to 0.33 IU/ml) levels at 5 h, respectively. Significantly increased plasma clot lysis times (46.8 to 67.6 minutes) and reduced global fibrinolytic capacity of whole blood, measured as D-dimer production during incubation of blood clots (2.26 to 0.29 µg/ml), were found at 5 h. Except for PAI-1act (borderline significance; p=0.05), there was no significant difference in the fibrinolytic markers between the two groups the following morning. Moderate ethanol consumption resulted in a significant temporary fibrinolysis inhibition. Any protective effects of moderate ethanol consumption on cardiovascular disease do not appear to be due to improvement in fibrinolytic potential within the first 14 h following consumption. The use of global fibrinolytic assays is recommended for determining the true effect of ethanol on fibrinolysis.

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.

Measuring the glycemic index of foods: interlaboratory study.

BACKGROUND: Many laboratories offer glycemic index (GI) services. OBJECTIVE: We assessed the performance of the method used to measure GI. DESIGN: The GI of cheese-puffs and fruit-leather (centrally provided) was measured in 28 laboratories (n=311 subjects) by using the FAO/WHO method. The laboratories reported the results of their calculations and sent the raw data for recalculation centrally. RESULTS: Values for the incremental area under the curve (AUC) reported by 54% of the laboratories differed from central calculations. Because of this and other differences in data analysis, 19% of reported food GI values differed by >5 units from those calculated centrally. GI values in individual subjects were unrelated to age, sex, ethnicity, body mass index, or AUC but were negatively related to within-individual variation (P=0.033) expressed as the CV of the AUC for repeated reference food tests (refCV). The between-laboratory GI values (mean+/-SD) for cheese-puffs and fruit-leather were 74.3+/-10.5 and 33.2+/-7.2, respectively. The mean laboratory GI was related to refCV (P=0.003) and the type of restrictions on alcohol consumption before the test (P=0.006, r2=0.509 for model). The within-laboratory SD of GI was related to refCV (P<0.001), the glucose analysis method (P=0.010), whether glucose measures were duplicated (P=0.008), and restrictions on dinner the night before (P=0.013, r2=0.810 for model). CONCLUSIONS: The between-laboratory SD of the GI values is approximately 9. Standardized data analysis and low within-subject variation (refCV<30%) are required for accuracy. The results suggest that common misconceptions exist about which factors do and do not need to be controlled to improve precision. Controlled studies and cost-benefit analyses are needed to optimize GI methodology. The trial was registered at clinicaltrials.gov as NCT00260858.

Beliefs of South Africans regarding food and cardiovascular health.

OBJECTIVES: To investigate the beliefs of South African metropolitan adults regarding the importance of influencing cardiovascular health by eating certain food types, and to compare these beliefs between different race, living standards, age and gender groups. DESIGN: Randomised cross-sectional study. Trained fieldworkers administered questionnaires by conducting face-to-face interviews with consumers. SUBJECTS: Two thousand South Africans (16 years and older) were randomly selected from metropolitan areas in South Africa. The data were weighted to be representative of the total South African metropolitan population (N = 10695000) based on gender, age and race distribution. RESULTS: The majority (94%) of the population indicated that it is important to influence cardiovascular risk-related health issues by eating certain food types, especially the higher LSM (Living Standard Measure) groups within the different race groups. Weight loss was considered the least important (61% indicated that it is important) compared with cholesterol lowering (80%), blood pressure (89%), diabetes (86%) and healthy blood vessels (89%). In the higher LSM groups (7-10) higher proportions of respondents agreed than in the lower LSM groups (2 and 3). No differences were seen in responses between different gender, race and age groups. CONCLUSIONS AND RECOMMENDATIONS: This study shows that the metropolitan South African adult population considers the influence on cardiovascular health by eating certain food types to be important. However, modifying weight loss by eating certain food types was considered less important.

Effects of a high walnut and high cashew nut diet on selected markers of the metabolic syndrome: a controlled feeding trial.

We investigated the effects of a high walnut diet and a high unsalted cashew nut diet on selected markers of the metabolic syndrome. In a randomized, parallel, controlled study design, sixty-four subjects having the metabolic syndrome (twenty-nine men, thirty-five women) with a mean age of 45 (sd 10) years and who met the selection criteria were all fed a 3-week run-in control diet. Hereafter, participants were grouped according to gender and age and then randomized into three groups receiving a controlled feeding diet including walnuts, or unsalted cashew nuts or no nuts for 8 weeks. Subjects were required to have lunch at the metabolic ward of the Nutrition Department of the North-West University (Potchefstroom Campus). Both the walnut and the unsalted cashew nut intervention diets had no significant effect on the HDL-cholesterol, TAG, total cholesterol, LDL-cholesterol, serum fructosamine, serum high-sensitivity C-reactive protein, blood pressure and serum uric acid concentrations when compared to the control diet. Low baseline LDL-cholesterol concentrations in the cashew nut group may have masked a possible nut-related benefit. Plasma glucose concentrations increased significantly (P = 0.04) in the cashew nut group compared to the control group. By contrast, serum fructosamine was unchanged in the cashew nut group while the control group had significantly increased (P = 0.04) concentrations of this short-term marker of glycaemic control. Subjects displayed no improvement in the markers of the metabolic syndrome after following a walnut diet or a cashew nut diet compared to a control diet while maintaining body weight.

The effects of high walnut and cashew nut diets on the antioxidant status of subjects with metabolic syndrome.

BACKGROUND: Nut consumption is associated with a protective effect against coronary heart disease, partly due to its high antioxidant content. It is hypothesized that the inclusion of nuts in the diet will improve the antioxidant status of subjects with metabolic syndrome who may be vulnerable to impaired antioxidant status. AIM: The effects of high cashew nut and high walnut diets on the antioxidant status of subjects with metabolic syndrome are investigated. METHODOLOGY: Sixty-four volunteers (29 male and 35 female, 45 +/- 10y) with metabolic syndrome (diagnosed by using the ATP III criteria) received a prudent control diet, prepared in the metabolic kitchen of the North-West University, Potchefstroom campus (NWU-PC) for a period of 3 weeks (run-in). The participants were grouped according to gender and age and randomized into three groups, receiving either the walnut, cashew nut or the control diets for 8 weeks, while maintaining a stable body weight. Nuts provided 20% of daily energy intake. Fasting blood samples were taken after the run-in period (baseline) and at the end of the intervention period and analyzed for various antioxidant capacity markers. RESULTS: The oxygen radical absorbance capacity (ORAC) of the walnut and cashew nut diets were significantly higher than the control diet. Despite this, the walnut and cashew nut diets had no significant effects on serum ORAC, reduced (GSH), oxidized (GSSG) glutathione, GSH:GSSG or diacron reactive metabolites (dRom) (total oxidant status) levels compared to the control group. However, all three groups showed significant improvements in antioxidant status from baseline to end (GSSG and dRom levels decreased; GSG:GSSG ratio and ORAC levels increased). This may be due to a general increased antioxidant intake from the prudent diet compared to the habitual diets. CONCLUSION: Although the inclusion of walnuts and cashew nuts into a prudent diet resulted in an increased antioxidant capacity (ORAC) of the nut diets, compared to the control diet, it did not improve the serum antioxidant profiles of subjects with metabolic syndrome.

Glycation of fibrinogen in uncontrolled diabetic patients and the effects of glycaemic control on fibrinogen glycation.

INTRODUCTION: Evidence exists for a relationship between glycaemic control and macrovascular disease. Non-enzymatic glycation of proteins may explain this relationship in part. We investigated the effect of blood glucose control, under out-patient conditions, on fibrinogen glycation as well as the relationship between glycated fibrinogen and glycaemic control using a new sensitive method for the measurement of glycated fibrinogen. MATERIALS AND METHODS: Blood samples were taken from twenty subjects with uncontrolled Type 2 diabetes (HbA1c>7%) to determine the levels of glycation. The subjects were then treated with insulin in order to control blood glucose. Twenty age and BMI matched non-diabetic subjects were included as a reference group. RESULTS: The subjects with diabetes 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). After control of blood glucose, fibrinogen glycation was reduced significantly in the subjects with diabetes (7.84 to 5.24 mol glucose/mol fibrinogen; p<0.0002). The change in glycation during the intervention correlated significantly with the change in capillary glucose in the diabetic group (r=0.6, p=0.005). Fibrinogen glycation was comparable to HbA1c in predicting glycaemic control (p=0.54). Fibrinogen glycation correlated best with the average fasting capillary glucose of the preceding 5-8 days (r=0.54, p=0.014). CONCLUSION: We conclude that glucose control under out-patient conditions decreases fibrinogen glycation in subjects with Type 2 diabetes and that glycated fibrinogen compares well with HbA1c in its relation to glycaemic control.

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.