Patrícia Helen de Carvalho Rondó

Parameters for the assessment of iron status.

The assessment of iron status at individual and populational levels has been the target of many studies because some issues still need to be defined. A Medline, Lilacs and Dedalus literature review was carried out for the period of 1972 to 1998 and scientific publications in both English and Portuguese relating hematological and biochemical parameters were used in the assessment of iron status. The parameters reflect the three different stages of iron storage deficiency, which occur in a gradual and progressive way leading to the development of anaemia. In general, when used alone, these parameters are neither sensitive nor specific for detecting iron deficiency anaemia. Moreover, some advantages and limitations should be taken into consideration for the choice of the appropriate parameter. To improve both sensitivity and specificity, different parameters have been used in association and their specific contribution is determined according to the characteristics of the study population, methodological issues and the costs involved in the process.

The effects of lipoic acid and α-tocopherol supplementation on the lipid profile and insulin sensitivity of patients with type 2 diabetes mellitus: A randomized, double-blind, placebo-controlled trial

Antioxidants probably play an important role in the etiology of type 2 diabetes (DM2). This study evaluated the effects of supplementation with lipoic acid (LA) and α-tocopherol on the lipid profile and insulin sensitivity of DM2 patients. A randomized, double-blind, placebo-controlled trial involving 102 DM2 patients divided into four groups to receive daily supplementation for 4 months with: 600 mg LA (n = 26); 800 mg α-tocopherol (n = 25); 800 mg α-tocopherol + 600 mg LA (n = 25); placebo (n = 26). Plasma α-tocopherol, lipid profile, glucose, insulin, and the HOMA index were determined before and after supplementation. Differences within and between groups were compared by ANOVA using Bonferroni correction. Students t-test was used to compare means of two independent variables. The vitamin E/total cholesterol ratio improved significantly in patients supplemented with vitamin E+LA and vitamin E alone (p ≤ 0.001). There were improvements of the lipid fractions in the groups receiving LA and vitamin E alone or in combination, and on the HOMA index in the LA group, but not significant. The results suggest that LA and vitamin E supplementation alone or in combination did not affect the lipid profile or insulin sensitivity of DM2 patients.

Lipid profile of HIV-infected patients in relation to antiretroviral therapy: a review

This study reviewed the lipid profile of human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) patients in relation to use of antiretroviral therapy (ART), and its different classes of drugs. A total of 190 articles published in peer-reviewed journals were retrieved from PubMed and LILACS databases; 88 of them met the selection criteria and were included in the review. Patients with HIV/AIDS without ART presented an increase of triglycerides and decreases of total cholesterol, low density lipoprotein (LDL-c), and high density lipoprotein (HDL-c) levels. Distinct ART regimens appear to promote different alterations in lipid metabolism. Protease inhibitors, particularly indinavir and lopinavir, were commonly associated with hypercholesterolemia, high LDL-c, low HDL-c, and hypertriglyceridemia. The protease inhibitor atazanavir is apparently associated with a more advantageous lipid profile. Some nucleoside reverse-transcriptase inhibitors (didanosine, stavudine, and zidovudine) induced lipoatrophy and hypertriglyceridemia, whereas abacavir increased the risk of cardiovascular diseases even in the absence of apparent lipid disorders, and tenofovir resulted in lower levels of cholesterol and triglycerides. Although non-nucleoside reverse-transcriptase inhibitors predisposed to hypertriglyceridemia and hypercholesterolemia, nevirapine was particularly associated with high HDL-c levels, a protective factor against cardiovascular diseases. Therefore, the infection itself, different classes of drugs, and some drugs from the same class of ART appear to exert distinct alterations in lipid metabolism.

Relationship between the iron status of pregnant women and their newborns

OBJECTIVE To determine the relationship between iron nutritional status of pregnant women and their newborns using a combination of hematological and biochemical parameters for the diagnosis of iron deficiency. METHODS A cross-sectional study was conducted in Jundiaí, Southeastern Brazil, in 2000. Venous blood samples collected from 95 pregnant women and from their umbilical cord and used for the determination of complete blood count, serum iron, total iron-binding capacity, serum ferritin, zinc protoporphyrin, and transferrin saturation. Women were classified into three groups: anemic, iron deficient and non-iron deficient. Statistical analysis included the Tukey-HSD test, Pearsons correlation coefficient and multiple linear regression analysis. RESULTS Among pregnant women, 19% were anemic (97.9% mildly anemic and 2.1% moderately anemic) and 30.5% were iron deficient. No significant difference was seen in mean values of any parameter studied between newborns in the three groups (p>0.05). Multiple linear regression analysis showed weak association between neonatal and maternal parameters. CONCLUSIONS The iron nutritional status of pregnant women with iron deficiency or mild anemia does not seem to have a significant impact on the iron levels of their children.

Prevalência de deficiência de vitamina A e fatores associados em pré-escolares de Teresina, Piauí, Brasil

A deficiencia de vitamina A constitui um problema de saude publica no Nordeste brasileiro. O objetivo deste estudo foi determinar a prevalencia da deficiencia de vitamina A e os fatores associados em pre-escolares de Teresina, Piaui, Brasil. Os niveis de retinol serico foram determinados por HPLC, e foram investigadas as caracteristicas socio-economicas e demograficas de 631 criancas com idade de 36 a 83 meses. Investigou-se a associacao entre os niveis de retinol e as variaveis de interesse por analise de regressao linear uni e multivariada. O nivel medio de retinol foi de 1,21mmol/L (IC95%: 1,17-1,25µmol/L), independente do sexo (p = 0,259). A hipovitaminose A (retinol < 0,69µmol/L) foi observada em 15,4% das criancas (IC95%: 12,7-18,4), com tendencia a diminuicao com o avanco da idade; 29% das criancas (IC95%: 25,2-32,4) tinham valores aceitaveis de retinol, mas nao adequados (0,70 a 1,04µmol/L). Encontrou-se associacao positiva entre niveis de retinol e idade, renda per capita, suplementacao previa com vitamina A e escolaridade materna. A prevalencia de hipovitaminose A representa um problema moderado de saude publica, ressaltando a importância das estrategias de combate a essa carencia na regiao.

Birth weight, rapid weight gain in infancy and markers of overweight and obesity in childhood

Objective:To evaluate the relationship between birth weight and rapid weight gain in infancy and markers of overweight/obesity in childhood, using different cutoff values for rapid weight gain.Subjects/methods:Cross-sectional study involving 98 5-year old pre-school Brazilian children. Rapid weight gain was considered as weight gain in standard deviation score (SDS) above +0.67, +1 and +2 in relation to birth weight, at any time during the first 2 years of life. The nutritional status of the children was determined by anthropometry and electrical bioimpedance. Multiple linear regression analysis was used, considering fat mass percentage, body mass index (BMI), waist and neck circumferences as outcomes.Results:Birth weight, rapid weight gain (assessed by different cutoff values) and maternal obesity were positively associated with increased fat mass percentage, BMI, waist and neck circumferences. Different cutoff values of rapid weight gain did not change the positive associations between rapid weight gain and fat mass percentage (>+0.67 SDS, P=0.007; >+1 SDS, P=0.007; >+2 SDS, P=0.01), BMI (>+0.67 SDS, P=0.002; >+1 SDS, P=0.007; >+2 SDS, P<0.001), waist circumference (>+0.67 SDS, P=0.002; >+1 SDS, P=0.002; >+2 SDS, P<0.001) and neck circumference (>+0.67 SDS, P=0.01; >+1 SDS, P=0.03; >+2 SDS, P<0.001).Conclusions:The use of different cutoff values for the definition of rapid weight gain did not interfere in the associations between birth weight and rapid weight gain with fat mass percentage, BMI, waist and neck circumferences. Children with the highest birth weight, those who undergo rapid weight gain in infancy and whose mothers were obese, seemed to be more at risk for overweight/obesity.

O papel das selenoproteínas no câncer

Evidence has shown that metabolic disorders are common in tumor cells, leading to increased oxidative stress. The increase in the production of reactive oxygen species (ROS) associated with low antioxidant activity has been related to several types of cancer. Selenium, an antioxidant micronutrient, may function as an antimutagenic agent, preventing the malignant transformation of normal cells. A review of the literature was conducted based on a survey of articles published between 2000 and 2009 in the PubMed database; 39 articles that analyzed the relationship between cancer, oxidative stress and selenium supplementation were selected. The protective effect of this mineral is especially associated with its presence in the glutathione peroxidase and thioredoxin reductase, enzymes that are known to protect DNA and other cellular components against oxidative damage caused by ROS. Several studies have shown reduced expression of these enzymes in various types of cancer, especially when associated with low intake of selenium, which may increase the damage. Selenium supplementation appears to reduce the risk of some types of cancer by reducing oxidative stress and DNA damage. However, further studies are needed to clarify the adequate dose of selenium for each situation (sex, geographic location, and type of cancer).

The influence of maternal factors on the concentration of vitamin A in mature breast milk

BACKGROUND & AIMS This study evaluated the relationship between vitamin A concentration in maternal milk and the characteristics of the donors of a Brazilian human milk bank. MATERIAL AND METHODS A total of 136 donors were selected in 2003-2004 for micronutrient determinations in breast milk and blood, anthropometric measurements and investigation of obstetric, socioeconomic-demographic factors, and life style. Maternal serum/milk samples were obtained for vitamin A, iron, copper, and zinc determinations. Vitamin A concentrations in breast milk and blood were assessed by high-performance liquid chromatography. Copper, zinc and iron concentrations in breast milk, and copper and zinc concentrations in blood were detected by atomic emission spectrophotometry. Serum ceruloplasmin and serum iron were determined, respectively, by nephelometry and colorimetry. A linear regression model assessed the associations between milk concentrations of vitamin A and maternal factors. RESULTS Vitamin A in milk presented positive associations with iron in milk (p<0.001), serum retinol (p=0.03), maternal work (p=0.02), maternal age (p=0.02), and oral contraceptive use (p=0.01), and a negative association with % body fat (p=0.01) (R(2)=0.47). CONCLUSION These results suggest that some nutritional, obstetric, and socioeconomic-demographic factors may have an effect on mature breast milk concentrations of vitamin A in apparently healthy Brazilian mothers.

The relationship between birth weight and insulin resistance in childhood

Chronic diseases that are typical of adulthood may originate in intra-uterine life through inadequate fetal development. The present epidemiological cohort study of 506 healthy children aged 5-8 years evaluated the relationship between birth weight and insulin resistance in an age group that has been assessed in few similar studies. Insulin concentration was determined by chemiluminescence and insulin resistance by the homeostasis model assessment (HOMA). Blood glucose, total cholesterol and fractions (LDL cholesterol and HDL cholesterol) and TAG concentrations were determined by automated enzymatic methods. Linear regression analysis investigated the relationship between birth weight (assessed as a continuous variable and in three categories: small for gestational age, SGA; adequate for gestational age and large for gestational age) and the HOMA index, using backward stepwise selection and biological models to explain the causal pathway of the relationship. There were negative associations between birth weight (P < 0.001), SGA (P = 0.027) and the HOMA index, and a positive association between waist circumference (P < 0.001) and the HOMA index. Considering the significant associations between birth weight and waist circumference (P < 0.001) and waist circumference and insulin resistance (P < 0.001), we can probably suspect that lower birth weight is a common cause of higher waist circumference and insulin resistance. In summary, the results of the present study showed increased insulin resistance in apparently healthy, young children, who had lower weight at birth and higher measurements of waist circumference. There is a need to develop public health policies that adopt preventive measures to promote adequate maternal-fetal and child development and enable early diagnosis of metabolic abnormalities.

Comparison between the HemoCue® and an automated counter for measuring hemoglobin

To determine the precision and agreement of the hemoglobin (Hb) measurements in capillary and venous blood samples by the HemoCue and an automated counter. Hb was determined by both equipments in blood samples of 29 pregnant women. The HemoCue showed low repeatability of Hb measurements in duplicate in capillary (CR=0.53 g/dL, CV=13.6%) and venous blood (CR=0.53 g/dL, CV=13.6%). Hb measurements in capillary blood were higher than those in venous blood (12.4 and 11.7 g/dL, respectively; p<0.05). There was high agreement between Hb in capillary blood by the HemoCue and in venous blood by the counter (r icc=0.86; p<0.01), and also between the diagnosis of anemia by both equipments (k=0.81; p<0.01). The HemoCue seems to be more appropriate for capillary blood and require training of the measurers.