The relationship between iron deficiency and anemia in Venezuelan children.

The iron status of 3228 subjects from the nutrition survey Proyecto Venezuela was studied. The sample included children from 1 to 16 y of age grouped by age and sex. Values for three indicators of iron status were compared: hemoglobin concentration, serum ferritin concentration, and percentage saturation of serum transferrin. In all groups there was a strong overlap in the hemoglobin concentration distribution curves for non-iron-deficient and iron-deficient subjects classified as such according to the other two indexes. The prevalence of iron deficiency ranged from 35% in 1-3 y olds to 10% in adolescent males, the values being almost identical in the nonanemic group compared with the total population. In the different groups, 80-97% of the subjects with abnormal values of at least one of these two indexes were not anemic. The difficulties involved in establishing a state of iron deficiency according to these indexes are discussed.

Daily physiological iron requirements in children.

Median daily iron absorption was determined in iron-replete males and females between 2 and 19 years of age from the upper and lower socioeconomic strata of the Venezuelan population. A comparison was made with iron absorption of well-nourished children, on the basis of hematological and anthropometric reference values from the U.S. The median absorption level, which was calculated from the increase in total body iron due to growth and the daily losses through exfoliation and menstruation, was also used to estimate the requirements of 95% of the population. When the requirements were expressed in terms of body weight, no significant difference in iron absorption was observed between the three Venezuelan and one U.S. groups, ranging from about 30 to 38 micrograms/kg/day in both sexes between 4 and 16 years of age. However, when the requirements were expressed without division by the weight factor, the requirements of the better nourished groups were somewhat higher than those of the Venezuelan lower socioeconomic population with, in addition, a threefold variation over the 5 to 16 year age range. These findings suggest that the total iron requirements of children at a certain age may be most adequately expressed in terms of the optimal body weight for that age.

[Relation of fat consumption to colorectal cancer mortality in a Venezuelan population]. / Relación entre el consumo de grasas y la mortalidad por cáncer colorrectal en la población venezolana.

Epidemiologic and experimental studies have pointed to an association between fat intake and colorectal carcinogenesis. In the present work we have studied the correlation between fat intake and mortality caused by colorectal cancer in the venezuelan population. For this purpose, we have calculated the correlation coefficients between the ingestion of total fat, visible fat (vegetable oil, margarine, butter, mayonnaise) as well as non-visible fat (that contained in other foods) and the mortality rate by colorectal cancer with data from nine venezuelan states and geographical regions. The highest lipid consumption and mortality rates were observed in the more developed states. There was a positive and significant correlation between total as well as visible fat consumption and colorectal cancer mortality (r = 0.756 p < 0.02, and r = 0.958, p < 0.001; respectively). In contrast, there was no significant correlation between the consumption of non visible fats and colorectal mortality (r = 0.543, p < 0.05). More than 80% of the visible fats ingested in Venezuela are constituted by vegetable oil and margarine, which contain a high proportion of polyunsaturated fatty acids. Based on the above, is possible to infer that colorectal carcinogenesis in Venezuela is associated to the uptake of unsaturated fat, and that measures leading to the prevention of this disease should be based on the reduction in the consumption of total and unsaturated lipids.

[Comparative study of height and age at menarche according to the socioeconomic level in Venezuela]. / Estudios comparados de la estatura y edad de la menarquia según estrato socioeconomico en Venezuela.

This is a retrospective study based on growth and development data published in Venezuela by various authors in the period 1936-1978. The data on height for males of the middle and high socioeconomic strata show growth curves which are very similar to the standards for British children. Likewise, the girls of the same socioeconomic condition follow the British standards, but only up to about 10-12 years of age. After that age, the girls studied by the Venezuelan authors, show a pattern of early maturation with a corresponding lower adult height compared with their British counterparts. There were differences in the growth curves according to the socioeconomic strata. These differences were more marked in the girls data. A secular increase for height was discerned, from the published data, in all socioeconomic strata and in both sexes. The data on sexual maturation showed a tendency for progressively early menarche in Venezuelan girls. These changes in growth in height and age of menarche were more notorious and came about at an earlier age in the upper socioeconomic strata. They were less marked, not constant, and came about later in the lower socioeconomic groups. The secular changes in height and sexual maturation apparent from these data, could be explained by an improvement in the environmental conditions, especially nutrition and hygiene of the population, and also be genetic heterosis from European immigration and with improvement in communications.

PIP: A review of trends in height and weight at menarche in Venezuela is presented using data from studies published during the period 1936 to 1978. Variations by socioeconomic status are identified and discussed. (summary in ENG)

[Hematologic profile and absorption of iron from diets consumed by a population of low socioeconomic level of 2 Venezuelan states]. / Perfil hematológico y absorción del hierro de dietas que consume la población de estrato socioeconómico bajo de dos estados de Venezuela.

Hematologic studies carried out in inhabitants of the State of Carabobo revealed that 19% of the subjects studied presented iron deficiency, this being more prominent in women and in children. Iron deficiency anemia was absent in men, while in the other groups its frequency, as registered, was from 5 to 13%. Tests for iron absorption from foods which form the average diet of the population in the Carabobo State, and the diet consumed by adults from the low socioeconomic strata in the States of Carabobo and Yaracuy, demonstrated that in normal subjects, bioavailability is lower than physiological requirements of men, women and children. In the iron-deficient subjects, its bioavailability can cover physiological needs. It is estimated that an important proportion of the population strata consuming such diets, suffer from iron nutritional deficiency, especially women during the reproductive age, and children.

[Requirements of nutrients which participate in erythropoiesis]. / Requerimientos de nutrientes que participan en la eritropoyesis.

Proteins, some minerals and vitamins, play important roles in erythropoiesis and the survival of the red blood cell. This article deals specifically with the physiological requirements and recommended intakes of iron, folate and vitamin B12. A comparison of the physiologic iron requirements according to age and sex, and the amount of iron which is actually absorbed from the diets consumed by the lower socioeconomic strata of the Venezuelan population; indicates that these diets do not satisfy the requirements at all ages. Such disparity is most marked in children below three years of age, in adolescents and in women during their reproductive age. Failure to do so leads to varying degrees of iron deficiency. This low bioavailability of the Venezuelan diet is also observed in other Latin American diets consumed by the same low socioeconomic strata, which explains the high prevalence of iron-deficiency anemia in the vulnerable groups. The low intake of fruits and vegetables by the lower socioeconomic strata of the Latin American population prevents these sectors from consuming an adequate intake of folate, failing to fulfill the daily recommended intake (3.3 - 3.6 micrograms/kg body weight). This situation is aggravated in pregnant and lactating women who require an additional intake of 300 micrograms and 100 micrograms, respectively. Prevalence of folate deficiency in the first stage may be in the order of 30% in some regions. In the second stage of deficiency, characterized by megaloblastic changes in the bone marrow and an erythrocyte folate concentration of less than 50 micrograms/lt, it could be as high as 40% in pregnant women. Nutritional vitamin B12 deficiency does not constitute a health problem in Latin America. Various surveys in the lower socioeconomic strata have reported normal or higher than normal serum B12 concentrations, compared to well-nourished populations.

Selenium status of children living in seleniferous areas of Venezuela.

Selenium was measured in red blood cells, serum and hair of children and in breast milk of mothers in seleniferous areas of Venezuela by means of neutron activation analysis. Signs of selenosis were observed only in a few cases. Reduction in the rate of growth is discussed with respect to unequal local nutritional conditions during the growth period.

Colonia Tovar: the history of a semi-isolated Venezuelan population of German ancestry described by HLA class I genes.

The history of Colonia Tovar is very complex, being the home of descendants of only a small fraction of immigrants arriving to the South American continent from a specific region of Germany, with a restricted number of founders, small population size and consanguineous mating, experiencing isolation for 100 years, with later migrations, a low rate of population growth and a high mean number of children per couple. How complex is its genetic structure? Do the highly polymorphic HLA genes reflect its history and confirm the story of this population described by other genes? Several studies have been made in this population, but we describe for the first time the HLA Class I variability in the population of Colonia Tovar using PCR-SSOP. Random genetic drift, founder effect and gene flow could explain the HLA allele and haplotype frequencies observed in this population but alleles at the class I loci were insufficient to identify the German origin of the community established through history. This agrees with findings obtained testing other genetic systems (ACP, AK, ESD, G6PD, GLO, PGM, PGD, ALB, CP, HP, TF), but the HLA-typing results indicate that the original gene pool has been diluted due to gene flow from the surrounding Mestizo population.

Patrones de crecimiento de los venezolanos; dimorfismo sexual y ritmo de maduración / Patterns of growth of the venezuelan sexual dismorphism and rhythm of maturers

Se presentan algunos resultados del Proyecto Venezuela (1981-1987) y del Estudio Longitudinal del Area Metropolitana de Caracas (1976-1983). Las niñas iniciaron el brote puberal (BP) en talla y peso a los 9 1/2 años y alcanzaron la edad del punto de velocidad máxima (EPVM) a los 11 1/2 y 12 años, respectivamente, e iniciaron el desarrollo sexual (GM2) más de 1 año antes que el de los varones (G2:11 1/2 años). Las niñas resultaron más altas y pesadas entre los 11 y 13 años predominio puberal precoz debido al tempo rápido de las venezolanas- los hombres terminaron 12 1/2 cm y 8 Kg más altos y pesados a los 19 años. La secuencia de eventos: EPVM talla