Leptin receptor expression in blood mononuclear cells of lactating women is associated with infant body weight: Potential role as a molecular biomarker

BACKGROUND

Molecular biomarkers of maternal leptin resistance associated with infant weight are needed.

OBJECTIVES

To evaluate gene expression of leptin receptor (LEPR), suppressor of cytokine signalling 3 (SOCS3) and insulin receptor in peripheral blood mononuclear cells (PBMCs) of lactating women and their relationship with infant body weight and adiposity.

METHODS

At day 10 postpartum, maternal gene expression in PBMCs as well as leptin and insulin concentrations in plasma and milk were assessed (n = 68). Infant weight and BMI z-scores, skinfolds and arm circumference were obtained at 10 days and/or at 3 months old.

RESULTS

In mothers with pre-pregnancy overweight or obesity (OW/OB), LEPR expression was reduced (p = 0.013) whereas plasma and milk leptin and milk insulin concentrations were elevated. LEPR expression was positively related with infant weight z-score (Beta (95% CI): 0.40 (0.17, 0.63), p = 0.001) but not with leptin concentrations. SOCS3 expression was positively related with infant weight z-score (Beta (95% CI): 0.28 (0.04, 0.51), p = 0.024) and arm circumference (Beta (95% CI): 0.57 (0.32, 0.82), p < 0.001). Relationships remained significant after adjusting for maternal and infant confounders.

CONCLUSIONS

LEPR and SOCS3 gene expression in PBMCs are novel maternal molecular biomarkers that reflect leptin resistance and are associated with infant body weight and adiposity.

Effectiveness of weekly and daily iron administration for the prevention of iron deficiency anemia in infants

Introduction. Iron deficiency (ID) is the most prevalent nutritional deficiency and the main cause of anemia in infants. There is consensus on daily iron supplementation as a preventive strategy; and weekly iron supplementation has also been shown to be effective, but evidence in infants is scarce. The objective of this study was to compare the effectiveness of daily versus weekly iron administration for the prevention of ID anemia (IDA) in infants. Population and methods. Randomized, controlled clinical trial. Infants seen at a public health center, without anemia at 3 months of age, were randomized into 3 groups: daily supplementation (1 mg/kg/day), weekly supplementation (4 mg/kg/week), or no supplementation (control group with exclusive breastfeeding [EB]). Anemia and ID were assessed at 3 and 6 months old. Adherence and adverse events were recorded. Data were analyzed using the R software, version 4.0.3. Results. A total of 227 infants participated. At 6 months, the group of infants with EB without supplementation (control) had a higher prevalence of ID and IDA than the intervention groups (daily and weekly). ID: 40.5% versus 13.5% and 16.7% (p = 0.002); IDA: 33.3% versus 7.8% and 10% (p < 0.001). There were no differences between the daily and weekly supplementation groups. There were also no differences in the percentage of high adherence to supplementation (50.6% daily versus 57.1% weekly) or adverse events. Conclusions. No significant differences in effectiveness were observed between daily and weekly administration for the prevention of infant IDA.

Environmental exposure to lead and oxidative stress biomarkers among healthy children in La Plata, Argentina

INTRODUCTION

Environmental exposure to lead is still a major public health problem, especially in children. Oxidative stress may be a primary mechanism associated with toxicity. The objective of this study was to measure blood lead levels (BLLs) in children aged 1 to 6 years exposed to lead in La Plata and suburban areas and their relation to oxidative stress biomarkers.

POPULATION AND METHODS

Cross-sectional, analytical study. Clinically healthy children aged 1 to 6 years were analyzed. BLLs, antioxidant enzyme activity, and extent of lipid peroxidation were measured. The statistical software package R, version 3.5.1, was used.

RESULTS

A total of 131 children participated; their median age was 2.33 years. The geometric mean of BLLs was 1.90 μg/dL; 32% showed a measurable BLL and 3%, BLLs ≥ 5 μg/dL (international reference). The comparison of oxidative stress biomarkers based on BLLs showed a significant difference in median thiobarbituric acid reactive substances (TBARS): 12.0 versus 10.0 nmol MDA/mL of plasma; p = 0.02. In addition, the correlation between BLLs and TBARS was positive (r = 0.24; p = 0.012).

CONCLUSIONS

Most children had a BLL below the limit recommended by international agencies; although such BLLs do not affect antioxidant enzyme activity, they can induce lipid peroxidation. These results demonstrate the usefulness of this biomarker as an early diagnosis tool to assess subtoxic lead effects.

Contribution of enriched wheat flour and flour products to iron requirements in children aged 6 months to 7 years

INTRODUCTION

Wheat flour enrichment is a public health strategy recommended to prevent micronutrient deficiencies, including iron deficiency. The objective of this study was to determine iron content in enriched wheat flour and flour products and their contribution to nutritional recommendations for children.

POPULATION AND METHODS

Observational, analytical, cross-sectional study based on the total diet study method. Enriched wheat flour (as per Law no. 25630) and the most frequently consumed flour products were analyzed. Products were selected using a questionnaire on the frequency of food intake and a 24-hour recall interview with the parents of children aged 6 months to 7 years. Food iron levels were determined based on atomic absorption spectrometry and their contribution to the estimated average requirement was assessed.

RESULTS

Enriched flour and flour products showed the expected iron amount, except for French bread and breadcrumbs. The contribution of studied products to iron requirements was 7 % in children aged 6 months to 1 year, 81 % in those aged 1-3 years, and 45 % in those older than 4 years.

CONCLUSIONS

Except for French bread and breadcrumbs, studied flour and flour products showed the expected enrichment level. The consumption of this type of food does not provide significant amounts of iron to infants, but it does to children older than 1 year.

Multitemporal optical and radar metrics for wetland mapping at national level in Albania

Wetlands are highly dynamic, with many natural and anthropogenic drivers causing seasonal, periodic or permanent changes in their structure and composition. Thus, it is necessary to use time series of images for accurate classifications and monitoring. We used all available Sentinel-1 and Sentinel-2 images to produce a national wetlands map for Albania. We derived different indices and temporal metrics and investigated their impacts and synergies in terms of mapping accuracy. Best results were achieved when combining Sentinel-1 with Sentinel-2 and its derived indices. We reduced systematic errors and increased the thematic resolution using morphometric characteristics and knowledge-based rules, achieving an overall accuracy of 82%. Results were also validated against field inventories. This methodology can be reproducible to other countries and can be made operational for an integrated planning that considers the food, water, and energy nexus.

Vitamin A deficiency and associated factors in preschoolers from the outskirts of La Plata, Buenos Aires

INTRODUCTION

Vitamin A deficiency (VAD) has been recognized as an important public health problem in developing countries. Preschoolers account for risk groups within vulnerable populations. The objective of this study was to determine the prevalence of VAD and associated factors in a sample of preschoolers.

MATERIALS AND METHODS

Cross-sectional study with children aged 1-6 years receiving social assistance and seen at primary health care centers in the outskirts of the city of La Plata, Buenos Aires. Vitamin A levels were determined by measuring serum retinol with a liquid chromatography; anthropometric parameters and dietary intake were recorded. A multinomial logistic regression model was used to assess the association among outcome measures.

RESULTS

Data from 624 children were analyzed. The geometric mean of retinol was 23.8 pg/dL (95 % CI: 23.3-24.3). The prevalence of VAD and the risk for VAD were 24.3 % and 57.4 %, respectively. Retinol levels were significantly lower among boys, low-weight children, and those with low intake (below the first tertile of distribution). The multivariate analysis showed a significant association between VAD and male sex (odds ratio: 1.93; 95 % CI: 1.15-3.24) and between VAD and low intake (odds ratio: 1.48; 95 % CI: 1.15-2.62).

CONCLUSION

The prevalence of VAD (24.3 %) is a major public health problem in this population. VAD-associated factors were male sex and low vitamin A intake.

Nocturnal but not Diurnal Hypertension Is Associated to Insulin Resistance Markers in Subjects With Normal or Mildly Elevated Office Blood Pressure

OBJECTIVE

The aim was to evaluate the relationships among insulin resistance markers and nocturnal and diurnal hypertension in normotensive or mildly untreated hypertensive adults.

METHODS

The study was performed in both female and male adults referred to the Cardiometabolic Unit of the Hospital San Martín, La Plata, Argentina, in order to perform an ambulatory blood pressure measurement (ABPM) for the evaluation of a possible hypertensive disorder. The population was stratified according to their ABPM in: 1-presence or absence of diurnal hypertension and 2-presence or absence of nocturnal hypertension; both conditions were analyzed separately. Fasting plasma insulin (FPI), homeostasis model assessment of insulin resistance (HOMA-IR), and triglycerides (TG)/high-density lipoprotein cholesterol (HDL-C) ratio were used as surrogate markers of insulin resistance and compared among subjects with vs. without diurnal or nocturnal hypertension.

RESULTS

One hundred and five patients, 55 women, 47 (11) years old, and 50 men, 44 (16) years old, were included. Diurnal and nocturnal hypertension were found in 60% and 64% of the sample, respectively. There were no significant differences among the levels of insulin resistance markers between individuals with or without diurnal hypertension. In contrast, individuals with nocturnal hypertension were more insulin resistant irrespectively of whether they were evaluated using FPI (P = 0.016), HOMA-IR (P = 0.019), or TG/HDL-C ratio (P = 0.011); FPI differences remained significant after adjustment for sex, age, and obesity indicators (P = 0.032).

CONCLUSIONS

Nocturnal but not diurnal hypertension was related to higher levels of 3 insulin resistance markers in normotensive and untreated mildly hypertensive adults; this relationship seems partially independent of obesity.

Blood lead levels in children aged between 1 and 6 years old in La Plata, Argentina. Identification of risk factors for lead exposure

INTRODUCTION

Lead has neurotoxic effects in children, even at a very low level in blood. The risk factors (RFs) for lead exposure have not been adequately identified in La Plata. The objectives of this study were to determine mean blood lead levels and identify RFs in children aged 1 to 6 years old living in La Plata and the outskirts.

POPULATION AND METHODS

A cross-sectional study was conducted in children who attended primary health care centers for a health check-up. Blood lead levels were determined by atomic absorption spectroscopy, and a socioenvironmental survey was administered to outline RFs. The Mann-Whitney test was used to compare measurements. A multivariate statistical analysis was done to establish the most relevant RFs.

RESULTS

A total of 319 children participated (51% were boys); the median (interquartile range) blood lead level was 2.2 pg/dL (1.1-3.6 pg/dL). Significant mean differences in blood lead levels were observed for age≤ 3years old, anemia, pica behavior, overcrowding, dirt floors, and maternal education < 7 years. Age≤ 3years old and pica behavior were both RFs with significant odds ratios (ORs). The OR as adjusted by logistic regression was significant only for age≤ 3years old.

CONCLUSIONS

The median blood lead level in the studied population was 2.2 pg/dL. The main RFs identified for lead exposure were age≤ 3years old and pica behavior. Other less relevant RFs included anemia, maternal education < 7 years, overcrowding, and dirt floors.

Blood lead levels in children aged between 1 and 6 years old in La Plata, Argentina. Identification of risk factors for lead exposure

INTRODUCTION

Lead has neurotoxic effects in children, even at a very low level in blood. The risk factors (RFs) for lead exposure have not been adequately identified in La Plata. The objectives of this study were to determine mean blood lead levels and identify RFs in children aged 1 to 6 years old living in La Plata and the outskirts.

POPULATION AND METHODS

A cross-sectional study was conducted in children who attended primary health care centers for a health check-up. Blood lead levels were determined by atomic absorption spectroscopy, and a socioenvironmental survey was administered to outline RFs. The Mann-Whitney test was used to compare measurements. A multivariate statistical analysis was done to establish the most relevant RFs.

RESULTS

A total of 319 children participated (51% were boys); the median (interquartile range) blood lead level was 2.2 pg/dL (1.1-3.6 pg/dL). Significant mean differences in blood lead levels were observed for age≤ 3years old, anemia, pica behavior, overcrowding, dirt floors, and maternal education < 7 years. Age≤ 3years old and pica behavior were both RFs with significant odds ratios (ORs). The OR as adjusted by logistic regression was significant only for age≤ 3years old.

CONCLUSIONS

The median blood lead level in the studied population was 2.2 pg/dL. The main RFs identified for lead exposure were age≤ 3years old and pica behavior. Other less relevant RFs included anemia, maternal education < 7 years, overcrowding, and dirt floors.

Localized self-heating in large arrays of 1D nanostructures

One dimensional (1D) nanostructures offer a promising path towards highly efficient heating and temperature control in integrated microsystems. The so called self-heating effect can be used to modulate the response of solid state gas sensor devices. In this work, efficient self-heating was found to occur at random networks of nanostructured systems with similar power requirements to highly ordered systems (e.g. individual nanowires, where their thermal efficiency was attributed to the small dimensions of the objects). Infrared thermography and Raman spectroscopy were used to map the temperature profiles of films based on random arrangements of carbon nanofibers during self-heating. Both the techniques demonstrate consistently that heating concentrates in small regions, the here-called "hot-spots". On correlating dynamic temperature mapping with electrical measurements, we also observed that these minute hot-spots rule the resistance values observed macroscopically. A physical model of a random network of 1D resistors helped us to explain this observation. The model shows that, for a given random arrangement of 1D nanowires, current spreading through the network ends up defining a set of spots that dominate both the electrical resistance and power dissipation. Such highly localized heating explains the high power savings observed in larger nanostructured systems. This understanding opens a path to design highly efficient self-heating systems, based on random or pseudo-random distributions of 1D nanostructures.

Protein energy-malnutrition: does the in vitro zinc sulfate supplementation improve chromosomal damage repair?

Protein-energy malnutrition (PEM) is originated by a cellular imbalance between nutrient/energy supply and body's demand. Induction of genetic damage by PEM was reported. The purpose of this study was to determine the genetic effect of the in vitro zinc sulfate (ZnSO4) supplementation of cultured peripheral blood lymphocytes from children with PEM. Twenty-four samples from 12 children were analyzed. Anthropometric and biochemical diagnosis was made. For the anthropometric assessment, height-for-age index, weight-for-age index, and weight-for-height index were calculated (WHO, 2005). Micronutrient status was evaluated. A survey for assessed previous exposure to potentially genotoxic agents was applied. Results were statistically evaluated using paired sample t test and χ (2) test. Each sample was fractionated and cultured in two separate flasks to performed two treatments. One was added with 180 μg/dl of ZnSO4 (PEMs/ZnSO4) and the other remains non-supplemented (PEMs). Cytotoxic effects and chromosomal damage were assessed using the cytokinesis-block micronucleus assay (CBMN). All participants have at least one type of malnutrition and none have anemia, nor iron, folate, vitamin A, and zinc deficiency. All PEMs/ZnSO4 samples have a significant reduction in the micronucleus (MNi) frequency compared with PEMs (t = 6.25685; p < 0.001). Nuclear division index (NDI) increase in PEMs/ZnSO4 (t = -17.4226; p < 0.001). Nucleoplasmic bridge (NPBs) frequency was four times smaller in PEMs/ZnSO4 (χ (2) = 40.82; p < 0.001). No nuclear buds (NBuds) were observed. Cytotoxic effects and chromosomal damage observed in children suffering from PEM can be repaired in vitro with zinc sulfate supplementation.

Prenatal lead exposure and relationship with maternal exposure determinants in a public maternity hospital of La Plata, Argentina

Prenatal lead exposure is a health hazard that may cause cognitive development impairments and other adverse effects in children. We conducted a cross sectional study analyzing cord blood lead levels (CBLL) of newborns and their relationship with maternal determinants of lead exposure. Mothers answered a questionnaire about socio-demographic, lifestyle habits and environmental characteristics. We used Mann-Whitney's test to compare CBLL geometrical means (GM) corresponding to the presence or absence of each lead exposure determinant, and Chi square test to study the relationship between CBLL and maternal lead exposure determinants. A total of 159 newborns participated in the study. CBLL GM was 2.1 μg/dL; and 25% of the participants had a measurable CBLL (LOQ=3.3 μg/dl). Although the participants had several determinants of lead exposure, we only found a significant relationship with inside household determinants, such as presence of lead piping (p=0.026), unplastered walls (p=0.046) and peeling paint (p=0.048). Our results show that CBLL GM was similar to that reported in several studies conducted around the world. However, 25% of the participants might have some degree of risk for lead poisoning.

Short-term evaluation of the impact of a fortified food aid program on the micronutrient nutritional status of Argentinian pregnant women

We studied the impact of a food supplementation program (Plan Más Vida (PMV)) on the micronutrient nutritional condition of pregnant women from low-income families 1 year after its implementation. The food program provided supplementary diet (wheat and maize--fortified flour, rice or sugar, and fortified soup). We performed a prospective, nonexperimental, cross-sectional study in the province of Buenos Aires, Argentina, evaluating pregnant women at baseline (n = 164) and 1 year after PMV implementation (n = 108). Biochemical tests (hemogram, ferritin, vitamin A, zinc, and folic acid), anthropometric assessments (weight and height), and dietary surveys (24 h recall) were performed at the two study points. One year after PMV implementation, no significant changes in anthropometric values were observed. Folic acid deficiency and the risk of vitamin A deficiency (retinol, 20-30 μg/dl) decreased significantly (35.8 to 6.1 % and 64 to 41 %, respectively; p < 0.000). Anemia and prevalence of iron and zinc deficiency values did not change. Diet survey results showed that although nutrient intake increased significantly, it was still below recommendations. Implementation of the PMV and of the government nutritional strategies had a high impact on the prevalence of folic acid deficiency. We also observed a decrease in the risk of vitamin A deficiency, and no impact on iron and zinc nutritional status. Adherence to the specific fortified food (soup) was not good and intra-family dilution and distribution of food was high.

Evaluation of the impact of a food program on the micronutrient nutritional status of Argentinean lactating mothers

This study was conducted to evaluate the impact of a food aid program (Plan Más Vida, PMV) on the micronutrient nutritional condition of lactating mothers 1 year after its implementation. The food program provided supplementary diets (wheat- and maize-fortified flour, rice or sugar, and fortified soup) to low-income families from the province of Buenos Aires, Argentina. A prospective, non-experimental study was carried out to evaluate the micronutrient nutritional status of lactating mothers (n = 178 at baseline and n = 151 after 1 year). Biochemical tests (hemoglobin, ferritin, zinc, vitamin A, and folic acid), anthropometric assessments (weight and height) and dietary surveys (24-h recall) were performed. We found no significant changes in anthropometric values 1 year after the intervention. The risk for vitamin A (retinol 20-30 μg/dl) and folate deficiency significantly decreased 1 year after PMV implementation (56.3 vs. 29.9 and 50.3 vs. 3.4 %, respectively; p < 0.001). Anemia was seen in 25.8 % of lactating mothers at baseline, without statistically significant differences 1 year after (p = 0.439). The nutritional data obtained after assessing the early impact of PMV actions may be useful to provincial health authorities to perform periodic evaluations in the future.

Short-term evaluation of the impact of a food program on the micronutrient nutritional status of Argentinean children under the age of six

This study was undertaken to evaluate the impact of Plan Más Vida (PMV) on the micronutrient nutritional condition of children aged 1 to 6 years 1 year after PMV implementation. The food program was intended for low-income families from the province of Buenos Aires, Argentina and provided supplementary diets. A prospective, nonexperimental study was carried out. Children (472 at baseline and 474 after 1 year) were divided into two groups (1-2 and 2-6 years of age). Biochemical tests (hemogram, ferritin, zinc, vitamin A, and folic acid), anthropometric assessments (weight and height), and dietary surveys (24-h recall) were performed. Chronic growth retardation (-2 height/age Z-score) was present in 2.8% and 8.7% of 1-2- and 2-6-year-old children, respectively; 14.4% in the former and 8.8% in the latter group had overweight/obesity. No significant changes were recorded 1 year after PMV implementation. Whereas anemia values decreased (55.3% to 39.1%, p = 0.003) and serum zinc values increased in 1-2-year-old children, the risk for vitamin A deficiency decreased significantly in both age groups. The evaluation of the early impact of PMV actions provided important nutritional data that should be used by provincial health authorities to conduct future evaluations.

Effect of probiotic supplementation on immunoglobulins, isoagglutinins and antibody response in children of low socio-economic status

BACKGROUND

Antigen exposure is one of the major exogenous factors modulating human immunocompetence acquisition. Decline in family size and improvements in public health and hygiene in developed countries, may deprive the immune system of appropriate antigen input by diminishing infectious stimuli. Probiotics are a large group of microorganisms defined by their beneficial effects on human health and with stimulating effects on different functions of the immune system.

AIM OF THE STUDY

We conducted a double-blind, placebo-controlled trial to determine if probiotics maintain their immune-stimulating effects in a population of 162 children with a high index of natural exposure to microorganisms. Children were to ingest for at least 4 months one of two products, low-fat milk fermented by Streptococcus thermophilus (control product) or low-fat milk fermented by S. thermophilus and Lactobacillus casei, with Lactobacillus acidophilus, oligofructose and inulin added after the fermentation process (test product). According to their age, children were vaccinated with DTP-Hib vaccine or a 23-valent anti-pneumococcal vaccine.

RESULTS

Final analysis of results was done in 70 children in each group, showing that the rate of immunoglobulin and isoagglutinin acquisition was similar in both groups. There was no difference between groups in antibody levels neither before nor after vaccination. Days of fever and number of episodes of infection were not statistically different in either group.

CONCLUSIONS

Supplementation of standard fermented milk with additional probiotics was not of benefit. The high natural rate of early microbial exposure in infants and children from a population of low socio-economic status living in a "less hygienic environment" may account for the absence of an additional immune-stimulating effect by supplementary probiotics.

[Blood lead levels in children from the city of La Plata, Argentina. Relationship with iron deficiency and lead exposure risk factors]

INTRODUCTION

Environmental exposure to lead and the subsequent poisoning are a main public health concern worldwide. Children have a higher vulnerability to lead toxic effects, and many reports have shown the association between iron deficiency and lead poisoning. In Argentina, reports about lead levels in children are scarce. Our aims were to assess blood lead levels in children and determining their relationship with iron deficiency and known lead exposure risk factors.

MATERIAL AND METHODS

We performed a cross-sectional study in a sample of 93 children (age range, 6 months to 5 years) receiving care at La Plata Children s Hospital. A social and environmental survey was done, and blood lead, hemoglobin and ferritin levels were assessed.

RESULTS

Geometric mean blood lead level was 4.26 microg/dl (95% CI, 3.60-5.03); prevalence of blood lead levels >or=10 microg/dl was 10.8%. Higher blood lead levels were found in children living in households with lead-handling contaminating activities (6.74 vs. 3.78 microg/dl; p= 0.005) and in very low-income households (5.68 vs. 3.71 microg/ dl; p= 0.020). The presence of blood lead levels >or=10 microg/dl was strongly associated with iron deficiency (OR 5.7; 95% CI: 1.34-23.41) and with lead-handling activities at home (OR 4.8; 95% CI: 1.12-20.16).

CONCLUSION

The prevalence of blood lead levels >or=10 microg/dl is a matter of concern in the population studied. Iron deficiency and development of lead-handling activities at home were the risk factors associated with high blood lead levels.