The clinical-epidemiological profile of malaria patients from Southern Venezuela, a critical hotspot in Latin America.

BACKGROUND: Venezuela accounted for 55% of the cases and 73% of the malaria deaths in the Americas in 2019. Bolivar state, in the southeast, contributes > 60% of the country's Plasmodium vivax and Plasmodium falciparum cases every year. This study describes the clinical-epidemiological characteristics of clinical malaria patients in this high-transmission area. METHODS: A prospective study was conducted on patients seeking medical attention in three medical centres in the state capital, Ciudad Bolivar, between June and October 2018. Malaria diagnosis was carried out using microscopy following national standards. Malaria-positive patients were examined for clinical symptoms, and haematological tests were performed at the time of diagnosis. Patients were followed up by telephone to evaluate malaria recurrences. RESULTS: Out of 287 patients, 200 (69.7%) were positive for P. vivax, 69 (24%) for P. falciparum, and 18 (6.3%) had mixed (P. vivax/P. falciparum) infections. Patients' median age was 33 years (IQR 20), 168 (69%) were men, and 40% practiced gold mining as the main occupation. Fever (96.5%), chills (91.3%), and headaches (90.6%) were the most frequent symptoms. At least one symptom associated with severe malaria was observed in 69 out of 161 patients with complete clinical evaluation (42.9%). Plasmodium vivax infections were found in 42 out of 69 (60.9%) severe cases; by contrast, P. falciparum and mixed malaria caused 34.8% (24/69) and 4.4% (3/69) of infections, respectively. Two patients died of cerebral malaria. Mean hemoglobin was lower in the patients infected with P. falciparum than those infected with P. vivax. Regardless of the parasite causing the infection, patients presented high levels of total bilirubin, aminotransferases (AST, ALT), and lactate dehydrogenase (LDH). Out of the 142 patients followed up by phone for three months (49.5% of the 287 patients), 35 (24.7%) reported recurrences. CONCLUSIONS: The high malaria prevalence among young male adults practicing gold mining suggests that this occupation is a significant risk factor. The unexpected high prevalence of P. vivax patients with at least one criteria of severe clinical disease is a matter of concern. Whether it is the result of a lack of timely diagnosis and effective treatment should be explored.

Non-high-density lipoprotein cholesterol curves in Argentinean indigenous children living at high altitude and US children.

OBJECTIVE: To describe the non-high-density lipoprotein cholesterol (non-HDL-C) as mean and percentiles by age and sex in Argentinean indigenous schoolchildren living at 3750 m, contrasting these estimates with those reported in the 2011-2012 National Center for Health Statistics reference population (NHANES). METHODS: Non-HDL-C was calculated as total cholesterol-HDL-C. Analyses incorporated sampling weights for age and sex to obtain unbiased estimates. Sex- and age-specific smoothed percentile curves were performed with Cole's LMS method. RESULTS: A total of 236 (49% males) children from San Antonio de los Cobres (SAC) were evaluated twice and compared with 1409 NHANES children. Non-HDL-C values were 4 mg/dL higher in SAC than in NHANES (109 vs 105 mg/dL, respectively). Trends in non-HDL-C 50th percentile in females differed between ages 6 to 7 and 8 years; in SAC non-HDL-C decreased from 111 to 104 mg/dL, NHANES levels remained stable from103 to 104 mg/dL. Among children aged 9 to10 years, non-HDL-C increased from 114 mg/dL to 117 mg/dL in SAC, but decreased from 113 to 107 mg/dL in NHANES. Between ages 12 and 13 years, non-HDL-C increased from 108 to 120 mg/dL in SAC, and remained steady from105 to 106 mg/dL in NHANES. The 50th percentile of non-HDL-C in males showed similar trends except for ages 6 to 7 to age 8 when non-HDL-C remained stable from 106 to 107 mg/dL in SAC, and increased from 98 mg/dL to 104 mg/dL in NHANES. CONCLUSIONS: Non-HDL-C levels in children vary with age, sex, ethnicity, and altitude. Different patterns in non-HDL-C were observed for girls in SAC compared with NHANES. However, more stable patterns were observed in boys in both groups.

Prevalence and molecular characterization of G6PD deficiency in two Plasmodium vivax endemic areas in Venezuela: predominance of the African A-(202A/376G) variant.

BACKGROUND: Glucose-6-phosphate dehydrogenase (G6PD) deficiency causes acute haemolytic anaemia triggered by oxidative drugs such as primaquine (PQ), used for Plasmodium vivax malaria radical cure. However, in many endemic areas of vivax malaria, patients are treated with PQ without any evaluation of their G6PD status. METHODS: G6PD deficiency and its genetic heterogeneity were evaluated in northeastern and southeastern areas from Venezuela, Cajigal (Sucre state) and Sifontes (Bolívar state) municipalities, respectively. Blood samples from 664 randomly recruited unrelated individuals were screened for G6PD activity by a quantitative method. Mutation analysis for exons 4-8 of G6PD gen was performed on DNA isolated from G6PD-deficient (G6PDd) subjects through PCR-RFLP and direct DNA sequencing. RESULTS: Quantitative biochemical characterization revealed that overall 24 (3.6%) subjects were G6PDd (average G6PD enzyme activity 4.5 ± 1.2 U/g Hb, moderately deficient, class III), while DNA analysis showed one or two mutated alleles in 19 of them (79.2%). The G6PD A-(202A/376G) variant was the only detected in 17 (70.8%) individuals, 13 of them hemizygous males and four heterozygous females. Two males carried only the 376A → G mutation. No other mutation was found in the analysed exons. CONCLUSIONS: The G6PDd prevalence was as low as that one shown by nearby countries. This study contributes to the knowledge of the genetic background of Venezuelan population, especially of those living in malaria-endemic areas. Despite the high degree of genetic mixing described for Venezuelan population, a net predominance of the mild African G6PD A-(202A/376G) variant was observed among G6PDd subjects, suggesting a significant flow of G6PD genes from Africa to Americas, almost certainly introduced through African and/or Spanish immigrants during and after the colonization. The data suggest that 1:27 individuals of the studied population could be G6PDd and therefore at risk of haemolysis under precipitating factors. Information about PQ effect on G6PDd individuals carrying mild variant is limited, but since the regimen of 45 mg weekly dose for prevention of malaria relapse does not seem to be causing clinically significant haemolysis in people having the G6PD A-variant, a reasoned weighing of risk-benefit for its use in Venezuela should be done, when implementing public health strategies of control and elimination.

Healthier Lipid Profiles with Vitamin D Supplementation in a Pilot Study in Argentinean Children of Two Ethnicities.

OBJECTIVE: to explore changes in lipid levels in two groups of children of different ethnicities who were able to access vitamin D supplementation versus those who were not. METHODS: A prospective one-year study evaluated 87 San Antonio de los Cobres (SAC) Indigenous and 36 Buenos Aires (BA) urban schoolchildren aged 9.7 + 2.1 years between October 2013 and October 2014. SAC children included 70 (80.5%) treated with 100,000 IU/year of vitamin D and 17 (19.5%) untreated; and BA children included 25 (69,5%) treated and 11(30.5%) untreated. BMI, lipids, and 25-hydroxyvitamin D (25(OH)D) concentrations were measured at baseline and after one year. RESULTS: There was a significantly lower prevalence of overweight/obesity in SAC (n = 7; 8%) versus BA (n = 7; 36.4%) children. There was a significant association between changes in (25(OH)D) and changes in HDL-C levels in SAC (r0.44;p < 0.01) and in BA (r0.34;p < 0.05). Multiple linear regression analyses showed that changes in (25(OH)D ) were significantly associated with changes in HDL-C in SAC (Beta = 0.55, p = 0.02; R20.11) and BA children (Beta = 0.42, p = 0.04; R2 0.21) adjusted for age, gender, and BMI. Furthermore, multiple logistic regression analysis showed that children in the treated group had a likelihood six times greater of having HDL-C >40 mg/dL than the untreated group, adjusted for age, gender, and BMI (OR 6.3: CI 2.0 - 19.8; p < 0.01). CONCLUSION: These results suggest that children who had received vitamin D supplementation had significantly higher vitamin D status and HDL-C, as compared with non-supplemented children in both communities.

Tuning supramolecular G-quadruplexes with mono- and divalent cations.

Supramolecular G-quadruplexes (SGQs) are formed via the cation promoted self-assembly of guanine derivatives into stacks of planar hydrogen-bonded tetramers. Here, we present results on the formation of SGQs made from the 8-(m-acetylphenyl)-2'-deoxyguanosine (mAGi) derivative in the presence of various mono- and divalent cations. NMR and HR ESI-MS data indicate that varying the cation can efficiently tune the molecularity, the fidelity and stability (thermal and kinetic) of the resulting SGQs. The results show that, parallel to the previously reported potassium-templated hexadecamer (mAGi16·3K+), Na+, Rb+ and [Formula: see text] also promote the formation of similar supramolecules with high fidelity and molecularity. In contrast, the divalent cations Pb2+, Sr2+ and Ba2+ template the formation of octamers (mAGi8), with the latter two inducing higher thermal stabilities. Molecular dynamics simulations for the hexadecamers containing monovalent cations enabled critical insights that help explain the experimental observations.

Humoral Immunity across the SARS-CoV-2 Spike after Sputnik V (Gam-COVID-Vac) Vaccination.

SARS-CoV-2 vaccines have contributed to attenuating the burden of the COVID-19 pandemic by promoting the development of effective immune responses, thus reducing the spread and severity of the pandemic. A clinical trial with the Sputnik-V vaccine was conducted in Venezuela from December 2020 to July 2021. The aim of this study was to explore the antibody reactivity of vaccinated individuals towards different regions of the spike protein (S). Neutralizing antibody (NAb) activity was assessed using a commercial surrogate assay, detecting NAbs against the receptor-binding domain (RBD), and a plaque reduction neutralization test. NAb levels were correlated with the reactivity of the antibodies to the spike regions over time. The presence of Abs against nucleoprotein was also determined to rule out the effect of exposure to the virus during the clinical trial in the serological response. A high serological reactivity was observed to S and specifically to S1 and the RBD. S2, although recognized with lower intensity by vaccinated individuals, was the subunit exhibiting the highest cross-reactivity in prepandemic sera. This study is in agreement with the high efficacy reported for the Sputnik V vaccine and shows that this vaccine is able to induce an immunity lasting for at least 180 days. The dissection of the Ab reactivity to different regions of S allowed us to identify the relevance of epitopes outside the RBD that are able to induce NAbs. This research may contribute to the understanding of vaccine immunity against SARS-CoV-2, which could contribute to the design of future vaccine strategies.

Seroprevalence of viral and bacterial pathogens among malaria patients in an endemic area of southern Venezuela.

BACKGROUND: Malaria remains a leading public health problem worldwide. Co-infections with other pathogens complicate its diagnosis and may modify the disease's clinical course and management. Similarities in malaria clinical presentation with other infections and overlapping endemicity result in underdiagnosis of co-infections and increased mortality. Thus, the aim of this study was to determine the seroprevalence of viral and bacterial pathogens among diagnosed malaria patients in malaria-endemic areas in Venezuela. METHODS: A cross-sectional study was conducted on malaria patients attending three reference medical centres in Ciudad Bolivar, Venezuela. Clinical evaluation and laboratory tests for dengue virus (DENV), chikungunya virus (CHIKV), viral hepatitis [hepatitis A virus (HAV), hepatitis B virus (HBV), and hepatitis C virus (HCV)], and leptospirosis (LEP) were performed by enzyme-linked immunosorbent assays. Previous exposure to these pathogens was defined by the presence of specific immunoglobulin (Ig) G, and co-infection or recent exposure (CoRE) was determined by the presence of specific IgM alone or IgM + IgG. Data analysis considered descriptive statistics. Parameter distribution was statistically evaluated using Kolmogorov-Smirnov test and the necessary comparison tests. Odds ratio (OR) for complications was determined according to CoRE presence with a 95% confidence interval (CI). RESULTS: A total of 161 malaria patients were studied, 66% infected with Plasmodium vivax, 27% with P. falciparum, and 7.5% harboured P. vivax/P. falciparum mixed infection. Previous exposure to DENV (60%) and CHIKV (25%) was frequent. CoRE was confirmed in 55 of the 161 malaria patients (34%) and were more frequent in P. falciparum (49%) than in P. vivax (29%) and mixed malaria patients (25%) (OR = 2.43, 95% CI: 1.39-4.25, P = 0.018). The most frequent CoRE was DENV (15%), followed by HAV (12%), HBV (6.2%), CHIKV (5.5%), and LEP (3.7%); HCV CoRE was absent. Complicated malaria was significantly more frequent in patients with CoRE (56%) than those without CoRE (36%; OR = 2.31, 95% CI: 1.18-4.92, P = 0.013). CONCLUSIONS: We found high CoRE prevalence in malaria patients as determined by serology in the study region; cases were associated with a worse clinical outcome. Further prospective studies with samples from different infection sites and the use of molecular tools are needed to determine the clinical significance of these findings.

An aquatic host-guest complex between a supramolecular G-quadruplex and the anticancer drug doxorubicin.

We describe the synthesis of a fluorescent deoxyguanosine derivative that co-assembles (in water) with an unlabeled analogue into a heteromeric supramolecular G-quadruplex, which forms a host-guest complex with doxorubicin as evidenced by FRET experiments.

Description of a One-Year Succession of Variants of Interest and Concern of SARS-CoV-2 in Venezuela.

Some of the lineages of SARS-CoV-2, the new coronavirus responsible for COVID-19, exhibit higher transmissibility or partial resistance to antibody-mediated neutralization and were designated by WHO as Variants of Interests (VOIs) or Concern (VOCs). The aim of this study was to monitor the dissemination of VOIs and VOCs in Venezuela from March 2021 to February 2022. A 614 nt genomic fragment was sequenced for the detection of some relevant mutations of these variants. Their presence was confirmed by complete genome sequencing, with a correlation higher than 99% between both methodologies. After the introduction of the Gamma VOC since the beginning of the year 2021, the variants Alpha VOC and Lambda VOI were detected as early as March 2021, at a very low frequency. In contrast, the Mu VOI, detected in May 2021, was able to circulate throughout the country. After the detection of the Delta VOC in June 2021, it became the predominant circulating variant. With the arrival of the Omicron VOC in December, this variant was able to displace the Delta one in less than one month.

Introduction and rapid dissemination of SARS-CoV-2 Gamma Variant of Concern in Venezuela.

In less than two years since SARS-CoV-2 emerged, the new coronavirus responsible for COVID-19, has accumulated a great number of mutations. Many of these mutations are located in the Spike protein and some of them confer to the virus higher transmissibility or partial resistance to antibody mediated neutralization. Viral variants with such confirmed abilities are designated by WHO as Variants of Concern (VOCs). The aim of this study was to monitor the introduction of variants and VOCs in Venezuela. A small fragment of the viral genome was sequenced for the detection of the most relevant mutations found in VOCs. This approach allowed the detection of Gamma VOC. Its presence was confirmed by complete genome sequencing. The Gamma VOC was detected in Venezuela since January 2021, and in March 2021 was predominant in the East and Central side of the country, representing more than 95% of cases sequenced in all the country in April-May 2021. In addition to the Gamma VOC, other isolates carrying the mutation E484K were also detected. The frequency of this mutation has been increasing worldwide, as shown in a survey of sequences carrying E484K mutation in GISAID, and was detected in Venezuela in many probable cases of reinfection. Complete genome sequencing of these cases allowed us to identify E484K mutation in association with Gamma VOC and other lineages. In conclusion, the strategy adopted in this study is suitable for genomic surveillance of variants for countries lacking robust genome sequencing capacities. In the period studied, Gamma VOC seems to have rapidly become the dominant variant throughout the country.

Self-assembled cation transporters made from lipophilic 8-phenyl-2'-deoxyguanosine derivatives.

We have previously reported that 8-phenyl-2'-deoxyguanosine derivatives (8PhGs) are able to extract metal cations from an aqueous phase into an organic phase. Herein we report on the ability of 8PhGs to transport metal cations across a bulk lipophilic liquid membrane. The experiments were performed using lithium, sodium, potassium, and strontium picrate salts with the parent lipophilic Gi, two isomeric 8PhG derivatives, cis-dicyclohexano-18-crown-6 (CD18C6) and [2•2•2] cryptand as reference compounds. The relative amounts of the picrate salts were measured by UV spectroscopy in both, the source phase and the receiving phase over a period of 24 h. The results show that the transport efficiency of the self-assembled ionophores formed by 8PhGs is either similar or superior to that of CD18C6, and in all but one case higher than the parent compound Gi. The varying efficiencies between the derivatives can be attributed to the stability (kinetic and thermodynamic) and the different molecularities of the supramolecules formed by these 8PhGs. The ease of the synthesis of 8PhGs, their anion independent assembly and the fact that the transport efficiency can be modulated as a function of the structure of the 8PhGs bode well for the use of such compounds in the development of novel antimicrobial agents and cation sensing devices.

Solvent-induced high fidelity switching between two discrete supramolecules.

Here we show the reversible high fidelity switching between two discrete self-assembled supramolecules made from a lipophilic 8-phenyl-2'-deoxyguanosine derivative induced by an indirect solvent effect. A hexadecameric supramolecule containing four stacked tetramers is formed in acetonitrile aided by higher potassium concentrations. When the amount of weakly solvated potassium decreases, due the lower activity of potassium iodide in chloroform, an octamer is formed after the dissociation of the two outer tetramers in the hexadecamer. The switching process results from an unprecedented subtle interplay between the activity of potassium iodide and the steric crowding within the self-assembled structure. Besides the possible applications in nanoconstruction, this phenomenon sheds light into the mechanism of formation of self-assembled supramolecules made from guanosine derivatives.

Inverse association between insulin resistance and frequency of milk consumption in low-income Argentinean school children.

OBJECTIVE: To determine the association between milk consumption, lifestyle, components of the metabolic syndrome, and insulin resistance in school children. STUDY DESIGN: Students (n = 365 [175M]) age 10 +/- 2.3 years from 2 poor suburbs of Buenos Aires were examined for body mass index, waist circumference, blood pressure, and Tanner stage in April 2007. Fasting concentrations of lipids, insulin, and glucose were determined. Mothers completed questionnaires about their children's lifestyle. RESULTS: Approximately 14.0% of the children were obese, and 12.1% were overweight by use of norms from the Centers for Disease Control and Prevention. Half were at Tanner I. Mean values of waist circumference, systolic blood pressure, insulin resistance, and insulin were higher as subjects consumed more glasses of milk. Multiple regression analysis with insulin resistance as the dependent variable showed that there was a significant and positive association with triglyceridemia (beta = 0.007) and waist circumference (beta = 0.024), and a negative association with milk consumption (beta = -0.135) adjusted for blocks walked daily, TV viewing, soft drink consumption, parental educational level, sex, age, high-density lipoprotein (HDL) cholesterol, and systolic blood pressure (R(2) = 0.27). CONCLUSIONS: Increased milk consumption was associated with greater insulin sensitivity, suggesting that it might reduce the risk of type 2 diabetes.

Prevalence of anemia and deficiencies of iron, folic acid and vitamin B12 in an indigenous community from the Venezuelan Amazon with a high incidence of malaria.

The objective of this work was to determine the prevalence of anemia and deficiencies of iron, folic acid and vitamin B12 in Betania del Topocho, a Piaroa community from Estado Amazonas, Venezuela, a zone with a high incidence of malaria. The group studied included 184 subjects of all ages that assisted to the local health center for malaria diagnosis. Analysis performed included hematology by coulter counter, ferritin quantification by ELISA with monoclonal antibodies and folic acid and vitamin B12 determinations by an immunoradiometric assay. It was found that the prevalence of anemia was 89.6% and deficiencies of iron, folic acid and vitamin B12 affected 37.1,70.3 and 12.4% of the population studied, respectively. Plasmodium infection was detected by molecular diagnosis in 53.2% of the cases, and 86% of them were anemic. The highest incidence of anemia was found in children, with a prevalence of 100% in infants of both sexes. The high prevalence of anemia, iron and folic acid deficiencies found, indicates an important health and nutrition problem that should be immediately and properly addressed. The number of cases of anemia due to iron deficiency could be underestimated, since ferritin concentration increased as a acute phase protein, although prevalence data was also analyzed with a cutoff point of 30 microg/L for ferritin concentration.

Type 2 diabetes markers in indigenous Argentinean children living at different altitudes.

BACKGROUND: Exposure to hypoxia at high altitude is increasingly being recognized as a risk factor for metabolic diseases. OBJECTIVE: To determine the association between Type 2 diabetes (T2D) risk factors and altitude in two groups of Argentinean indigenous schoolchildren who live permanently at different altitudes. METHODS: This cross-sectional study compared 142 schoolchildren from San Antonio de los Cobres (SAC), 3750 m above sea level, with 171 from Chicoana (CH), 1400 m. Data for children's anthropometry, blood pressure and lipids, as well as mothers' height and weight were assessed. RESULTS: There was not a significant difference in age between SAC (9.0 + 2y) and CH (9.4 + 2y) children. However, mean children's weight (29 vs. 38 kg), height (130 vs. 138 cm), BMI (17 vs. 19 kg/m2), and HDL-C (46 vs. 48 mg/dL) were significantly lower in SAC than in CH, respectively. In contrast, systolic blood pressure (87 vs. 70 mmHg), cholesterol (157 vs. 148 mg/dL), and triglycerides (104 vs. 88 mg/dL) were significantly higher in SAC than in CH, respectively. There was not a significant difference in age (33.2 + 7y vs. 34.4 + 8y) and BMI (26.2 + 4y vs. 28 + 5y) between SAC and CH mothers. Multiple linear regression analyses showed that children's blood pressure (R2 = 0.38), triglycerides (R2 = 0.21), and HDL-C (R2 = 0.16) were significantly associated with altitude, adjusted for confounding variables. CONCLUSION: This study shows that indigenous Argentinean children living at 3750 meters have higher T2D risk compared with those living at 1400 meters above sea level.

Detection of the Omicron variant of SARSCoV-2 by restriction analysis targeting the mutations K417N and N440K of the spike protein / Detección de la Variante Ómicron del SARS-CoV-2 por análisis de restricción de dos mutaciones de la proteína de la espiga

Abstract By the end of 2021, the Omicron variant of concern (VOC) emerges in South Africa. This variant caused immediate concern, due to the explosive increase in cases associated with it and the large number of mutations it exhibits. In this study, the restriction sites that allow detecting the mutations K417N and N440K in the Spike gene are described. This analysis allows us to propose a rapid method for the identification of cases infected with the Omicron variant. We show that the proposed methodology can contribute to provide more information on the prevalence and rapid detection of cases of this new VOC.

Resumen Para finales de 2021 surge la variante de preocupación (VOC por sus siglas en inglés) Ómicron en Sudáfrica. Esta variante causó de forma inmediata preocupación, debido al aumento explosivo de casos asociados a ella y al gran número de mutaciones que exhibe. En este estudio, se describen los sitios de restricción que permiten detectar dos de estas mutaciones en el gen de la espiga, las mutaciones K417N y N440K. Este análisis permite proponer un método rápido para la identificación de casos infectados con la variante Ómicron. Mostramos que la metodología propuesta puede contribuir a proporcionar más información sobre la prevalencia y a detectar rápidamente los casos de esta nueva VOC.

Sub-lineages of the Omicron variant of SARS-CoV-2: characteristic mutations and their relation to epidemiological behavior / Sub-linajes de la variante Ómicron del SARS-CoV-2: mutaciones características y su relación con el comportamiento epidemiológico

Abstract By the end of 2021, the Omicron variant of SARS-CoV-2, the coronavirus responsible for COVID-19, emerges, causing immediate concern, due to the explosive increase in cases in South Africa and a large number of mutations. This study describes the characteristic mutations of the Omicron variant in the Spike protein, and the behavior of the successive epidemic waves associated to the sub-lineages throughout the world. The mutations in the Spike protein described are related to the virus ability to evade the protection elicited by current vaccines, as well as with possible reduced susceptibility to host proteases for priming of the fusion process, and how this might be related to changes in tropism, a replication enhanced in nasal epithelial cells, and reduced in pulmonary tissue; traits probably associated with the apparent reduced severity of Omicron compared to other variants.

Resumen A finales de 2021 surge la variante Omicron del SARS-CoV-2, el coronavirus responsable de la COVID-19, causando preocupación inmediata, debido al aumento explosivo de casos en Suráfrica, y a su gran cantidad de mutaciones. Este estudio describe las mutaciones características de la variante Ómicron en la proteína de la Espiga (S) y el comportamiento de las sucesivas olas epidémicas asociadas a la circulación de sus sub-linajes en todo el mundo. Las mutaciones en la proteína S descritas están relacionadas con su capacidad para evadir la protección provocada por las vacunas actuales, así como su posible susceptibilidad reducida a las proteasas del hospedero para la preparación del proceso de fusión. Se infiere cómo esto podría estar relacionado con su cambio en el tropismo, con una replicación mayor en las células epiteliales nasales y menor en el tejido pulmonar, rasgos probablemente asociados a su aparente menor gravedad en comparación con otras variantes.

Comparison Between HDL-C Levels in Argentine Indigenous Children Living at High Altitudes and U.S. Children.

BACKGROUND: Studies have shown low levels of high-density lipoprotein cholesterol (HDL-C) in indigenous children versus urban children from Argentina. We hypothesized that indigenous children living at high altitudes might have lower HDL-C levels compared with U.S. children, probably due to ambient hypoxia, lifestyle conditions, or ethnicity. This study was designed (1) to compare HDL-C levels in Argentinean indigenous children with those reported in the 2011-2012 National Health and Nutrition Examination Survey (NHANES) for U.S. children and (2) to determine the association between HDL-C and adiposity in both groups. SUBJECTS AND METHODS: A cross-sectional study of 1,232 (631 females) Argentinean indigenous schoolchildren (4-14 years old) from San Antonio de los Cobres (SAC) was performed between November 2011 and November 2014. Anthropometric measures were performed in the whole group and compared with those of 2,151 U.S. children (1,034 females). However, HDL-C concentrations were measured in 905 SAC children and compared with those of 1,451 U.S. children. Analyses were done incorporating sampling weights for age in both samples to obtain unbiased estimates. In the case of NHANES the weights provided by each individual in the 2011-2012 NHANES demographic file were used, whereas in the SAC sample the weights were obtained using the census data provided by the 2010 National Statistics and Censuses Institute of Argentina. RESULTS: The prevalence of overweight/obesity was significantly lower in SAC (135/1,232; 11%) than in the United States (759/2,151; 35%). However, the prevalence of low levels of HDL-C was significantly higher in SAC (298/905; 33%) than in the United States (142/1,451; 10%). The prevalence of low levels of HDL-C increased significantly in both groups as body mass index categories increased. Multiple logistic regression analysis showed that SAC children had nine and a half times the odds of having low levels of HDL-C compared with U.S. children, adjusted for confounding variables (odds ratio = 9.55; 95% confidence interval, 7.18-12.71). CONCLUSIONS: This study shows a high prevalence of low levels of HDL-C in indigenous Argentinean children 4-14 years of age living at high altitudes compared with U.S. children.

Waist Circumference Percentiles in Indigenous Argentinean School Children Living at High Altitudes.

BACKGROUND: Central obesity is associated with increased risk of type 2 diabetes. OBJECTIVES: The study objectives were to develop waist circumference (WC) percentiles, to determine if WC is associated with metabolic risk, and to compare our WC percentiles with those reported in the 2007-2010 National Health and Nutrition Examination Survey (NHANES). METHODS: A cross-sectional study of 1232 children (606 boys ) 5-14 years was performed from 2011 to 2014 in indigenous Koya children from northwestern Argentina. Anthropometric characteristics, glucose, lipids, and insulin levels were measured. Sex-specific reference percentiles were computed using the Lambda-Mu-Sigma (LMS) method. We obtained 2007-2010 NHANES data for comparison with our results. RESULTS: Compared with the NHANES 90th percentile, WC values for children in this study were lower by an average of 11.05 cm for girls and 12.66 cm for boys. The prevalence of low high-density lipoprotein cholesterol (HDL-C) was 11.8% in children with WC ≤50th percentile, 10.3% in children with WC >50th-70th percentile, 17.5% in children with WC >70th-90th percentile, and 21.3% in children with WC >90th percentile. The prevalence of high triglycerides (TG) was 19.5% in children with WC ≤50th percentile, 19.9% in children with WC >50th-70th percentile, 28.8% in children with WC >70th-90th percentile, and 39.7% in children with WC >90th percentile. Multiple logistic regression analyses showed that high TG values (>150 mg/dL) were significantly associated with WC [odds ratio (OR)] 1.05; 95% confidence interval (CI) 1.03-1.08; and low HDL-C values (<35 mg/dL) were significantly associated with WC (OR 1.04; 95% CI 1.01-1.06), adjusted for age and gender. CONCLUSION: We present for the first time WC reference data for indigenous Koya children ages 5-14 years. There was a significant association between WC and dyslipidemia in this community. Compared with the NHANES WC percentiles, our WC values were lower. These differences possibly reflect ethnicity or the lower prevalence of obesity.