RESUMO
The present study reports the effects of a high-fat (HF) diet of over 8 weeks on the Fe status of growing rats. Tissue Fe levels were analysed by atomic absorption spectrophotometry, and whole-body adiposity was measured by dual-energy X-ray absorptiometry. Histopathology and morphometry of adipose tissue were performed. Liver homogenates were used for measuring ferroportin-1 protein levels by immunoblotting, and transcript levels were used for Fe genes measured by real-time PCR. Tissue Fe pools were fit to a compartmental biokinetic model in which Fe was assessed using fourteen compartments and twenty-seven transfer constants (kj,i from tissue 'i' to tissue 'j') adapted from the International Commission on Radiological Protection (ICRP) 69. Ten kj,i were calculated from the experimental data using non-linear regression, and seventeen were estimated by allometry according to the formula ${k_{i,j}} = a \times {M^b}$. Validation of the model was carried out by comparing predicted and analysed Fe pool sizes in erythrocytes, the liver and the spleen. Body adiposity was negatively associated with serum Fe levels and positively associated with liver Fe stores. An inferred increase in Fe transfer from bone marrow to the liver paralleled higher hepatic Fe concentrations and ferritin heavy-chain mRNA levels in the HF diet-fed animals, suggesting that liver Fe accumulation occurred at least in part due to a favoured liver erythrocyte uptake. If this feeding condition was to be prolonged, impaired Fe decompartmentalisation may occur, ultimately resulting in dysmetabolic Fe overload.
Assuntos
Adiposidade , Dieta Hiperlipídica/efeitos adversos , Sobrecarga de Ferro/etiologia , Ferro/metabolismo , Absorciometria de Fóton , Animais , Proteínas de Transporte de Cátions/análise , Modelos Animais de Doenças , Fígado/metabolismo , Ratos , Baço/metabolismoRESUMO
Magnesium is a predominantly intracellular ion and plays an important role in energy metabolism and in the maintenance of energy homeostasis. This study aimed to estimate the dietary intake of magnesium and its association with adiposity parameters in obese women. This cross-sectional study included 125 women, aged between 20 and 50 years, who were divided into two groups: obese group (n = 62) and control group (n = 63). The control group was age-matched. Adiposity parameters determined were weight, body mass index and waist circumference as well as the intake of calories, macronutrients, and magnesium were calculated. The cut-off for obesity was body mass index between 30.0 and 39.9 kg/m2 and for control group was between 18.5 and 24.9 kg/m2 Food intake was calculated using 3-day food records, and energy consumption as well as the intake of macronutrients and magnesium was calculated using the NutWin software version 1.5. The reference values used were the Acceptable Macronutrient Distribution Range for macronutrients and the Estimated Average Requirement (EAR) for magnesium. The average levels of magnesium found in the diet were lower than those recommended (169.1 ± 64.5 mg Mg/day and 158.5 ± 42.9 mg Mg/day, for obese women and control group, respectively) and the differences between the groups were not statistically different (p > 0.05). The correlation analysis indicated that the association between the dietary intake of magnesium and adiposity was not significant. The results of this study indicate that dietary magnesium does not influence the adiposity parameters in obese women.
Assuntos
Magnésio , Obesidade , Adulto , Índice de Massa Corporal , Estudos Transversais , Dieta , Ingestão de Energia , Feminino , Humanos , Magnésio/química , Magnésio/farmacologia , Pessoa de Meia-Idade , Adulto JovemRESUMO
Predictive iron bioavailability (FeBio) methods aimed at evaluating the association between diet and body iron have been proposed, but few studies explored their validity and practical usefulness in epidemiological studies. In this cross-sectional study involving 127 women (18â»42 years) with presumably steady-state body iron balance, correlations were checked among various FeBio estimates (probabilistic approach and meal-based and diet-based algorithms) and serum ferritin (SF) concentrations. Iron deficiency was defined as SF < 15 µg/L. Pearson correlation, Friedman test, and linear regression were employed. Iron intake and prevalence of iron deficiency were 10.9 mg/day and 12.6%. Algorithm estimates were strongly correlated (0.69≤ r ≥0.85; p < 0.001), although diet-based models (8.5â»8.9%) diverged from meal-based models (11.6â»12.8%; p < 0.001). Still, all algorithms underestimated the probabilistic approach (17.2%). No significant association was found between SF and FeBio from Monsen (1978), Reddy (2000), and Armah (2013) algorithms. Nevertheless, there was a 30â»37% difference in SF concentrations between women stratified at extreme tertiles of FeBio from Hallberg and Hulthén (2000) and Collings’ (2013) models. The results demonstrate discordance of FeBio from probabilistic approach and algorithm methods while suggesting two models with best performances to rank individuals according to their bioavailable iron intakes.
Assuntos
Anemia Ferropriva/sangue , Ferritinas/sangue , Aptidão Genética , Ferro da Dieta/sangue , Modelos Biológicos , Adolescente , Adulto , Algoritmos , Anemia Ferropriva/diagnóstico , Anemia Ferropriva/epidemiologia , Disponibilidade Biológica , Biomarcadores/sangue , Brasil/epidemiologia , Estudos Transversais , Feminino , Humanos , Ferro da Dieta/administração & dosagem , Idade Materna , Valor Preditivo dos Testes , Prevalência , Probabilidade , Reprodutibilidade dos Testes , Adulto JovemRESUMO
The role of hepcidin in iron homeostasis in preeclamptic pregnant women is unclear. To test the hypothesis that increased serum iron in women diagnosed with preeclampsia results from decreased production of hepcidin, we performed an observational case-control study in which serum hepcidin concentration, dietary iron intake, hematological indices, iron status, liver function, and inflammatory markers in 18 preeclamptic women and 18 healthy normotensive pregnant women of similar age range were evaluated. Iron intake was established via a food frequency questionnaire, whereas hematological indices, iron status, liver function, and inflammatory markers were assessed using standard protocols. Hematocrit was significantly higher (P = .031) in the preeclamptic group compared with the control, whereas erythropoietin level was significantly lower (P = .003). The pronounced inflammatory status of preeclamptic women was confirmed by significantly higher concentrations of interleukin-6 (P = .001), tumor necrosis factor-α (P < .001), and ferritin (P < .001). Nonetheless, the preeclamptic group exhibited significantly higher serum iron (P = .012) and transferrin saturation (P = .006), and these alterations were accompanied by lower hepcidin levels (P = .047). No significant correlations between hepcidin concentration and iron status parameters were observed in either group. However, a positive and significant correlation between hepcidin concentration and C-reactive protein was observed in the preeclamptic group (r = 0.474; P = .047). We conclude that high serum iron in preeclamptic women is likely caused by low production of hepcidin, thus supporting the hypothesis originally stated.
Assuntos
Proteína C-Reativa/metabolismo , Hepcidinas/sangue , Inflamação/etiologia , Sobrecarga de Ferro/etiologia , Ferro da Dieta/sangue , Ferro/sangue , Pré-Eclâmpsia/sangue , Adolescente , Adulto , Estudos de Casos e Controles , Inquéritos sobre Dietas , Eritropoetina/sangue , Feminino , Ferritinas/sangue , Hematócrito , Homeostase , Humanos , Inflamação/sangue , Interleucina-6/sangue , Sobrecarga de Ferro/sangue , Estado Nutricional , Gravidez , Transferrina/metabolismo , Fator de Necrose Tumoral alfa/sangue , Adulto JovemRESUMO
Magnesium (Mg2+) is a mineral with the ability to influence cell proliferation and to modulate inflammatory/immune responses, due to its anti-inflammatory properties. In addition, mesenchymal stem cells (MSCs) modulate the function of all major immune cell populations. Knowing that, the current work aimed to investigate the effects of Mg2+ enrichment, and its influence on the immunomodulatory capacity of MSCs. Murine C3H/10T1/2 MSCs were cultivated in media with different concentrations of Mg2+ (0, 1, 3 and 5 mM), in order to evaluate the effects of Mg2+ on MSC immunomodulatory properties, cell proliferation rates, expression of NFκB and STAT-3, production of IL-1ß, IL-6, TGF-ß, IL-10, PGE2 and NO, and TRPM7 expression. The results showed that TRPM7 is expressed in MSCs, but Mg2+, in the way that cells were cultivated, did not affect TRPM7 expression. Additionally, there was no difference in the intracellular concentration of Mg2+. Mg2+, especially at 5 mM, raised proliferation rates of MSCs, and modulated immune responses by decreasing levels of IL-1ß and IL-6, and by increasing levels of IL-10 and PGE2 in cells stimulated with LPS or TNF-α. In addition, MSCs cultured in 5 mM Mg2+ expressed lower levels of pNFκB/NFκB and higher levels of pSTAT-3/STAT-3. Furthermore, conditioned media from MSCs reduced lymphocyte and macrophage proliferation, but Mg2+ did not affect this parameter. In addition, conditioned media from MSCs cultured at 5 mM of Mg2+ modulated the production profile of cytokines, especially of IL-1ß and IL-6 in macrophages. In conclusion, Mg2+ is able to modulate some immunoregulatory properties of MSCs.
Assuntos
Citocinas/metabolismo , Magnésio/fisiologia , Células-Tronco Mesenquimais/imunologia , Animais , Ciclo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Meios de Cultivo Condicionados/farmacologia , Citocinas/imunologia , Dinoprostona/metabolismo , Imunomodulação , Linfócitos/citologia , Linfócitos/efeitos dos fármacos , Macrófagos/citologia , Macrófagos/metabolismo , Magnésio/farmacologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Camundongos , NF-kappa B/metabolismo , Óxido Nítrico/metabolismo , Fator de Transcrição STAT3/metabolismo , Canais de Cátion TRPM/metabolismoRESUMO
Magnesium (Mg), an essential ion for the human body, is involved in various enzymatic reactions, particularly those related to energy transfer, storage, and transport. Longitudinal studies show that hypomagnesaemia (Mg serum concentration <0.75 mmol/L) and Mg dietary inadequacy (daily intake < EAR (Estimated Average Requirement) for age/gender) are conditions related to metabolic disorders of the immune and cardiovascular system and often occur in obese and diabetic individuals. Poor eating habits, reduced Mg content in food and water are the main causes of the decrease in Mg intake by the general population. In clinical practice, the serum concentration of this mineral is the most widely used marker for diagnosing deficiency. However, the serum concentration does not reflect the nutritional Mg status since it can be maintained by mobilization of body storage, mainly the bone. Thus, the use of serum concentration as the only routine biomarker of Mg status may hinder the diagnosis of Mg deficiency. In clinical and experimental research, different methods for Mg status assessment are proposed (plasma, erythrocyte, urine), but they are seldom used in clinical routine. In some countries (such as USA and Brazil) the average daily Mg dietary ingestion of more than 60% of the adult population is lower than the Estimated Average Requirement for age and gender, and these data are not too different for individuals with chronic non-communicable diseases. It is unclear whether it is an actual reduction of Mg consumption or if the recommendations are overestimated. If we assume that the recommendations are correct, the question is if this condition constitutes a risk factor for chronic diseases or the hypomagnesemia described in some diseases is a consequence of physiopathological changes. This review has the latest information of human and animal studies about Mg status evaluated from plasma, erythrocyte and urine, dietary inadequacy, and its relation to inflammation and to components of metabolic syndrome.
Assuntos
Humanos , Masculino , Feminino , Magnésio/análise , Magnésio/metabolismo , Magnésio/uso terapêutico , Doença Crônica/prevenção & controle , Resistência à InsulinaRESUMO
OBJECTIVE: To investigate the association between serum unmetabolized folic acid (UMFA) concentrations and folic acid from fortified foods and nutrients known as dietary methyl-group donors (folate, methionine, choline, betaine and vitamins B2, B6 and B12) in participants exposed to mandatory fortification of wheat and maize flours with folic acid. METHODS: Cross-sectional study carried out with 144 healthy Brazilian participants, both sexes, supplement nonusers. Serum folate, UMFA, vitamin B12 and total plasma homocysteine (tHcy) were biochemically measured. Dietary intake was assessed by 2 non-consecutive 24-hour dietary recalls (24-HRs) and deattenuated energy-adjusted nutrient data were used for statistical analysis. RESULTS: Ninety eight (68.1%) participants were women. Median (interquartile range) age was 35.5 (28.0-52.0) years. Elevated serum folate concentrations (>45 nmol/L) were found in 17 (11.8%), while folate deficiency (<7 nmol/L) in 10 (6.9%) participants. No one had vitamin B12 deficiency (<148 pmol/L). An elevated serum UMFA concentration was defined as > 1 nmol/L (90th percentile). UMFA concentrations were positively correlated with folic acid intake and negatively correlated to choline, methionine and vitamin B6 intakes. Participants in the lowest quartile of UMFA concentrations had lower dietary intake of total folate (DFEs) and folic acid, and higher dietary intake of methionine, choline and vitamin B6 than participants in the highest quartile of UMFA. Folic acid intake (OR [95% CI] = 1.02 [1.01-1.04)] and being a male (OR [95% CI] = 0.40 [0.19-0.87) were associated with increased and reduced odds for UMFA concentrations > 0.55 nmol/L (median values), respectively. CONCLUSION: UMFA concentrations were directly influenced by folic acid intake from fortified foods in a healthy convenience sample of adult Brazilians exposed to mandatory flour fortification with folic acid.
Assuntos
Dieta , Farinha , Ácido Fólico/sangue , Alimentos Fortificados , Complexo Vitamínico B/sangue , Adulto , Brasil/epidemiologia , Colina/administração & dosagem , Feminino , Ácido Fólico/administração & dosagem , Deficiência de Ácido Fólico/sangue , Deficiência de Ácido Fólico/epidemiologia , Homocisteína/sangue , Humanos , Masculino , Metionina/sangue , Pessoa de Meia-Idade , Razão de Chances , Prevalência , Riboflavina/administração & dosagem , Triticum , Vitamina B 12/administração & dosagem , Vitamina B 12/sangue , Deficiência de Vitamina B 12/sangue , Deficiência de Vitamina B 12/epidemiologia , Vitamina B 6/administração & dosagem , Complexo Vitamínico B/administração & dosagem , Adulto Jovem , Zea maysRESUMO
The aim of this study was to assess the relationship between magnesium status and oxidative stress in obese and nonobese women. This cross-sectional study included 83 women, aged between 20 and 50 years, who were divided into two groups: the obese group (n = 31) and the control group (n = 52). The control group was age-matched with the obese group. Magnesium intake was monitored using 3-day food records and NutWin software version 1.5. The plasma and erythrocyte magnesium concentrations were determined by flame atomic absorption spectrophotometry. Plasma levels of thiobarbituric acid reactive substances (TBARS) were determined as biomarkers for lipid peroxidation and therefore of oxidative stress. The mean values of the magnesium content in the diet were found to be lower than those recommended, though there was no significant difference between groups (p > 0.05). The mean concentrations of plasma and erythrocyte magnesium were within the normal range, with no significant difference between groups (p > 0.05). The mean concentration of plasma TBARS was higher in obese woman, and the difference between the groups was statistically different (p < 0.05). There was a positive correlation between erythrocyte magnesium and plasma TBARS in the obese group (p = 0.021). Obese patients ingest low dietary magnesium content, which does not seem to affect the plasma and erythrocyte concentrations of the mineral. The study showed a negative correlation between erythrocyte magnesium concentrations and plasma TBARS, suggesting the influence of magnesium status on the parameters of oxidative stress in obese women.
Assuntos
Suplementos Nutricionais , Eritrócitos/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Magnésio , Obesidade/sangue , Estresse Oxidativo/efeitos dos fármacos , Adulto , Estudos Transversais , Feminino , Humanos , Magnésio/administração & dosagem , Magnésio/farmacocinética , Pessoa de Meia-IdadeRESUMO
BACKGROUND: Improvements in the iron status of a population as result of food fortification are expected at the long term. In Brazil, the effectiveness of mandatory flour fortification with iron has been evidenced mostly from surveys on gestational anemia after 1 or 2 years from its implementation, in 2004. Our aim was to assess hemoglobin (Hb) concentrations and the prevalences of anemia and linked erythrocyte morphology patterns among pregnant women in 2006 and 2008.METHODS: The study design was retrospective and cross-sectional. The analysis was based on secondary data in 546medical records from women at the times of their first prenatal attendance in 13 public primary healthcare units of the Butantan Administrative Region from São Paulo (SP), Brazil. Anemia was evaluated from Hb concentration (cut-off <11.0 g/dL) and erythrocyte morphology patterns from mean corpuscular volume (MCV), mean corpuscular Hb concentration (MHC), and red cell distribution widths (RDW). Recorded sociodemographic and obstetric data included maternal age, gestational age, ethnoracial self-classification, and residence type. Student's t tests, analysis of variance, Chi-squared tests, and multiple linear and logistic regressions were employed in the statistical analysis using a significance level of 5 %.RESULTS:The prevalence of anemia was 9.7 % in 2006 and 9.4 % in 2008 (P= 0.922), with no significant difference in mean Hb concentrations (P= 0.159). Normocytosis (normal MVC), normochromia (normal MHC), and anisocytosis (high RDW) were found in most anemia cases, suggesting that the low Hb concentrations resulted from mixed causes. In multiple regression analysis, gestational age at the first prenatal attendance was an independent predictor of low Hb and of having anemia. Moreover, black ethnoracial self-classification was associated with lower Hb. CONCLUSIONS: The prevalence of gestational anemia was low among women in both of the studied periods, representing a mild public health problem. Our results highlight the importance of early prenatal care as a means of reducing gestation-associated risks. The erythrocyte morphology pattern found in most cases of low Hb levels suggests that, besides iron deficiency, hemoglobin pathies and nutritional deficiencies of folate and vitamin B12 are common complicating factors of gestational anemia in our setting.
Assuntos
Humanos , Feminino , Gravidez , Anemia Ferropriva/prevenção & controle , Eritrócitos/metabolismo , Eritrócitos/fisiologia , Cuidado Pré-Natal , Atenção Primária à SaúdeRESUMO
This study assessed the relationship between magnesium status and C-reactive protein concentration in obese and nonobese women. This cross-sectional study included 131 women, aged between 20 and 50 years, who were divided into two groups: obese (n=65) and control (n=66) groups. Magnesium intake was monitored using 3-day food records and NutWin software version 1.5. The plasma, erythrocyte, and urinary magnesium concentrations were determined by flame atomic absorption spectrophotometry. C-reactive protein concentration in serum was measured by immunoturbidimetric assay. The mean values of the magnesium content in the diet were lower than those recommended, though there was no significant difference between groups (p>0.05). The mean concentrations of plasma and erythrocyte magnesium were within the normal range, with no significant difference between groups (p>0.05). Urinary excretion of this mineral was less than the reference values in both groups, with no significant difference (p>0.05). The mean concentration of serum C-reactive protein was within the normal range in both groups, with no significant difference (p>0.05). There was a positive correlation between urinary magnesium and serum C-reactive protein (p=0.015). Obese patients ingest low dietary magnesium content, which seems to induce hypomagnesuria as a compensatory mechanism to keep plasma concentrations of the mineral at adequate levels. The study shows a positive correlation between urinary magnesium concentrations and serum C-reactive protein, suggesting the influence of hypomagnesuria on this inflammatory protein in obese women.
Assuntos
Proteína C-Reativa/metabolismo , Magnésio/sangue , Obesidade/sangue , Adulto , Antropometria , Índice de Massa Corporal , Estudos Transversais , Dieta , Feminino , Humanos , Inflamação/sangue , Magnésio/urina , Pessoa de Meia-Idade , Estado Nutricional , Reprodutibilidade dos Testes , Espectrofotometria Atômica , Adulto JovemRESUMO
BACKGROUND & AIMS: Preeclampsia is responsible for more than one-third of all maternal deaths in Brazil. The objectives of the present study were to evaluate magnesium status and its association with oxidative stress and inflammation in preeclamptic women, and to identify the predictor variables of the disorder. METHODS: The study population consisted of 36 women divided into preeclamptic (n = 18) and control groups (n = 18). The preeclamptic group included women (≥20 weeks of pregnancy) with arterial pressure ≥ 140/90 mmHg and proteinuria >0.3 g/24 h, while the control group comprised pregnant women with no clinical/obstetric complications. Magnesium intake was assessed via a food frequency questionnaire validated for pregnant women in Brazil. Plasma, erythrocyte and urinary magnesium levels were determined by flame atomic absorption spectroscopy, while oxidative stress and inflammatory markers were assessed using standard protocols. Logistic regression analysis was used to identify the predictors of preeclampsia. RESULTS: Preeclamptic and control groups were similar with respect to magnesium intake and urinary excretion, while plasma and erythrocyte magnesium concentrations were higher in the former group. Plasma magnesium was positively correlated with catalase and glutathione peroxidase activities and with concentrations of interleukin-6 and tumor necrosis factor alpha. Regression analysis showed that plasma magnesium and urinary 8-isoprostane were associated with preeclampsia. CONCLUSION: Magnesium status appears to result from homeostatic imbalance and physiological alterations typical of preeclampsia. Increased plasma magnesium and decreased urinary 8-isoprostane were considered predictors of preeclampsia.
Assuntos
Inflamação/sangue , Magnésio/sangue , Estresse Oxidativo , Pré-Eclâmpsia/sangue , Adolescente , Adulto , Biomarcadores/sangue , Biomarcadores/urina , Índice de Massa Corporal , Peso Corporal , Brasil , Estudos de Casos e Controles , Catalase/sangue , Dinoprosta/análogos & derivados , Dinoprosta/urina , Feminino , Glutationa Peroxidase/sangue , Humanos , Interleucina-6/sangue , Modelos Logísticos , Pré-Eclâmpsia/diagnóstico , Gravidez , Fator de Necrose Tumoral alfa/sangue , Adulto JovemRESUMO
The present study investigated the effects of fructo-oligosaccharides (FOS) on the bioavailability of Fe from ferric pyrophosphate (FP), a water-insoluble compound, in Fe-deficient anaemic rats that were subjected to a Hb repletion assay. Male Wistar rats (n 64) were fed adequate or low (8 mg/kg) Fe diets for 15 d followed by 1 or 2 weeks of Fe repletion with diets providing 35 mg Fe/kg as ferrous sulphate (FS), FP or FP that was mixed with 7·5% FOS in the form of yacon flour or Raftilose P95 (RAF), a purified source of FOS. The effects of FOS were observed within the 1st week of the repletion period. Fe bioavailability was improved by FOS supplementation, as measured by Hb regeneration efficiency and hepatic Fe stores, which were more pronounced in the RAF group. Moreover, RAF supplementation resulted in a higher biological value relative to that of the FP group. FOS supplementation resulted in caecal enlargement, in addition to acidification and Fe species redistribution in the caecal contents relative to the control rats. These effects occurred concomitantly with decreased ferroportin (FPN)-1 expression in the caecal mucosa, which was similar in magnitude to that observed in the FS group. Caecum mucosal morphometry was influenced by FOS supplementation, whereas crypt fission and cell proliferation were highest in the caecum of the RAF group. These results reinforce the effects of FOS as Fe bioavailability enhancers in anaemic rats that are sustained by early changes in their caecal environment (decreased mucosal FPN-1 expression and increased Fe absorbability, crypt fission and cellularity).
Assuntos
Anemia Ferropriva/dietoterapia , Proteínas de Transporte de Cátions/metabolismo , Ceco/patologia , Mucosa Intestinal/patologia , Ferro da Dieta/administração & dosagem , Ferro/análise , Oligossacarídeos/uso terapêutico , Anemia Ferropriva/sangue , Anemia Ferropriva/metabolismo , Anemia Ferropriva/patologia , Animais , Brasil , Proteínas de Transporte de Cátions/genética , Ceco/metabolismo , Proliferação de Células , Difosfatos/administração & dosagem , Compostos Ferrosos/administração & dosagem , Alimentos Fortificados , Frutose/análise , Conteúdo Gastrointestinal/química , Hemoglobinas/análise , Ferro/administração & dosagem , Ferro/sangue , Ferro/química , Ferro/metabolismo , Ferro da Dieta/metabolismo , Ferro da Dieta/uso terapêutico , Masculino , Valor Nutritivo , Oligossacarídeos/química , Raízes de Plantas/química , Prebióticos , Ratos Wistar , Traqueófitas/químicaRESUMO
The present study evaluated the influence of magnesium on insulin resistance in obese women. A case-control study involving 114 women on the age between 20 and 50 years old, divided into two groups: control (eutrophic women, n = 59) and case (obese women, n = 55). The analysis of magnesium intake was carried out through the 3-day food record and also NutWin software version 1.5. The plasma, erythrocyte, and urinary magnesium concentrations were determined by flame atomic absorption spectrophotometry. The determinations of serum glucose and serum insulin were performed by enzymatic colorimetric method and chemiluminescence, respectively. The insulin resistance was assessed by homeostasis model assessment insulin resistance (HOMA-IR). The mean values of magnesium intake were lower than those recommended, without difference between groups (p > 0.05). All the patients who were evaluated showed adequate mean concentrations of magnesium in the plasma and erythrocyte. The urinary excretion of this mineral was lower than the reference values in both groups and did not show significant difference (p > 0.05). The values of serum glucose, serum insulin, and HOMA-IR were higher in obese women compared to the control group. A negative correlation was observed between erythrocyte magnesium and glycemic parameters (p < 0.05). Obese patients take in foods with low dietary magnesium content, and they show hypomagnesuria as a compensatory mechanism to keep the plasma concentration of this mineral in adequate levels. The correlation between the erythrocyte magnesium concentration and the parameters of glycemic control suggests the influence of this mineral on the index of insulin resistance in obese women.
Assuntos
Análise de Alimentos , Resistência à Insulina , Magnésio/administração & dosagem , Avaliação Nutricional , Obesidade/metabolismo , Adulto , Estudos de Casos e Controles , Feminino , Humanos , Pessoa de Meia-IdadeRESUMO
Iron deficiency anemia (IDA) is a widespread nutritional disorder that affects a significant proportion of the Brazilian population. The obligatory fortification of wheat flour with iron and folic acid represents a strategy of the Brazilian Ministry of Health for combating IDA. However, several studies have reported the occurrence of iron in excessive concentrations and insufficient contents of folic acid in commercial flour samples. In the light of these information, a participatory observational study on the wheat flour production processes was undertaken in 11 major flour mills located in the São Paulo state, Brazil. This study aimed at writing a detailed good manufacturing practice (GMP) guidelines for the industrial sectors, including directives for standardized operational procedures (SOPs) on the flour fortification. The outcomes of this study are a GMP checklist and the recommended SOPs, which help to standardize the production processes in flour fortification, which currently is incongruous one, and also to facilitate the work of the government health inspectors.(AU)
Anemia por deficiência de ferro (ADF) é um distúrbio nutricional generalizado que afeta uma parcela significativa da população brasileira. A fortificação obrigatória das farinhas de trigo com ferro e ácido fólico representa uma estratégia do Ministério da Saúde para o combate à ADF. No entanto, há relatos que indicam a ocorrência de concentrações excessivas de ferro e quantidades insuficientes de ácido fólico em amostras comerciais de farinha de trigo. À luz destas informações, foi realizado este estudo observacional participativo nos processos de produção de farinha de trigo em 11 moinhos, localizados no estado de São Paulo, Brasil, para criar para este setor industrial, uma lista de verificação das Boas Práticas de Fabricação (BPF), incluindo-se diretrizes para os procedimentos operacionais padronizados (POPs) na fortificação de farinha. A implementação dessas ferramentas ajudam a padronizar os processos de produção, atualmente incongruentes na fortificação das farinhas, bem como facilitam o trabalho dos inspectores de saúde do governo.(AU)
Assuntos
Boas Práticas de Fabricação , Indústria de Farinhas , Triticum , Alimentos Fortificados , Deficiências de Ferro/prevenção & controleRESUMO
Iron deficiency anemia (IDA) is a widespread nutritional disorder that affects a significant proportion of the Brazilian population. The obligatory fortification of wheat flour with iron and folic acid represents a strategy of the Brazilian Ministry of Health for combating IDA. However, several studies have reported the occurrence of iron in excessive concentrations and insufficient contents of folic acid in commercial flour samples. In the light of these information, a participatory observational study on the wheat flour production processes was undertaken in 11 major flour mills located in the São Paulo state, Brazil. This study aimed at writing a detailed good manufacturing practice (GMP) guidelines for the industrial sectors, including directives for standardized operational procedures (SOPs) on the flour fortification. The outcomes of this study are a GMP checklist and the recommended SOPs, which help to standardize the production processes in flour fortification, which currently is incongruous one, and also to facilitate the work of the government health inspectors...
Assuntos
Humanos , Alimentos Fortificados , Boas Práticas de Fabricação , Padrão de Identidade e Qualidade para Produtos e Serviços , Triticum , Deficiências de FerroRESUMO
The aim of this study was to test the hypothesis that magnesium supplementation influences the physical performance of volleyball players, as the efficacy of this approach remains questionable. Twenty-five professional male volleyball players were assigned randomly to experimental (350 mg Mg · d(-1), 4 weeks) and control groups (500 mg maltodextrin · d(-1), 4 weeks) maintaining inter-group homogeneity of urinary magnesium. Erythrocyte, plasma and urinary magnesium levels, plasma creatine kinase activity, lactate production, maximal oxygen uptake (VO2 max) and plyometric (squat jump, countermovement jump, countermovement jump with arm swing) and isokinetic (peak torque, potency and total work) performances were evaluated before (T0) and after (T1) supplementation. Levels of erythrocyte and urinary magnesium and creatine kinase activity and VO2 max remained within normal ranges in both groups. Plasma magnesium decreased significantly only within the experimental group. Significant decreases in lactate production and significant increases (of up to 3 cm) in countermovement jump and countermovement jump with arm swing values were detected in the experimental group following magnesium supplementation, but not in the control group at T1. It is concluded that magnesium supplementation improved alactic anaerobic metabolism, even though the players were not magnesium-deficient.
Assuntos
Desempenho Atlético/fisiologia , Suplementos Nutricionais , Magnésio/administração & dosagem , Voleibol/fisiologia , Adolescente , Adulto , Creatina Quinase/sangue , Método Duplo-Cego , Metabolismo Energético , Humanos , Joelho/fisiologia , Ácido Láctico/sangue , Magnésio/sangue , Magnésio/urina , Masculino , Força Muscular , Consumo de Oxigênio , Resistência Física/fisiologia , Exercício Pliométrico , Adulto JovemRESUMO
Neste estudo foi validada a metodologia de análise de magnésio urinário, plasmático e eritrocitário por espectrofotometria de absorção atômica com chama. As análises foram realizadas em pools de amostras de urina, de plasma e de eritrócitos de humanos. Para a validação, foram considerados os parâmetros de linearidade da curva-padrão, faixa de trabalho, limite de detecção (LD), limite de quantificação (LQ), precisão e exatidão da medição. Os LD e LQ da curva foram, respectivamente, de 0,006 e 0,021 μg/mLde Mg para urina e plasma, e de 0,003 e 0,010 μg/mL de Mg para eritrócitos. A faixa linear de trabalho para determinação de Mg foi entre 0,05 e 0,5 μg/mL de Mg, e as curvas-padrão apresentaram coeficientes de correlação maiores do que 0,99, que demonstram a linearidade da metodologia. As precisões intra e interensaio superiores a 90 por cento foram consideradas adequadas. As recuperações obtidas, usando-se materiais de referência certificados, foram de 101 por cento e de 97 por cento, respectivamente, em urina e plasma. As médias de recuperação por adição de padrão foram de 87 por cento para urina e eritrócitos e de 91 por cento para plasma. A metodologia avaliada foi linear, sensível, seletiva, precisa e exata; portanto, são confiáveis os resultados obtidos.
Assuntos
Humanos , Masculino , Feminino , Eritrócitos , Espectrofotometria Atômica , Fluxo Plasmático Renal , Magnésio , UrinaRESUMO
Deficiencies in calcium (Ca) and magnesium (Mg) are associated with various complications during pregnancy. To test the hypothesis that the status of these minerals is inadequate in pregnancy, a cross-sectional study was conducted of the dietary intake and status of Ca and Mg in pregnant women (n = 50) attending a general public university hospital in Brazil. Dietary intake was assessed from 4-day food records; levels of plasma Mg, erythrocyte Mg, and urinary Ca and Mg excretion were determined by flame atomic absorption spectroscopy; and type I collagen C-telopeptides were evaluated by enzyme-linked immunosorbent assay. Probabilities of inadequate Ca and Mg intake were exhibited by 58 and 98% of the study population, respectively. The mean levels of urinary Ca and Mg excretion were 8.55 and 3.77 mmol/L, respectively. Plasma C-telopeptides, plasma Mg, and erythrocyte Mg were within normal levels. Multiple linear regression analysis revealed positive relationships among urinary Ca excretion, Ca intake (P = .002) and urinary Mg excretion (P < .001) and between erythrocyte Mg and Mg intake (P = .023). It is concluded that the Ca and Mg status of participants was adequate even though the intake of Ca and Mg was lower than the recommended level.
Assuntos
Cálcio/sangue , Deficiência de Magnésio/fisiopatologia , Magnésio/sangue , Desnutrição/fisiopatologia , Complicações na Gravidez/fisiopatologia , Adulto , Brasil/epidemiologia , Cálcio/deficiência , Cálcio/urina , Colágeno Tipo I/sangue , Estudos Transversais , Ingestão de Energia , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Modelos Lineares , Magnésio/urina , Deficiência de Magnésio/epidemiologia , Desnutrição/complicações , Desnutrição/epidemiologia , Estado Nutricional , Peptídeos/sangue , Gravidez , Complicações na Gravidez/epidemiologia , Adulto JovemRESUMO
Neste estudo foi validada a metodologia de análise de magnésio urinário, plasmático e eritrocitário por espectrofotometria de absorção atômica com chama. As análises foram realizadas em pools de amostras de urina, de plasma e de eritrócitos de humanos. Para a validação, foram considerados os parâmetros de linearidade da curva-padrão, faixa de trabalho, limite de detecção (LD), limite de quantificação (LQ), precisão e exatidão da medição. Os LD e LQ da curva foram, respectivamente, de 0,006 e 0,021 μg/mL de Mg para urina e plasma, e de 0,003 e 0,010 μg/mL de Mg para eritrócitos. A faixa linear de trabalho para determinação de Mg foi entre 0,05 e 0,5 μg/mL de Mg, e as curvas-padrão apresentaram coeficientes de correlação maiores do que 0,99, que demonstram a linearidade da metodologia. As precisões intra e interensaio superiores a 90% foram consideradas adequadas. As recuperações obtidas, usando-se materiais de referência certificados, foram de 101% e de 97%, respectivamente, em urina e plasma. As médias de recuperação por adição de padrão foram de 87% para urina e eritrócitos e de 91% para plasma. A metodologia avaliada foi linear, sensível, seletiva, precisa e exata; portanto, são confiáveis os resultados obtidos.(AU)
This study aimed at validating the methodology for analyzing magnesium contents in urine, plasma, and erythrocytes samples by atomic absorption spectrophotometry. Pools of human urine, plasma, and erythrocytes samples were analyzed. The standard curve linearity, linear response range, detection limit (DL), quantitation limit (QL), precision, and accuracy of measurement were determined. DL and QL values were, respectively, 0.006 and 0.021 μg/mL of Mg for urine and plasma, and 0.003 and 0.010 μg/mL of Mg for erythrocytes. The linear response ranged from 0.05 to 0.5 μg/mL of Mg, and the standards curves showed the correlation coefficients higher than 0.99, which demonstrated the linearity of the methodology. Intra- and inter-assay precisions above 90% were considered adequate. The accuracy obtained with certified reference materials for urine and plasma was 101% and 97%, respectively. The average recoveries found by adding the standard were 87% for urine and erythrocytes, and 91% for plasma. Therefore, the evaluated methodology showed to be linear, sensitive, specific, precise and accurate, and the obtained results were reliable.(AU)
Assuntos
Humanos , Animais , Magnésio/análise , Urina/fisiologia , EspectrofotometriaRESUMO
OBJECTIVE: To compare prevalence of anemia and hemoglobin (Hb) levels in Brazilian pregnant women before and after flour fortification with iron. METHODS: A repeated cross-sectional panel study of public health care centers of municipalities in the five Brazilian regions was conducted. Retrospective data were obtained from 12,119 medical records of pregnant women distributed in two groups: before fortification (delivery prior to June 2004) and after fortification (date of last period after June 2005). Anemia was defined as Hb<11.0 g/dl. Hb levels according to gestational age were assessed using two references from the literature. Statistical analysis was carried out using chi-squared tests, Student's t tests, and logistic regression, with a significance level of 5%. RESULTS: In the total sample, prevalence of anemia fell from 25% to 20% after fortification (p<0.001). However, important regional differences were evident: while significant reductions were seen in the Northeast (37% to 29%) and North (32% to 25%) regions, where pre-fortification prevalence was high, smaller reductions were seen in the Southeast (18% to 15%) and South (7% to 6%) regions, where prevalence was low. Hb levels according to gestational age were slightly higher in the first months of pregnancy and lower after the third or fourth months, depending on the reference used. Logistic regression analysis showed that group, geographic region, marital status, trimester of pregnancy, initial nutritional status, and prior pregnancy were associated with anemia (p<0.05). CONCLUSIONS: Prevalence of anemia decreased after fortification, but remains high in the North and Northeast regions. Although fortification may have played a role in this favorable outcome, the contribution of other public policies implemented during the studied period should also be considered.