Neonatal anthropometry of malformed newborns: A large South American population-based study.

BACKGROUND: Population-based anthropometric evaluation of malformed newborns is scarce. OBJECTIVES: To evaluate malformed newborns' foetal growth using the ICD 10 malformations' classification. METHODS: A study including 33,769 newborns (14,857 malformed and 18,912 nonmalformed), selected from 678,840 births from nine South American countries, period 2010-2018, was conducted. Prevalence of severe small and small for gestational age was calculated for malformed and nonmalformed newborns classified by preterm birth categories. Prevalence and relative risk (RR) with its 95% confidence interval (CI) were calculated. The associations between anthropometric phenotypes and congenital malformations were evaluated with generalized linear models. RESULTS: Prevalence of preterm and term severe small and small for gestational age newborns was higher in malformed than that in nonmalformed neonates. For grouped ICD 10 malformations categories, the RR for severe small for gestational age was 2.88 (95% CI 2.51, 3.30) and 2.10 (95% CI 1.92, 2.30) for small for gestational age. For at-term and preterm malformed newborns, the RR for severe small for gestational age was 2.21 (95% CI 1.87, 2.61) and 3.21 (95% CI 2.52, 4.10), respectively; for small for gestational age, the RR was 2.31 (95% CI 2.11, 2.53) for at-term newborns and 2.58 (95% CI 2.16, 3.08) for preterm ones. CONCLUSIONS: Prevalence and relative risk of severe small and small for gestational age vary according to the group of malformations and gestational age; they increase in congenital malformations of the nervous, respiratory and digestive systems, and in chromosomal abnormalities and are lower for malformations of eye, ear, face and neck and cleft lip and palate. Foetal growth considered together with malformed newborns' gestational age would allow for inferring different risks of morbidity and mortality.

Surnames and population structure in the Doctrine of Belén, Altos de Arica, Viceroyalty of Peru (1750-1813).

The analysis of multiple population structures (biodemographic, genetic and socio-cultural) and their inter-relations contribute to a deeper understanding of population structure and population dynamics. Genetically, the population structure corresponds to the deviation of random mating conditioned by a limited number of ancestors, by restricted migration in the social or geographic space, or by preference for certain consanguineous unions. Through the isonymic method, surname frequency and distribution across the population can supply quantitative information on the structure of a human population, as they constitute universal socio-cultural variables. Using documentary sources to undertake the Doctrine of Belén's (Altos de Arica, Chile) historical demography reconstruction between 1763 and 1820, this study identified an indigenous population with stable patronymics. The availability of complete marriage, baptism and death records, low rates of migration and the significant percentage of individuals registered and constantly present in this population favoured the application of the isonymic method. The aim of this work was to use given names and surnames recorded in these documentary sources to reconstruct the population structure and migration pattern of the Doctrine of Belén between 1750 and 1813 through the isonymic method. The results of the study were consistent with the ethno-historical data of this ethnic space, where social cohesion was, in multiple ways, related to the regulation of daily life in colonial Andean societies.

Proportionality indices, geographic altitude, and gestational age in newborns from Jujuy, Argentina.

BACKGROUND: There are several different proportionality indices (PRIs) to evaluate size at birth by gestational age (GA). Yet, the explanatory power of alternative PRIs has not been evaluated in highland (HL) populations. AIM: Evaluate the relative utility of three PRIs, weight to length ratio (W/L), body mass index (BMI), and ponderal index (PI), for assessing nutritional status in newborns (NBs) from highland (HL ≥ 2000 m) and lowland (LL < 2000 m) regions of the Jujuy Province of Argentina. SUBJECTS AND METHODS: Births were registered by the Ministry of Health (Jujuy, 2009-2014). Data were grouped according to HL and LL altitude groups based on of maternal residence. The main outcome measures were the PRIs W/L ratio, BMI, and PI. Percentiles were generated by the LMS method and compared with references. ANOVAs and Pearson correlations were used to examine the relationship between outcome measures with weight and length by altitude, sex, and GA. RESULTS: In both altitude zones, W/L and BMI increased with GA, while PI stabilized between 37th and 42th weeks. The LL sample had significantly higher values for all the PRIs from the 37th week of GA. In the HL sample, the 50th percentiles for all three PRIs were lower than the reference. Regardless of GA and altitude level, BMI showed the lowest correlation with length and the higher with the weight. CONCLUSION: The HL sample of term NBs had lower values for all PRIs compared to their LL counterparts. In both altitude zones, the BMI is the preferred PRI to evaluate the nutritional status.

Excess weight and thinness over two decades (1996-2015) and spatial distribution in children from Jujuy, Argentina.

BACKGROUND: The increase of excess weight around the world is progressive and sustained in children. This is the most prevalent form of malnutrition in this population and they represent the major public health problem in developed and developing countries. The aim of this study was to analyze the magnitude of change in thinness and excess weight prevalence in 4-7 years-old schoolchildren from Jujuy (Argentina), between 1996 and 2015 and to examine the association according to sex and school location. METHODS: Cross-sectional study. Data was obtained from databases of School Health programs and it is representative of the city school population. For the analysis, 31,014 schoolchildren between 4 and 7 years old were evaluated, 20,224 from the first period (1996-2001) and 10,790 from the second (2010-2015). The city was partitioned in three different areas determined by the rivers that cross it. Nutritional status was determined by BMI for age with the criteria suggested by the International Obesity Task Force. The percentage of malnutrition change between periods was calculated and a binomial regression model was adjusted. RESULTS: Between periods, a significant (p-value< 0.0001) increase in the prevalence of overweight from 15.1% (CI 14.6-15.6%) to 18.1% (CI 17.4-18.8%) and obesity from 5% (CI 4.7-5.3) to 10.7% (CI 10.1-11.3%), and a decrease of thinness prevalence from 6.3% (CI 6.0-6.7%) to 4.7% (CI 4.3-5.1%) were observed. The percentage of change in the prevalence of obesity was very high in all areas and in both sexes (103.5% girls; 125.6% in boys), being higher in the south for girls (122.4%) and in the north for boys (158.8%). Besides, being a boy was inversely associated with the presence of excess weight and, as the age increases, the presence of obesity does it too. By analyzing the effect of the school location, the south and north zones had an inverse association with the presence of obesity. The period has a direct association with the presence of excess weight. CONCLUSION: The study contributes with valuable information on the magnitude of the increase in obesity in schoolchildren and suggests a possible correlation with sex and spatial distribution in the capital city of Jujuy.

CONSANGUINITY BY RANDOM ISONYMY AND SOCIOECONOMIC DEVELOPMENT IN ARGENTINA: A POPULATION STUDY.

In human populations various flexible, labile and interdependent structures (genetic, demographic, socioeconomic) co-exist, each of which can be organized in an hierarchical order corresponding to administrative entities. The relationship between consanguinity, as estimated by random isonymy (F ST), and socioeconomic conditions was analysed at different levels of political and administrative organization in Argentina. From the surnames of 22,666,139 voters from the 2001 electoral roll, F ST was estimated for 510 Argentinian departments. Using a principal component analysis, a Socio-Demographic and Economic Indicator (SDEI), summarizing the effect of 22 socioeconomic and demographic variables at the departmental level, was computed. The relationship between departmental F ST and SDEI values was analysed for the whole nation and within regions using multiple regression analysis. The F ST presented a clinal distribution with the highest values in the north and west of the country, while SDEI expressed the opposite behaviour. A negative and significant correlation was observed between F ST and SDEI, accounting for 46% of the variation in consanguinity in Argentina. The strongest correlations of F ST with SDEI were observed in the Central, Patagonia and Cuyo regions, i.e. those with the highest values of SDEI and lowest values of F ST.

Geographical altitude, size, mass and body surface area in children (1-4 years) in the Province of Jujuy (Argentina).

BACKGROUND: Highland child populations show low growth rates. AIM: To evaluate the variation of size, mass and body surface area of Jujenean infants (1-4 years) as a function of geographic altitude. SUBJECTS AND METHODS: Nutritional status of 8059 healthy infants was determined based on weight and height data; body mass index, ponderal index, body surface area, body surface area/mass and ectomorphy were calculated. Variables were standardized with a provincial mean and WHO references. Data were grouped by age, sex and geographic altitude: Highlands (≥2500 masl) and Lowlands (<2500 masl). Chi-square, correlation and t-tests were applied. RESULTS: Highlands infants had higher prevalence of stunting, reduced height, weight, body surface area and ectomorphy; also higher body mass index, ponderal index and body surface area/mass. The population average z-score for height, weight and body surface area was positive in Lowlands and negative in Highlands. The opposite happened with body mass index, ponderal index and body surface area/mass. In Highlands and Lowlands the average z-score reference was negative for weight and height and positive for body mass index. Correlations between indices were high and significant, higher in Highlands. CONCLUSION: Jujenean children differ in size, mass and body surface area based on the geographical altitude and adverse nutritional and socioeconomic factors.

Weight and height percentiles calculated by the LMS method in Argentinean schoolchildren. A comparative references study.

BACKGROUND: The Argentinean population is characterized by ethnic, cultural and socio-economic diversity. AIM: To calculate the percentiles of weight-for-age (W/A) and height-for-age (H/A) of schoolchildren from Argentina employing the LMS method; and to compare the obtained percentiles with those of the international and national references. SUBJECTS AND METHODS: Anthropometric data of 18 698 students (8672 girls and 10 026 boys) of 3-13 years old were collected (2003-2008) from Buenos Aires, Catamarca, Chubut, Jujuy, La Pampa and Mendoza. Percentiles of W/A and H/A were obtained with the LMS method. Statistical and graphical comparisons were established with the WHO (international reference) and with that published by the Argentinean Paediatric Society (national reference). RESULTS: Differences in W/A and H/A, regarding the references, were negative and greater at the highest percentiles and in most of the age groups. On average, the differences were greater for boys than girls and for national than international references. CONCLUSION: The distribution of weight and height of schoolchildren, coming from most regions of the country, differs from those of national and international references. It should be advisable to establish a new national reference based on internationally recognized methodological criteria that adequately reflect the biological and cultural diversity of the Argentinean populations.

So close, so far away: analysis of surnames in a town of twins (Cândido Godói, Brazil).

Cândido Godói is a small Brazilian town known for high rates of twin birth. In 2011, a genetic study showed that this localized high rate of twin births could be explained by a genetic founder effect. Here we used isonymic analysis and surname distribution to identify population subgroups within 5316 inhabitants and 665 different surnames. Four clusters were constructed based on different twin rates (P < 0.001; MRPP test). Fisher's α and consanguinity index showed low and high values, respectively, corresponding with observed values in isolated communities with high levels of genetic drift. Values of A and B estimators confirmed population isolation. Three boundaries were identified with Monmonier's maximum difference algorithm (P = 0.007). Inside the isolated sections, surnames of different geographic origins, language, and religion were represented. With an adequate statistical methodology, surname analyses provided a close approximation of historic and socioeconomic background at the moment of colony settlement. In this context, the maintenance of social and cultural practices had strong implications for the population's structure leading to drift processes in this small town, supporting the previous genetic study.

A study of the population of Paraguay through isonymy.

In order to describe the isonymic structure of Paraguay, the distribution of 4,843,868 surnames of 2,882,163 persons was studied in the 18 departments and 237 districts of the nation. The correlations between isonymic and geographic distances for departments were r = 0.713 ± 0.052 for Euclidean distance, 0.597 ± 0.074 for Nei's and 0.582 ± 0.076 for Lasker's, and for districts r = 0.320 ± 0.007, 0.235 ± 0.009 and 0.422 ± 0.008, respectively. Average α was 151 for the entire country, 140.6 ± 6.5 for departments and 108.2 ± 2.7 for districts. The geographical distribution of districts'α is compatible with the settlement of subsequent groups of migrants moving from South towards the Centre and North of Paraguay. The geographical analysis of the first three components of Lasker's isonymy distance matrix is in agreement with such a process. The prevalence of Spanish-Amerindian ethnic groups and the relative absence of indigenous surnames (absence due mainly to the forced surname change of 1848) is in agreement with the diffusion of Spanish speaking males over a low-density area populated by indigenous groups. The present distribution of Y-markers and mt-markers in the available studies in most Latin American populations is compatible with this process.

Microevolutionary processes due to landscape features in the province of Jujuy (Argentina).

OBJECTIVES: We seek to evaluate the influence of a diverse and rugged physical environment on the genetic background of human populations. METHODS: We analyzed eight polymorphic Alu insertions in 226 individuals from Jujuy province (Argentina), which is composed of several regions with well-defined geographical features and marked contrasts between them associated with differences in altitude (range: 700-3300 m). This regional division was used to assess the spatial variation of the Alu diversity. RESULTS: Deviations from Hardy-Weinberg Equilibrium expectations resulting from heterozygous deficit were found for FXIIIB and PV92 in the highest subpopulations. Several Alu elements showed genetic heterogeneity between the highest region (La Puna) and the lowest regions (Valle and Selva). Similarly, a decreasing trend of the average heterozygosity according to altitude was found. Both the centroid method and the admixture analysis unveiled a gene flow above the average in lowland populations, indicating a higher proportion of foreign genes introduced by immigrants of European and African ancestry. Furthermore, several Alu frequency clines fitting the orientation of the altitude gradient were detected. CONCLUSIONS: Our study reveals a spatial patterning of the Alu diversity in Jujuy, most likely determined by disparities in landscape and environmental features between the different subregions. Differences in the physical environment would have drastically reduced the homogenizing effects of the gene flow and would have promoted genetic drift episodes in the highest subpopulations. Microevolutionary processes detected in Jujuy have played an important role in the shaping of the gene pool of the populations from this sub-Andean zone from Argentina.

Geographic patterns of genome admixture in Latin American Mestizos.

The large and diverse population of Latin America is potentially a powerful resource for elucidating the genetic basis of complex traits through admixture mapping. However, no genome-wide characterization of admixture across Latin America has yet been attempted. Here, we report an analysis of admixture in thirteen Mestizo populations (i.e. in regions of mainly European and Native settlement) from seven countries in Latin America based on data for 678 autosomal and 29 X-chromosome microsatellites. We found extensive variation in Native American and European ancestry (and generally low levels of African ancestry) among populations and individuals, and evidence that admixture across Latin America has often involved predominantly European men and both Native and African women. An admixture analysis allowing for Native American population subdivision revealed a differentiation of the Native American ancestry amongst Mestizos. This observation is consistent with the genetic structure of pre-Columbian populations and with admixture having involved Natives from the area where the Mestizo examined are located. Our findings agree with available information on the demographic history of Latin America and have a number of implications for the design of association studies in population from the region.

[Prevalence of malnutrition in institutionalized intellectually disabled patients]. / Prevalencia de malnutricion en pacientes con discapacidad intelectual institucionalizados.

As patients with intellectual and developmental disability (ID) may be more exposed to unfavorable factors, they are at higher risk of suffering nutritional alterations. Our objective was to determine prevalence of malnutrition in institutionalized patients with ID. An evaluation of the nutritional status through determination of transversal anthropometric parameters of weight (kg) and height (cm) was made on 614 individuals (352 men and 262 women) institutionalized at Colonia Nacional Montes de Oca, Buenos Aires Province, Argentina. Body mass index and prevalence of underweight, overweight and obesity cases by sex and ID type: mild, moderate and severe intellectual disability were determined. Regardless of sex, prevalence of underweight, overweight and obesity were of 2.9%, 30% and 27.7%, respectively. Regardless of degree of ID, greater prevalence of obesity (41.2%) was found amongst women, while overweight (34.7%) was more frequent amongst men. Taking the degree of ID and regardless of sex, greater prevalence of underweight was observed in severe ID, and overweight and obesity amongst mild ID. No any of the patients with mild ID presented underweight. Taking into account sex and ID, higher prevalence of underweight and overweight were observed amongst men with mild ID, (7% and 38.4%, respectively) and of obesity in women with moderate ID (44%). Results obtained would indicate the importance of caloric intake and energy consumption control in adults with ID, paying particular attention to life conditions and alimentary disorders in terms of the degree of ID and their multiple associated disabilities.

Fine-scale genomic analyses of admixed individuals reveal unrecognized genetic ancestry components in Argentina.

Similarly to other populations across the Americas, Argentinean populations trace back their genetic ancestry into African, European and Native American ancestors, reflecting a complex demographic history with multiple migration and admixture events in pre- and post-colonial times. However, little is known about the sub-continental origins of these three main ancestries. We present new high-throughput genotyping data for 87 admixed individuals across Argentina. This data was combined to previously published data for admixed individuals in the region and then compared to different reference panels specifically built to perform population structure analyses at a sub-continental level. Concerning the Native American ancestry, we could identify four Native American components segregating in modern Argentinean populations. Three of them are also found in modern South American populations and are specifically represented in Central Andes, Central Chile/Patagonia, and Subtropical and Tropical Forests geographic areas. The fourth component might be specific to the Central Western region of Argentina, and it is not well represented in any genomic data from the literature. As for the European and African ancestries, we confirmed previous results about origins from Southern Europe, Western and Central Western Africa, and we provide evidences for the presence of Northern European and Eastern African ancestries.

Isonymy structure of Buenos Aires city.

The isonymy structure of Buenos Aires was studied based on its surname frequency. Information on 2,552,359 voters of the 28 Buenos Aires districts was used to estimate Lasker's coefficient of relationship by isonymy (R(i)), surname diversity according to Fisher's alpha, the coefficient of consanguinity resulting from random isonymy (F), and Nei's, Lasker's and the Euclidean isonymy distances. These distances were correlated with geographic distances, which were calculated by assigning an arbitrary point to each district and measuring distances on a map of the city. The R(i) x 10(5) and F x 10(4) averages of the districts located south of Rivadavia Avenue were higher (R(i) = 66.08; F = 3.4) than those situated north of that avenue (R(i) = 46.60; F = 2.4) (p < 0.001). Fisher's alpha showed the opposite behavior (north, alpha = 1,055.5; south, alpha = 757.2). There was a significant correlation (p < 0.001) between geographic distance and Nei's and the Euclidean distances (0.496 and 0.503, respectively), but the correlation was not significant for Lasker's distance (0.051). These results indicate isolation by distance in the city of Buenos Aires and reveal subdivision of the metropolitan population, with greater consanguinity and a lesser variety of surnames in the districts located in the southern section of the city. This structure agrees with the fragmentation and social, cultural, and economic differences observed among the districts of this Latin American metropolis.

Geographic altitude, surnames, and height variation of Jujuy (Argentina) conscripts.

The height records of 48,589 conscripts born in Jujuy between 1870 and 1960 were examined in order to study the variation in adult male height (AMH) in terms of geographical altitude and surnames. Data were clustered by origin of surnames (divided into native and foreign names), decades, and according to the four Jujenean geographical regions distributed along an altitudinal gradient (Puna, Quebrada, Valle, and Ramal). The variation of surnames, geographical altitude, and time on human height were examined by analysis of variance. Regardless of the drafting year, individuals in the four regions bearing foreign surnames proved significantly taller (P < 0.001) than those who had a native surname. Average height, regardless of ethnic group, presented a reverse relationship to geographical altitude. A higher AMH was found in individuals bearing foreign surnames in Jujuy and lower ones in the population located in the highlands and bearing native surnames. Interregional and intergroup AMH variations would be affected by the complex interaction between geographical altitude and factors associated to it and by the ethnic characteristics of these population as well.

Brief communication: Restricted geographic distribution for Y-Q* paragroup in South America.

We analyzed 21 paragroup Q* Y chromosomes from South American aboriginal and urban populations. Our aims were to evaluate the phylogenetic status, geographic distribution, and genetic diversity in these groups of chromosomes and compare the degree of genetic variation in relation to Q1a3a haplotypes. All Q* chromosomes from our series and five samples from North American Q* presented the derivate state for M346, that is present upstream to M3, and determined Q1a3* paragroup. We found a restrictive geographic distribution and low frequency of Q1a3* in South America. We assumed that this low frequency could be reflecting extreme drift effects. However, several estimates of gene diversity do not support the existence of a severe bottleneck. The mean haplotype diversity expected was similar to that for South American Q1a3* and Q1a3a (0.478 and 0.501, respectively). The analysis of previous reports from other research groups and this study shows the highest frequencies of Q* for the West Corner and the Grand Chaco regions of South America. At present, there is no information on whether the phylogenetic status of Q* paragoup described in previous reports is similar to that of Q1a3* paragroup though our results support this possibility.

Dyslipidemia in schoolchildren with excess weight from Jujuy assessed by the program of school health / [Dislipemias en escolares jujeños con exceso de peso evaluados por el programa de salud escolar.]

Background: Excess weight (EW) and alterations in lipid metabolism constitute risk factors for cardiovascular disease in adults and children. Prevalence of dyslipidemia in schoolchildren from Jujuy with EW is analyzed in this study. Methods: Cross-sectional descriptive study of 891 schoolchildren 10-14 years old (367 girls; 524 boys) from the province of Jujuy (Northwestern Argentina). Prevalence of dyslipidemia for Overweight (OW) and Obesity (OB) were calculated, according to the International Obesity Task Force cut-off points. Prevalence of lipid alterations were analyzed and 7 dyslipidemic profiles were established. Comparisons and associations between variables were analyzed by Chi-square test. Crude and adjusted odds ratio were estimated from a logistic regressions. Results: Regardless of sex and nutritional status, 13.7%, 21.8%, and 16.5% of schoolchildren showed high values of total cholesterol, triglycerides, and LDL cholesterol, respectively, and 20.3% had low HDL cholesterol. Significantly higher values of HDL cholesterol were found in OW, and of triglycerides in OB. A significant association was recorded between OB and high triglycerides. Schoolchildren with OB have a 54% more chances of showing at least one lipid alteration. Conclusion: EW, and especially OB, constitutes an important risk factor in the development of dyslipidemia in schoolchildren from Jujuy.

Introducción: El exceso de peso (EP) y las alteraciones del metabolismo lipídico constituyen factores de riesgo de enfermedad cardiovascular en adultos y en niños. En este estudio se analiza la prevalencia de dislipemias en escolares jujeños con EP. Población y métodos: Estudio descriptivo, de corte transversal de 891 escolares entre 10-14 años (367 mujeres; 524 varones) de la provincia de Jujuy (Noroeste de Argentina). Se calcularon las prevalencias de dislipemias para Sobrepeso (SP) y Obesidad (OB), determinados según puntos de corte de la International Obesity Task Force. Se analizaron las prevalencias de alteraciones lipídicas y se establecieron 7 perfiles dislipemicos. Las comparaciones y asociaciones entre variables se analizaron con Chi cuadrado. Se estimaron odds ratio crudos y ajustados a partir de una regresión logística. Resultados: Independientemente del sexo y del estado nutricional el 13.7%, 21.8% y 16.5% de los escolares presentaron colesterol total, triglicéridos y colesterol LDL alto, respectivamente y el 20.3% colesterol HDL bajo. Se observaron valores significativamente más elevados de colesterol HDL en SP y de triglicéridos en OB. Se registró asociación significativa entre OB y triglicéridos altos. Los escolares con OB exhiben 54% más de chances de presentar al menos una alteración lipídica.. Conclusión: El EP, y sobre todo la OB, constituye un factor de riesgo importante para el desarrollo de dislipemias en escolares jujeños

Geographic altitude and prevalence of underweight, stunting and wasting in newborns with the INTERGROWTH-21st standard.

OBJECTIVE: To assess the prevalence and risks of underweight, stunting and wasting by gestational age in newborns of the Jujuy Province, Argentina at different altitude levels. METHODS: Live newborns (n=48,656) born from 2009-2014 in public facilities with a gestational age between 24+0 to 42+6 weeks. Phenotypes of underweight (2.000m.a.s.l. Maternal age, body mass index >35kg/m2, hypertension, congenital malformations, and prematurity were more strongly associated with underweight rather than stunting or wasting at ≥2.000m.a.s.l. CONCLUSIONS: Underweight, stunting, and wasting risks were higher at a higher altitude, and were associated with recognized maternal and fetal conditions. The use of those three phenotypes will help prioritize preventive interventions and focus the management of fetal undernutrition.

Epidemiology of sudden unexpected death in infancy in Argentina: secular trend and spatial variation. / Epidemiología de las muertes súbitas infantiles inesperadas en Argentina: tendencia secular y variación espacial.

Introduction: Infant mortality comprises deaths among infants younger than one year old. The proportion of sudden unexpected death in infancy (SUDI) varies by country and based on the cause of death. Objective: To describe the spatial and temporal variation of SUDI in Argentina between 1991 and 2014 according to the International Classification of Diseases, tenth revision. Materials and methods: Based on infant death data (provided by the Health Statistics and Information Department), we estimated the percentage of SUDI over the total number of infant deaths and the frequency of causes of death at a provincial, regional, and national level. The risk for death and the secular trend were estimated using a Poisson regression. The SaTScan software, v9.1.1, was used to detect clusters of districts where the percentage of SUDI was significantly different from the national percentage. Results: In Argentina, between 1991 and 2014, 267 552 infants younger than 1 year died; 7 % corresponded to SUDI; the secular trend of causes was negative and statistically significant; the risk for SUDI was 0.86, and a great spatial heterogeneity was observed. At a national level, the most common cause was sudden infant death syndrome, with inter-regional differences. In nine district clusters, the risk for SUDI ranged between 4.36 and 1.24, which is significantly different from the rest of the country. Conclusions: The proportion of SUDI and its causes show inter-regional heterogeneity; codes related to inaccurate diagnoses predominated in more unfavorable regions, while sudden infant death syndrome was prevalent in the more developed regions.

Introducción. La mortalidad infantil incluye defunciones de menores de un año. La proporción de muerte súbita inesperada infantil (MSII) varía entre países y según las causas de muerte consideradas. Objetivo. Describir la variación espacial y temporal de MSII en Argentina entre 1991 y 2014 utilizando la Clasificación Internacional de Enfermedades, décima revisión. Materiales y métodos. A partir de la información de defunciones infantiles (Dirección de Estadísticas e Información de Salud), se calculó el porcentaje de MSII sobre el total de muertes infantiles y la frecuencia de las causas que la componían a nivel nacional, regional y provincial. El riesgo de muerte y la tendencia secular se calcularon con regresión de Poisson. Para detectar agrupamientos departamentales con porcentajes de MSII significativamente diferentes a los nacionales, se utilizó el programa SaTScan v9.1.1. Resultados. En Argentina, entre 1991 y 2014, fallecieron 267 552 menores de un año; el 7 % fueron MSII; la tendencia secular de estas causas fue negativa y estadísticamente significativa; el riesgo de MSII fue de 0,86, y se observó una gran heterogeneidad espacial. A nivel nacional, la causa más frecuente fue síndrome de la muerte súbita del lactante, con diferencias interregionales. Nueve agrupamientos departamentales tuvieron riesgo de MSII entre 4,36 y 1,24, significativamente diferentes al resto del país. Conclusiones. La proporción de MSII y de las causas que la componen presenta heterogeneidad interregional con predominio de códigos relacionados con diagnósticos imprecisos en las regiones más desfavorecidas y de síndrome de muerte súbita del lactante en las más desarrolladas.

Reference percentiles for mid-upper arm circumference, upper arm muscle and fat areas in the Argentine child and adolescent population (4-14 years old). / Percentilos de referencia de la circunferencia y de las áreas muscular y grasa del brazo para la población infantojuvenil argentina (4-14 años).

INTRODUCTION: Mid-upper arm circumference (MUAC) is widely recognized as an adequate indicator of nutritional status. OBJECTIVE: To estimate the reference percentiles for MUAC, upper arm muscle area (UAMA), and upper arm fat area (UAFA) in the Argentine child and adolescent population using the LMS method (lambda, mu, sigma). MATERIALS AND METHODS: The sample was made up of schoolchildren aged 4.0-13.9 years living in Jujuy, Catamarca, Misiones, Buenos Aires, Mendoza, and Chubut. MUAC and tricipital skinfold anthropometric measurements were obtained between 2003 and 2008 as per standardized protocols. UAMA and UAFA were calculated, and percentiles by age and sex were estimated and compared using an analysis of variance. RESULTS: A total of 22 736 schoolchildren (11 397 boys and 11 339 girls) were included. The 50th percentile was higher for the MUAC and UAFA among girls and for the UAMA among boys. The MUAC curves showed sharper increases as of 7 years old in all percentiles among both boys and girls. A similar pattern was observed for the UAMA, with higher values among boys. Lastly, the UAFA showed a constant increase among girls and a stabilization among boys as of 11 years old. Differences for age were observed. CONCLUSIONS: The tabulated and plotted percentiles and the MUAC, UAMA, and UAFA may be used as local references for epidemiological and anthropological studies.

Introducción: La circunferencia del brazo (CB) se reconoce como buen indicador del estado nutricional. Objetivo: Estimar los percentilos de referencia para la CB y las áreas muscular (AM) y grasa (AG) del brazo en la población infantojuvenil argentina mediante el empleo del método LMS (lambda, mu, sigma, en inglés). Materiales y métodos: La muestra estuvo constituida por escolares de 4,0 a 13,9 años residentes en Jujuy, Catamarca, Misiones, Buenos Aires, Mendoza y Chubut. Las mediciones antropométricas de la CB y del pliegue tricipital se realizaron entre 2003 y 2008 siguiendo protocolos estandarizados. Se estimaron las AM, AG, se calcularon los percentilos por edad y sexo, y se compararon mediante el análisis de la varianza. Resultados: Se incluyeron 22 736 escolares (11 397 varones y 11 339 mujeres). Los valores correspondientes al percentilo 50 fueron superiores, en las mujeres, para CB y AG, y, en los varones, para AM. Las curvas de CB presentaron incrementos más marcados a partir de los 7 años en todos los percentilos, para ambos sexos. Un patrón similar se observó para AM, con valores superiores en los varones. Por último, el AG mostró aumento constante en las mujeres y estabilización en los varones a partir de los 11 años. Se observaron diferencias para la edad. Conclusiones: Los valores de percentilos, tabulados y graficados, de la CB y de las AM y AG del brazo pueden constituir una referencia local para estudios epidemiológicos y antropológicos.