RESUMO
BACKGROUND: Limited data exist on the South African Indian diet despite their high prevalence of non-communicable diseases. This study attempted to determine the dietary quality and patterns of an Indian population in KwaZulu-Natal with reference to the high prevalence of non-communicable disease METHODS: Two-hundred-and-fifty apparently healthy Indians, aged 35-55 years participated in a cross-sectional study where diet was assessed using a validated quantitative food frequency questionnaire. Mean intakes were compared to the World Health Organization goals. Dietary quality was determined by index construction and dietary patterns by factor analysis. RESULTS: The mean daily percentage of energy (%E) from n-3 fatty acids (0.24 %E), dietary fibre (18.4 g/day) and fruit and vegetable intakes (229.4 g/day) were below the World Health Organization goals. Total fat (36.1 %E), polyunsaturated fatty acids (11.8 %E), n-6 fatty acids (11 %E) and free sugars (12.5 %E) exceeded the goals. The means for the deficient index reflected a moderate diet quality whereas, the excess index reflected good diet quality. The Pearson partial correlation coefficients between the deficient index and risk markers were weak whilst, the excess index was inversely correlated with waist circumference for the whole sample. Two factors were identified, based on the percentage of fat that contributed to each food group: factor 1 (meat and fish versus legume and cereal pattern), which accounted for added fat through food preparation; and Factor 2 (nuts and seeds versus sugars and visible fat pattern), which accounted for obvious fat. The medians for waist circumference, blood glucose, cholesterol and triglyceride levels showed significant decreasing trends for factor 1 (p < 0.05). The medians for blood glucose and cholesterol showed significant decreasing trends for factor 2 (p < 0.01). CONCLUSION: A shortfall of fruit and vegetable, fibre and n-3 fatty acid intake in the diet is highlighted. When assessing the diet quality and patterns, guidance on the prudent use of added fats may lead to a healthier lifestyle reducing the prevalence of non-communicable diseases.
Assuntos
Doença Crônica/epidemiologia , Dieta Saudável , Dieta/efeitos adversos , Preferências Alimentares , Cooperação do Paciente , Adulto , População Negra , Doença Crônica/etnologia , Doença Crônica/prevenção & controle , Culinária , Estudos Transversais , Dieta/etnologia , Dieta Saudável/etnologia , Fibras na Dieta/administração & dosagem , Fibras na Dieta/uso terapêutico , Ingestão de Energia/etnologia , Ácidos Graxos Ômega-3/administração & dosagem , Ácidos Graxos Ômega-3/uso terapêutico , Feminino , Preferências Alimentares/etnologia , Frutas , Humanos , Masculino , Pessoa de Meia-Idade , Inquéritos Nutricionais , Cooperação do Paciente/etnologia , Risco , África do Sul/epidemiologia , Verduras , Organização Mundial da SaúdeRESUMO
BACKGROUND: C-reactive protein (CRP), a sensitive marker of inflammation, is an independent predictor of future cardiovascular disease (CVD), which is a major cause of death worldwide. In epidemiological trials, high-fibre intakes have consistently been associated with reduction in CVD risk and CRP levels. OBJECTIVE: The objective of this study was to assess the influence of dietary fibre (DF) on CRP in clinical trials. DATA SOURCES: Databases were searched from the earliest record to April 2008 and supplemented by crosschecking reference lists of relevant publications. STUDY SELECTION: Human adult intervention trials, at least 2 weeks in duration, with an increased and measurable consumption of DF were included and rated for quality. DATA SYNTHESIS: Seven clinical trials were included, and six of these reported significantly lower CRP concentrations of 25-54% with increased DF consumption with dosages ranging between 3.3-7.8 g/MJ. The seventh trial with psyllium fibre supplementation failed to lower CRP levels significantly in overweight/obese individuals. Weight loss and altered fatty acid intakes were present in most of the studies. CONCLUSIONS: In the presence of weight loss and modified saturated, monounsaturated and polyunsaturated fat intakes, significantly lower CRP concentrations (downward arrow 25-54%) are seen with increased fibre consumption (> or =3.3 g/MJ). Mechanisms are inconclusive but may involve the effect of DF on weight loss, and/or changes in the secretion, turnover or metabolism of insulin, glucose, adiponectin, interleukin-6, free fatty acids and triglycerides. Clinical studies of high- and low-fibre diets are needed to explore the potential favourable effects as observed epidemiologically, and to understand individual susceptibility to its anti-inflammatory effect and long-term cardiovascular reduction.
Assuntos
Proteína C-Reativa/metabolismo , Fibras na Dieta/farmacologia , Inflamação/sangue , Adulto , Biomarcadores/sangue , Ensaios Clínicos como Assunto , Gorduras na Dieta , Fibras na Dieta/administração & dosagem , Humanos , Redução de PesoRESUMO
BACKGROUND: The elderly are particularly prone to zinc deficiency because of nutritional and physiological vulnerabilities associated with ageing. A low socio-economic status may further increase the risk of zinc deficiency. This cross-sectional descriptive study assessed the zinc status of an elderly sample in the Vaal region, South Africa. METHODS: The participants were 170 randomly selected elderly people attending a day care centre in Sharpeville. Twenty-four-hour recalls were administered for dietary intake. Weight and height were measured and venous blood samples (n = 67) were drawn to determine biochemical indices. RESULTS: The mean age of the respondents was 71.7 years. The mean +/- SD daily dietary intake for zinc was 11.0 +/- 6.12 mg. Approximately half of the subjects (51.5%) did not reach two-thirds of the recommended dietary allowance for zinc. The mean serum zinc concentration was 61.8 +/- 8.5 microg dL(-1) (9.4 +/- 1.3 micromol L(-1)), with 76.3% of the subjects having zinc values less than the recommended values of 70 microg dL(-1) (10.7 micromol L(-1)). Maize meal was the staple in the diet of approximately half the study population. Although South African maize meal is now fortified with zinc oxide, maize also contains high concentrations of phytate, a known inhibitor of mineral bioavailability. CONCLUSIONS: The results of the present study suggested that zinc deficiency existed in these elderly people. Further research is, however, needed to elucidate possible underlying factors so that appropriate intervention can be implemented.
Assuntos
Envelhecimento/fisiologia , Avaliação Geriátrica , Necessidades Nutricionais , Zinco/administração & dosagem , Zinco/deficiência , Idoso , Idoso de 80 Anos ou mais , Hospital Dia , Feminino , Inquéritos Epidemiológicos , Humanos , Masculino , Rememoração Mental , Pessoa de Meia-Idade , Avaliação Nutricional , Política Nutricional , Prevalência , Classe Social , Fatores Socioeconômicos , África do Sul/epidemiologia , Inquéritos e Questionários , Zinco/sangueRESUMO
In many developing countries with advanced stages of the nutrition transition, the burden of coronary artery disease (CAD) has shifted from the rich to the poor. In South Africa, it is mainly the African population that is experiencing rapid urbanisation and the nutrition transition. It is not clear where the burden of CAD lies in this population group. We tried to answer this question by comparing CAD risk factors within African groups of different socio-economic positions (characterised by total household income and education level) that participated in the THUSA study from 1996 to 1998. The THUSA study was a cross-sectional population- based epidemiological study that examined the influence of urbanisation and related changes in lifestyle and eating patterns on health and disease risk. A total of 1 854 apparently healthy African volunteers were recruited from 37 randomly chosen sites in rural and urban areas of the North-West Province. The results indicated that although the group with the highest socio-economic position had significantly lower serum glucose levels, systolic blood pressures, higher micronutrient intakes and fewer smokers, their sustained increases in total and saturated fat intakes and higher serum total and LDL cholesterol levels, as well as increased body mass indices in men suggested that at that point in time and possibly in the foreseeable future, the burden of CAD will be carried by those Africans with higher socio-economic positions.
Assuntos
Doença da Artéria Coronariana/etiologia , Saúde da População Rural/estatística & dados numéricos , Classe Social , Migrantes/estatística & dados numéricos , Saúde da População Urbana/estatística & dados numéricos , Urbanização , Adulto , Glicemia/análise , Pressão Sanguínea , Índice de Massa Corporal , Doença da Artéria Coronariana/sangue , Doença da Artéria Coronariana/epidemiologia , Doença da Artéria Coronariana/fisiopatologia , Estudos Transversais , Escolaridade , Feminino , Fibrinogênio/análise , Inquéritos Epidemiológicos , Humanos , Renda , Lipídeos/sangue , Masculino , Estado Nutricional , Fatores de Risco , Fumar/efeitos adversos , África do Sul/epidemiologiaRESUMO
OBJECTIVE: To describe an integrated, holistic conceptual framework and research paradigm for a better understanding of the nutrition transition in middle- and low-income countries. MOTIVATION: Current inability effectively to prevent the increasing burden related to changes in food consumption patterns and other health behaviours of populations in transition motivates a new approach for nutrition research and practice. In this proposed approach, broader and integrated dimensions of science and practice may be applied for a better understanding of this complex phenomenon. RESULT: Examples from our own studies are given and quoted to illustrate how results from transdisciplinary studies were used to design an integrated, holistic programme to improve quality of life of people infected with HIV. CONCLUSION: Based on these experiences it is argued that the more holistic and integrated approach should and could lead to more effective and sustainable interventions to prevent the adverse health consequences of the nutrition transition. At the same time such an approach will contribute to efforts to conserve the environment and also human, living and natural resources.
Assuntos
Países em Desenvolvimento , Abastecimento de Alimentos , Infecções por HIV/complicações , Saúde Holística , Distúrbios Nutricionais/epidemiologia , Infecções por HIV/epidemiologia , Humanos , Distúrbios Nutricionais/etiologia , Qualidade de Vida , África do Sul/epidemiologiaRESUMO
OBJECTIVE: To examine the impact of urbanisation on lipid profiles of black South Africans, stratified for HIV status. DESIGN: Cross-sectional population-based survey. SETTING: North West province of South Africa. SUBJECTS: A representative sample of 1,854 apparently healthy volunteers aged > or = 15 years, was recruited from 37 randomly selected sites throughout the province. Subjects were stratified into five urbanisation strata (S): S1 rural villages, S2 farms, S3 informal housing or 'squatter camps' S4 urban townships, and S5 surburban housing. OUTCOME MEASURES: Demographic, physical activity and dietary intake information was collected using validated and culture-sensitive questionnaires. Anthropometric measurements and lipid analyses were determined using standardised methodology. RESULTS: The results revealed significantly lower mean (95% confidence interval) total serum cholesterol (TC) levels in HIV-negative men in S1-S4 compared with S5 (S1 3.91 (3.77-4.05) v. S5 4.79 (4.54-5.04) mmol/l). In HIV-negative women, TC levels were significantly lower in S1-S3 than in S4 and S5 (S1 4.05 (3.94-4.17) v. S5 4.79 (4.59-5.00) mmol/l). The same trends were seen for serum low-density lipoprotein cholesterol (LDLC) and triglycerides and in HIV-positive subjects. Binary logistical analysis indicated that the main factor responsible for the increased TC levels seemed to be increased body mass index (BMI) due to decreased physical activity. CONCLUSIONS: Serum lipid levels increased with urbanisation although they remained within levels recommended for other populations. This may, however, become an important health problem in future if preventive strategies are not implemented. Culturally sensitive physical activity programmes to decrease BMI, targeted at professional men and women, and women in urban townships, seem to constitute the most appropriate intervention.
Assuntos
Soropositividade para HIV/sangue , Lipídeos/sangue , Urbanização , Adulto , Estudos Transversais , Método Duplo-Cego , Feminino , Inquéritos Epidemiológicos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Soroepidemiológicos , África do Sul , População UrbanaRESUMO
The objective of the present study was to assess the relationship between anthropometric measurements and risk factors for non-communicable diseases (NCD) in South African black women. A cross-sectional sample of 1040 apparently healthy black female volunteers, 15-70 years old, was recruited from thirty-seven randomly selected sites in the North West Province, stratified according to level of urbanisation. We analysed the association between BMI, waist:hip (WHR), waist circumference (WC) and skinfold measurements and the following risk factors for NCD: blood pressure, serum lipids, fasting serum glucose and insulin and plasma fibrinogen, by using age-adjusted correlation analyses and stepwise regression analysis. Of the subjects, 28.6 % were obese (BMI>30). After adjustment for age and smoking status, BMI correlated significantly with diastolic blood pressure (r 0.21, P=0.037), serum triacylglycerols (TG) (r 0.30, P=0.003), fasting glucose (r 0.29, P=0.005) and log fasting insulin (r 0.24, P=0.02). There was a significant negative correlation between BMI and HDL-cholesterol (r -0.38, P<0.001). Similar but stronger correlations were found between both WC and WHR and these risk factors. Together with age, WC was a significant predictor of TG, HDL-cholesterol and fasting glucose in regression analysis, while subscapular skinfold was a significant predictor of diastolic blood pressure and fasting glucose concentration. Triceps skinfold was a significant predictor of total serum cholesterol, LDL-cholesterol, plasma fibrinogen and the insulin sensitivity index. Measures of obesity, particularly WC, are associated with the risk for NCD in black South African women, in which a high rate of obesity has been found.
Assuntos
População Negra , Doenças Cardiovasculares/etnologia , Obesidade/etnologia , Adolescente , Adulto , Idoso , Antropometria , Glicemia/análise , Pressão Sanguínea , Constituição Corporal , Índice de Massa Corporal , Doenças Cardiovasculares/etiologia , Estudos Transversais , Feminino , Fibrinogênio/análise , Humanos , Insulina/sangue , Lipídeos/sangue , Pessoa de Meia-Idade , Obesidade/complicações , Obesidade/fisiopatologia , Fatores de Risco , Dobras Cutâneas , África do Sul/epidemiologiaRESUMO
OBJECTIVE: To apply structural equation modelling (SEM) and estimation of variance components to the relative validation data obtained from the quantitative food frequency questionnaire (QFFQ) used in the Transition, Health and Urbanisation in South Africa (THUSA) study. DESIGN: A cross-sectional study. SETTING: A community-based field study in an African population conducted during 1996. SUBJECTS: Residents of the North West Province, South Africa, aged between 15 and 65 years. METHODS: Relative validity of the QFFQ was tested against 7-day weighed food records, 24-hour urinary nitrogen (UN) excretion and estimated basal metabolic rate (BMR). SEM and estimation of variance components were applied to the log-transformed energy, protein, fat, calcium, iron, vitamin A and vitamin C intakes. UN excretion was used as a biomarker in the application of the SEM to protein and estimated BMR to energy intakes. RESULTS: Constant bias (alphaQ) derived by the SEM varied from 0.85 (vitamin C) to 5.8 (energy). There was significant proportional bias for all nutrients except vitamin C. Validation coefficients (ro(Q,T) varied from 0.3 (fat, calcium, iron) to 0.7 (vitamin C). The inclusion of estimated BMR in the SEM for energy increased ro(Q, T) from 0.38 to 0.42. The estimation of variance components gave slightly lower correlations for the relationship between intakes from the QFFQ and the unknown true intake. CONCLUSIONS: Robust statistical methods were successfully applied in a relative validation study for a QFFQ in an African population. Estimated BMR as a biomarker for energy intake produced more meaningful results than UN excretion as a biomarker for protein intake.
Assuntos
Registros de Dieta , Modelos Estatísticos , Inquéritos e Questionários , Adolescente , Adulto , Idoso , Viés , Estudos Transversais , Inquéritos sobre Dietas , Comportamento Alimentar , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nitrogênio/urina , Reprodutibilidade dos Testes , África do SulRESUMO
OBJECTIVE: To develop and assess the reproducibility of a quantitative food frequency questionnaire (QFFQ) sensitive to the culture of the African population of the North West Province, South Africa. DESIGN: A cross-sectional study. SETTING: A community-based field study in a population stratified according to level of urbanization from deep rural to urban upper class. SUBJECTS: A total of 144 (99 women and 45 men) residents of the North West Province, aged between 15 and 65 years. participated in the study. METHODS: A culture-sensitive. 145-item interviewer-administered QFFQ was designed to cover the whole diet. Portion sizes were estimated from a food portion photograph book (FPPB) showing foods in three portion sizes. The QFFQ was administered twice, 6-12 weeks apart. RESULTS: Spearman rank correlation coefficients between the two administrations varied from 0.14 for calcium to 0.75 for alcohol. The mean percentage difference between intakes was 8.5 (standard deviation= 9.9). Energy. protein, carbohydrate and calcium gave differences within 10%. Few significant differences among correlation coefficients or percentage difference for gender, age group or strata of urbanization were present. Bland-Altman plots showed significant proportional bias for protein, fibre and vitamin C. More than 70% of the participants were classified into adjacent quintiles for all nutrients. For food groups, correlation coefficients ranged from 0.25 for milk to 0.45 for vegetable and maize meal groups and 809/a of participants were classified into adjacent quintiles. CONCLUSIONS: The QFFQ appeared to be a reproducible dietary intake assessment instrument.
Assuntos
Diversidade Cultural , Registros de Dieta , Comportamento Alimentar , Nível de Saúde , Inquéritos e Questionários , Adolescente , Adulto , Idoso , Estudos Transversais , Inquéritos sobre Dietas , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , África do SulRESUMO
OBJECTIVE: To determine the relative validity of the culture-sensitive quantitative food frequency questionnaire (QFFQ) developed for the Transition, Health and Urbanisation in South Africa (THUSA) study by 7-day weighed food records, urinary nitrogen excretion and basal metabolic rate (BMR). DESIGN: A cross-sectional study. SETTING: A community-based study in a population stratified according to level of urbanization. SUBJECTS: Residents of the North West Province, South Africa. aged between 15 and 65 years. The weighed food record study comprised 74 participants while 104 participants collected 24-hour urine samples. METHODS: All participants were interviewed using the QFFQ. For the weighed food record study, participants kept detailed weighed food diaries for seven consecutive days. For the urinary nitrogen study, participants made one 24-hour urine collection. Completeness of the urine collections was checked against 240 rug pan-aminobenzoic acid. BMR was estimated by the Schofield equations. RESULTS: Spearman rank correlation coefficients between the QFFQ and weighed food record ranged between 0.14 (fibre) and 0.59 (vitamin C). The QFFQ tended to underestimate intakes compared with the weighed records. Quintile distributions were similar for both methods. The correlation between urinary nitrogen excretion and dietary intake was poor. Possible underreporting was identified for 43% of the participants with the QFFQ and 28% with the weighed food record. CONCLUSIONS: The QFFQ appeared to be a relatively valid instrument for the assessment of dietary intakes of the population of the North West Province. The use of biomarkers in this population was difficult and needs further investigation.
Assuntos
Biomarcadores/urina , Diversidade Cultural , Registros de Dieta , Inquéritos e Questionários , Adolescente , Adulto , Idoso , Metabolismo Basal , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nitrogênio/urina , Reprodutibilidade dos TestesRESUMO
BACKGROUND: Many black persons in South Africa have been subjected to urbanisation and urbanisation has led to a significant increase in diseases of lifestyle. The determinants of hypertension in a population in transition have not been well-defined and there is a pressing need for observational epidemiological studies as well as randomised-controlled trials in populations from Africa. The aim of this study was to investigate the association between blood pressure and factors known to contribute to hypertension. METHODS: The study sample consisted mainly of Setswana speaking people, divided into different levels (strata) of urbanisation, namely stratum 1 (rural) to stratum 5 (urbanized). A total of 1821 black subjects, which included 1040 woman, were recruited and randomly selected from 37 sites from the four geographical quarters of the North West Province of South Africa. The following questionnaires were used: demographic, anthropometric, quantitative food frequency, physical activity and scales to measure psychosocial variables. Biochemical analysis (standardised methods) were done on the serum and plasma of the subjects and the blood pressure was measured with a sphygmomanometer. RESULTS: Of the total sample, 22.8% of the subjects had systolic and 20.7% diastolic blood pressures above 140/90 mm Hg. Males and females from stratum 3 showed the highest rate of hypertension (32.9% systolic and 25.1% diastolic) and stratum 5 the lowest. Blood pressure correlated positively with age, level of urbanisation, WHR (waist:hip ratio) and smoking. In the woman the diastolic blood pressure correlated the best with body mass index (BMI), serum triglycerides, total serum cholesterol, low-density lipoprotein (LDL) cholesterol and s-GGT. Coping strategies, experience of social support, cultural aspects and affect balance are related to blood pressure, especially in the case of women. CONCLUSIONS: It seems that factors associated with urbanisation are related to the manifestation of hypertension in black people of the North West Province, given the highest mean blood pressure in people living in informal settlements, where most newcomers to the urban areas live. Journal of Human Hypertension (2000) 14, 779-787
Assuntos
Hipertensão/etiologia , Adulto , Fatores Etários , Idoso , Feminino , Humanos , Lipídeos/sangue , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Fatores de Risco , UrbanizaçãoRESUMO
Nutritional status and risk factors for chronic diseases, including plasma fibrinogen and its determinants, of Africans in the Northwest Province of South Africa, have been studied in a cross-sectional survey. A representative sample of 1854 "apparently healthy" African men and women volunteers aged 15 years and older was recruited from 37 randomly selected sites throughout the Province and stratified for level of urbanisation. Information was collected using validated and culture-sensitive questionnaires. Fasting blood samples were drawn, and all measurements were done with standardised methodology using appropriate equipment, procedures, and controls. Fibrinogen concentration was measured in citrated plasma with the method of Clauss, using the ACL200 automated system and the international fibrinogen standard. The results revealed a population with a high mean plasma fibrinogen (3.17+/-1.10 g/L for HIV-negative men and 3. 64+/-1.12 g/L for HIV-negative women). Factors known to influence plasma fibrinogen, such as age, gender, smoking habit, and physical activity, were also observed in this population. Young rural men and women had the lowest fibrinogen level. Nasal snuff taking and HIV infection did not influence fibrinogen concentration. Multivariate analyses revealed that lower plasma fibrinogen was associated with low to normal body mass index in women, and with dietary intakes compatible with prudent dietary guidelines in men and women (low intakes of animal protein; trans fatty acids and higher intakes of plant protein; dietary fibre, vitamin E, and iron, and a high dietary P/S ratio). Subjects in the higher quartiles of plasma fibrinogen had significantly lower iron, vitamin E, and vitamin B6 (women) status. Increases in fibrinogen were associated with significant increases in serum lipids. Both under- and overnutrition seem to be associated with high plasma fibrinogen. It is concluded that overall nutritional status, possibly in addition to specific nutrients (and foods), influences plasma fibrinogen.
Assuntos
Fibrinogênio/metabolismo , Estado Nutricional/fisiologia , Adolescente , Adulto , Fatores Etários , Idoso , Índice de Massa Corporal , Estudos Transversais , Dieta/estatística & dados numéricos , Comportamento Alimentar , Feminino , Infecções por HIV , Humanos , Estilo de Vida , Lipídeos/sangue , Masculino , Pessoa de Meia-Idade , Estudos Multicêntricos como Assunto , Inquéritos Nutricionais , População Rural , África do Sul , UrbanizaçãoRESUMO
OBJECTIVE: To develop and test a book of photographs of commonly eaten foods to be used as a visual aid in the description of portion sizes in a large cross-sectional study on the health profile of Africans in transition (THUSA - Transition, Health and Urbanization in South Africa). SETTING: Clinics in the North West Province of South Africa. PARTICIPANTS: One hundred and sixty-nine adult African volunteers DESIGN: Data on commonly eaten foods, preparation methods, recipes and portion sizes were collected in a pilot study. Colour photographs, taken of foods prepared by the researchers and measured into three or four portion sizes, were enlarged and put together in a book. The food portion photograph book (FPPB) was tested by presenting subjects with a portion of real food and asking them to estimate the portion size by matching it with one of the portion photographs. MAIN RESULTS: Of 2959 portions tested, 68% were accurately estimated (estimated weight within 10% of actual weight). Clearly defined solid foods were better estimated than foods that had an amorphous appearance. Accuracy of estimation was not affected by gender, age or education. CONCLUSION: The FPPB was accepted as a useful and convenient visual aid to estimate portion sizes in the cross-sectional dietary intake study.
RESUMO
It is suspected that not only fibrinogen concentration but also the quality of fibrin networks may contribute to cardiovascular risk. Evidence is accumulating that a "prudent" diet may protect against diseases associated with raised clotting factors. The effect of diet on fibrinogen is, however, still controversial. In a previous study performed in our laboratory, it was shown that dietary pectin influences fibrin network architecture in hypercholesterolaemic men without causing any changes in fibrinogen concentration. To elucidate the possible mechanisms, it was necessary to study the possibility that pectin may itself have indirect effects on fibrin network architecture. Pectin is fermented in the gastrointestinal tract to acetate, propionate, and butyrate. In humans, only acetate reaches the circulation beyond the liver. This investigation primarily examined the possibility that pectin may, through acetate, influence fibrin network architecture in vivo. The effects of pectin and acetate supplementation in hypercholesterolaemic subjects were compared. Furthermore, this study also aimed at describing the possible in vitro effects of acetate on fibrin network architecture. Two groups of 10 male hyperlipidaemic volunteers each received a pectin (15 g/day) or acetate (6.8 g/day) supplement for 4 weeks. Acetate supplementation did not cause a significant change in plasma fibrinogen levels. As in the pectin group, significant differences were found in the characteristics of fibrin networks developed in plasma after 4 weeks of acetate supplementation. Fibrin networks were more permeable (from 213+/-76 to 307+/-81 x 10(11) cm2), had lower tensile strength (from 23+/-3 to 32+/-9% compaction), and were more lyseable (from 252+/-11 to 130+/-15 minutes). These results strongly suggest that the effect of pectin on network architecture could partially be mediated by acetate. Progressive amounts of acetate were used in vitro to investigate the possibility that acetate may be directly responsible for changes that occurred in fibrin network architecture in the plasma medium. Results indicated that acetate influenced fibrin network architecture directly. From the results, it seems highly possible that acetate may be responsible in part for the beneficial effects of pectin supplementation in vivo. It is evident that pectin or acetate supplementation can be useful during the treatment or prevention of some clinical manifestations, especially those associated with raised total cholesterol and possibly also plasma fibrinogen.
Assuntos
Antidiarreicos/administração & dosagem , Fibrina/metabolismo , Fibrinogênio/metabolismo , Hipercolesterolemia/sangue , Pectinas/administração & dosagem , Adulto , Dieta , Suplementos Nutricionais , Fibrina/química , Produtos de Degradação da Fibrina e do Fibrinogênio/efeitos dos fármacos , Fibrinogênio/química , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
The major focus of public health programs in developing populations is alleviating undernutrition. In South Africa, however, as in many other developing countries, the African population is experiencing rapid urbanization characterized by a double burden of disease in which noncommunicable diseases (NCD) become more prevalent and infectious diseases remain undefeated. The possible mechanisms through which nutrition contributes to the additional vulnerability to NCD experienced by developing populations are explored and research priorities in this area are identified.
Assuntos
Países em Desenvolvimento , Dieta , Saúde Global , Distúrbios Nutricionais/complicações , Estado Nutricional , Humanos , Fenômenos Fisiológicos da Nutrição , PesquisaRESUMO
OBJECTIVE: To describe the distribution of plasma fibrinogen and relationships with other risk factors for coronary heart disease (CHD) and stroke in the black population of the Cape Peninsula. DESIGN: A cross-sectional survey of a stratified proportional sample of randomly selected black men and women. SETTING: Households in Gugulethu, Langa, Nyanga, New Crossroads, KTC, Old Crossroads and Khayelitsha in the Cape Peninsula, South Africa. SUBJECTS: One subject per household (352 men and 447 women), aged 15-64 years, voluntarily participated. Visitors, pregnant, lactating, ill, mentally retarded and intoxicated subjects were excluded. RESULTS: Mean fibrinogen (thrombin time coagulation method) of men and women were higher than published data for Europeans but slightly lower than values of black Americans. Women aged 45-54 years had the highest level (3.13+/-0.89 g l(-1)) and men aged 15-24 years had the lowest (2.13+/-0.88 g l(-1)). Fifteen per cent of the men and 12% of the women had a level greater than 1 standard deviation of the mean for their age group. Univariate and multivariate analyses revealed significant (P<0.05) positive correlations of fibrinogen with smoking habit, age, body mass index (BMI), total and low-density lipoprotein (LDL) cholesterol, triglycerides, blood pressure and white blood cell count, and significant negative correlations with high-density lipoprotein (HDL) cholesterol, gamma glutamyl transferase (GGT), serum iron and ferritin. The correlations with BMI, serum lipoproteins, iron, ferritin, and GGT suggest that nutritional status and therefore diet influences plasma fibrinogen. CONCLUSION: Relatively high fibrinogen levels, tending to cluster with other, including diet-related, risk factors for CHD and stroke, were observed in black South Africans. It is suggested that fibrinogen may contribute to the high stroke incidence of this population group.
Assuntos
População Negra , Doença das Coronárias/sangue , Doença das Coronárias/etnologia , Fibrinogênio/análise , Acidente Vascular Cerebral/sangue , Acidente Vascular Cerebral/etnologia , Adolescente , Adulto , Fatores Etários , Índice de Massa Corporal , Estudos Transversais , Feminino , Inquéritos Epidemiológicos , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Análise de Regressão , Fatores de Risco , Fatores Sexuais , África do Sul/epidemiologiaRESUMO
The effects of a soluble NSP (fibre) concentrate (SFC) on plasma fibrinogen and plasminogen activator inhibitor-1 (PAI-1), serum and liver lipids and lipoproteins and glucose tolerance were compared with those of bezafibrate (BF), a lipid-lowering drug, in obese baboons (Papio ursinus). The basal diet was a high-fat (37% of total energy), low-NSP (12.4 g/d) Westernized diet, supplemented for 8 weeks with either 20 SFCg/baboon per d or 6.7 mg BF/kg body weight per baboon per d. SFC supplementation significantly lowered PAI-1, total serum cholesterol, HDL-cholesterol and circulating free fatty acid levels. BF significantly lowered total serum cholesterol, but unexpectedly raised serum triacylglycerol levels. Although not statistically significant, the mean liver triacylglycerol concentration of baboons fed on BP was lower than that of baboons fed on SFC supplements. These results suggest that: (1) the mechanism of action of the two cholesterol-lowering treatments differ, with BF having a liver triacylglycerol-lowering effect and (2) the SFC ahd additional beneficial effect on fibrinolysis by lowering PAI-1 levels.
Assuntos
Fibras na Dieta/administração & dosagem , Obesidade/sangue , Obesidade/terapia , Inibidor 1 de Ativador de Plasminogênio/metabolismo , Análise de Variância , Animais , Bezafibrato/uso terapêutico , Dieta , Glucose/metabolismo , Hipolipemiantes/uso terapêutico , Metabolismo dos Lipídeos , Lipídeos/sangue , Lipoproteínas/sangue , Fígado/metabolismo , Masculino , Obesidade/tratamento farmacológico , Papio , Distribuição Aleatória , Triglicerídeos/sangue , Triglicerídeos/metabolismoRESUMO
Fibrinogen is an important risk factor for atherosclerosis, stroke and cardiovascular heart disease (CHD). This risk is increased when associated with a high serum cholesterol. Furthermore, it is also believed that not only fibrinogen concentration, but also the quality of fibrin networks may be an important risk factor for the development of CHD. CHD and stroke as a result of atherosclerosis, plus the related problems of hyperinsulinaemia, hyperlipidaemia and hypertension are strongly related to diet. The "western" diet, defined by low fibre and high fat, sucrose and animal protein intakes, appears to be a major factor leading to death. It has been established that the water-soluble dietary fibre, pectin, significantly decrease the concentration of serum cholesterol levels. Evidence is also accumulating that a diet rich in fibre may protect against diseases associated with raised clotting factors. This investigation studied the possible effects of pectin on fibrinogen levels and fibrin network architecture. Two groups of 10 male hyperlipidaemic volunteers each, received a pectin supplement (15 g/day) or placebo (15 g/day) for 4 weeks. Lipid and fibrin network structure variables were measured at baseline and the end of supplementation. Pectin supplementation caused significant decreases in total cholesterol, low-density lipoprotein cholesterol, apolipoprotein A & B and lipoprotein (a). Significant changes in the characteristics of fibrin networks developed in the plasma of the pectin supplemented group indicated that networks were more permeable and had lower tensile strength. These network structures are believed to be less atherogenic. It is suspected that pectin modified network characteristics by a combination of its effects on metabolism and altered fibrin conversion. This confirms the therapeutic possibilities of dietary intervention. Furthermore, this study also showed that changes in plasma fibrinogen need not be present to induce alterations in fibrin network architecture.
Assuntos
Fibras na Dieta/administração & dosagem , Fibrina/química , Fibrina/metabolismo , Hipercolesterolemia/sangue , Hipercolesterolemia/dietoterapia , Pectinas/administração & dosagem , Adulto , Colesterol/sangue , Doença das Coronárias/etiologia , Doença das Coronárias/prevenção & controle , Método Duplo-Cego , Fibrinogênio/metabolismo , Hemostasia , Humanos , Hipercolesterolemia/complicações , Lipídeos/sangue , Masculino , Pessoa de Meia-Idade , Estrutura Molecular , Fatores de RiscoRESUMO
The recommendation that not more than 300 mg cholesterol be consumed daily to prevent high serum cholesterol levels and coronary heart disease is often used to justify a restriction of egg intake to three or four per week. One egg contains about 200 mg of cholesterol, but eggs are also excellent and relatively inexpensive sources of essential amino acids and certain vitamins. In this paper, the place of eggs in a prudent, cholesterol-lowering diet as a substitute for other animal products, is scrutinised. The extra cholesterol, where considered as the only variable, will increase serum cholesterol levels, but the effect is relatively small. The exclusion of eggs from the diet should be weighed against deprivation of essential nutrients especially in vulnerable groups. While restriction of egg intake in westernised populations seems justifiable, the upper limit of three or four per week may not always be applicable, depending on the overall diet and lipid profile of the individual.
Assuntos
Colesterol na Dieta/efeitos adversos , Ovos/efeitos adversos , Colesterol/análise , Doença das Coronárias/etiologia , Dieta com Restrição de Gorduras , Análise de Alimentos , Humanos , Valor Nutritivo , Fatores de RiscoRESUMO
Two matched groups of healthy non-smoking male volunteers between 18 and 23 years old and with a body mass index of 19-24 kg/m2 were selected from urban whites (n = 15) and from rural Vendas (blacks; n = 17). Fasting venous blood samples were collected between 07.00 and 10.00 h, and a validated food frequency questionnaire was administered. The results showed highly significant differences in dietary patterns. Significant differences were observed with regard to serum cholesterol (p < 0.02), percentage high-density lipoprotein cholesterol (p < 0.02), calculated insulin sensitivity index (p < 0.04), and plasma fibrinogen levels (p < 0.03). Tissue plasminogen activator antigen did not differ significantly. The plasminogen activator inhibitor 1 activity was significantly lower (p < 0.0001) in the Vendas than in the whites. It is concluded that diet may be an important determinant of plasminogen activator inhibitor 1 activity.