Influence of maternal stature, pregnancy age, and infant birth weight on growth during childhood in Yucatan, Mexico: a test of the intergenerational effects hypothesis.

In developing nations, obesity has increased dramatically in the last decade, but a high prevalence of stunting still coexists. The intergenerational influences hypothesis (IIH) is one explanation for this. We test the IIH regarding variation in maternal stature, mother's age at pregnancy, and infant birth weight in relation to risk for overweight and stunting in 206 Maya children (4-6 years old) from Mérida, Yucatan, Mexico. The Maya children are compared with growth references (Frisancho 2008: Anthropometric Standards: An Interactive Nutritional Reference of Body Size and Body Composition for Children and Adults. Ann Arbor, MI: The University of Michigan Press. 335 pp) for height, weight, and body mass index (BMI). Almost 70% of the mothers are shorter than 150 cm. Mothers' height and child's birth weight predict overweight. Children with a mother shorter than 150 cm are less than half as likely (OR = 0.44) to be overweight compared to children whose mothers are equal to or taller than 150 cm. Children with birth weights below 3,000 g are only a third as likely to be overweight (OR = 0.28) than their peers within the range of normal birth weight (3,000-3,500 g). Sex of the child, mother's height, and birth weight predict stunting. Girls are only 40% as likely as boys to be stunted. Children with a mother below 150 cm are 3.6 times more likely of being stunted. Children with birth weights below 3000 g are over 3 times more likely to be stunted relative to children with birth weights within the normal range. Mother's age at pregnancy is not a predictor of overweight or stunting. Our findings conform the IIH and with similar studies of populations undergoing nutritional/epidemiological transitions from traditional to globalized lifestyles.

Prenatal compared with parental origins of adolescent fatness.

BACKGROUND: Differences in prenatal growth influence postnatal body fat. OBJECTIVE: The objective was to investigate the role of parental body composition on the "tracking" of adolescent fatness. DESIGN: The study population consisted of 1993 white subjects and their parents. Measurements were taken at birth and again at the age of either 15, 16, or 17 y. The newborns were classified in 3 groups: small for gestational age, appropriate for gestational age, and large for gestational age. The mothers and fathers of the adolescents were classified into low and high subgroups on the basis of measurements of body mass index (BMI). Similarly, the mothers of the adolescents were classified into lean and fat subgroups on the basis of measurements of triceps skinfold thickness. RESULTS: Heavy newborns became heavier or fatter adolescents only when the mother or father was also fat and, among heavy newborns, the risk of becoming fat adolescents was approximately 5.7 times higher when the mother was fat rather than lean. CONCLUSIONS: Large newborns become fat adolescents only when the mother or father is also overweight or fat (ie, has either a high BMI or large skinfold thickness). These findings suggest that fatness during adolescence is related to parental fatness but not to prenatal fatness. Therefore, preventing higher levels of adiposity among newborns is unlikely to reduce overall adiposity in adolescence.

Domestic biomass fuel combustion and chronic bronchitis in two rural Bolivian villages.

BACKGROUND: Chronic bronchitis is an important public health problem worldwide. A study was undertaken to examine the association between exposure to air pollution from domestic biomass fuel combustion and chronic bronchitis in two rural Bolivian highland villages: a village in which cooking is done exclusively indoors and a village in which cooking is done primarily outdoors. Apart from this difference, the villages were virtually identical in terms of socioeconomic status, climate, altitude, access to health care, and other potential confounders. METHODS: Pollution exposure was assessed by combining information on concentrations of particulate matter of <10 microm diameter (PM(10)) in 12 randomly selected households in each village in all potential microenvironments of exposure with time allocation information. The prevalence of chronic bronchitis was assessed using the British Medical Research Council's questionnaire on individuals >20 years of age in both villages (n = 241). RESULTS: Daily pollution exposure was significantly higher in the indoor cooking village (range for adults: 9840-15 120 microg-h/m(3)) than in the outdoor cooking village (range for adults: 5520-6240 microg-h/m(3)) for both seasons and for men and women. The overall prevalence of chronic bronchitis was 22% and 13% for the indoor and outdoor cooking villages, respectively. Logistic regression analysis, which excluded the few smokers present in the population, showed a 60% reduced risk of chronic bronchitis in the outdoor cooking village compared with the indoor cooking village (OR 0.4; 95% CI 0.2 to 0.8; p = 0.0102) after adjusting for age and sex. Individuals aged >40 years were 4.3 times more likely to have chronic bronchitis than the younger age group (OR = 4.3; 95% CI 2.0 to 9.3; p = 0.0002). There was no significant difference in the prevalence of chronic bronchitis in men and women. CONCLUSIONS: The results of this study suggest an association between chronic bronchitis and exposure to domestic biomass fuel combustion, but further large scale studies from other areas of the developing world are needed to confirm the association. Results from this and other studies will assist the development of culturally acceptable and feasible alternatives to the high exposure cooking stoves currently being used by most people worldwide.

Developmental components of resting ventilation among high- and low-altitude Andean children and adults.

This paper evaluates the age-associated changes of resting ventilation of 115 high- and low-altitude Aymara subjects, of whom 61 were from the rural Aymara village of Ventilla situated at an average altitude of 4,200 m and 54 from the rural village of Caranavi situated at an average altitude of 900 m. Comparison of the age patterns of resting ventilation suggests the following conclusions: 1) the resting ventilation (ml/kg/min) of high-altitude natives is markedly higher than that of low-altitude natives; 2) the age decline of ventilation is similar in both lowlanders and highlanders, but the starting point and therefore the age decline are much higher at high altitude; 3) the resting ventilation that characterizes high-altitude Andean natives is developmentally expressed in the same manner as it is at low altitude; and 4) the resting ventilation (ml/kg/min) of Aymara high-altitude natives is between 40-80% lower than that of Tibetans.

Study of growth in rural school children from Buenos Aires, Argentina using upper arm muscle area by height and other anthropometric dimensions of body composition.

The primary objective was to compare growth and body composition in an infantile rural population by means of the upper arm muscle area by height and other antropometric measurements. Research was carried out by way of a cross sectional study, including 80% (321 6-13 year olds) of the schoolchildren living in General Lavalle, a rural community of about 3000 inhabitants. The methods and procedures included the evaluation of mother's educational levels and anthropometric measurements. Height (H), weight, mid upper arm circumference, and triceps skinfold (TS) were measured. The body mass index (BMI), the upper arm muscle area (UAMA), the upper arm fat area (UAFA) and the upper arm muscle area by height (UAMAH) were calculated. Variables were grouped by gender and age and transformed into z-scores, using the US anthropometric standards as reference. The results showed that: (1) the mother educational status was, in relation to z-scores, as in an urban population, and (2) the z-scores for BMI, UAFA and TS were above the reference, while the ones for H, UAMA and UAMAH were below the reference. The differences between z-scores in relation to mother's educational levels were statistically significant (p < 0.05). UAMA was correlated strongly with H (r = 0.67). The children of General Lavalle tend to be fatty and overweight, while their muscle mass and H are proportionally low, but with values within the reference. Thus, low muscle mass and H are, in general terms, indicative of low protein reserves, the systematically low-anthropometry found for UAMAH suggests that this index should be used in conjunction with other indexes (e.g. BMI, UAFA) to obtain a more complete assessment of body composition and nutritional status.

[Anthropometric growth of the school population in rural and suburban areas of Durango, Mexico]. / Crecimiento antropométrico de la población escolar en zonas rurales y suburbanas de Durango, México.

The nutritional status of school children from the rural and suburban areas from the state of Durango. México, was determined using anthropometric evaluation, during the periods 92-93 and 93-94. The sample included a total of 1,033 school children, of which 504 were males and 529 females, ranging ages from 3 to 15 years. The results of the study indicate that compared to the international standards, linear growth and weight of the Durango children decline with age and accentuate theirself through time. On the other hand, growth in body mass index exhibits a lesser retardation than that of height by age and weight by age. Evaluation of the weight by height index indicated that about 3% of the school children has suffered from chronic undernutrition.

Developmental, genetic, and environmental components of aerobic capacity at high altitude.

The aerobic capacity of 268 subjects (158 males and 110 females) was evaluated in La Paz, Bolivia situated at 3,750 m. The sample included 1) 39 high altitude rural natives (all male); 2) 67 high altitude urban natives (32 male, 35 female); 3) 69 Bolivians of foreign ancestry acclimatized to high altitude since birth (37 male, 32 female); 4) 50 Bolivians of foreign ancestry acclimatized to high altitude during growth (25 male, 25 female); and 5) 42 non-Bolivians of either European or North American ancestry acclimatized to high altitude during adulthood (25 male, 18 female). Data analyses indicate that 1) high altitude urban natives, acclimatized to high altitude since birth or during growth, attained higher aerobic capacity than subjects acclimatized to high altitude during adulthood; 2) age at arrival to high altitude is inversely related to maximum oxygen consumption (VO2 max) expressed in terms L/min or ml/min/kg of lean body mass, but not in terms of ml/min/kg of body weight; 3) among subjects acclimatized to high altitude during growth, approximately 25% of the variability in aerobic capacity can be explained by developmental factors; 4) as inferred from evaluations of skin color reflectance and sibling similarities, approximately 20 to 25% of the variability in aerobic capacity at high altitude can be explained by genetic factors; 5) except among the non-Bolivians acclimatized to high altitude during adulthood, the aerobic capacity of individuals with high occupational activity level is equal to the aerobic capacity of high altitude rural natives; and 6) the relationship between occupational activity level and aerobic capacity is much greater among subjects acclimatized to high altitude before the age of 10 years than afterwards. Together these data suggest that the attainment of normal aerobic capacity at high altitude is related to both developmental acclimatization and genetic factors but its expression is highly mediated by environmental factors, such as occupational activity level and body composition.

Selection on maternal and neonate size at birth.

Neonatal size is an important factor in determining the survivorship of infants within the first month of life. Because maternal size has an influence on neonatal size, selection should operate on those characters correlated with birth weight and gestational age, including maternal prepregnancy weight, height, and age. In the present study we use a path-analysis approach to examine the operation of selection on both neonatal and maternal size. We found that neonatal survivorship depends not only on the size of the infant at birth but also on a negative allometric relationship between the size of the neonate and the size of the mother. Thus, although the size of the mother has no direct effect on neonatal mortality, the mothers of surviving infants tend to be smaller relative to the size of their neonate. This may provide a mechanism whereby selection maintains a balance between maternal size and neonate size.

Adquisición de la adaptación fisiológica a la altura / Physiology adaptation at high altitude

El estres de la baja presión del oxígeno presente en la altura requiere una respuesta conjunta al sistema cardiorespiratorio. Por tanto las investigaciones de altura han estado dirigidas a determinar las características respiratorias, cardíacas y hematológicas de los visitantes y de los nativos a la altura. Durante los últimos años las investigaciones conducidas tanto en los Andes Americanos como en las HImalayas permiten determinar el proceso de adaptación fisiológica a la altura. En esta presentación se hace una revisión de los estudios realizados en los Andes Americanos y los Himalayas con el propósito de demostrar que una adapatción completa desde el punto de vista funcional es adquirida durante el proceso de desarrollo y crecimiento. Se presenta, además, las diferencias que existen entre una adaptación adquirida durante el estado adulto y aquel producido durante el período de crecimiento, concluyendo con un esquema general acerca de los mecanismos que operan para una adaptación fisiológica a la altura.

Decreased stature associated with moderate blood lead concentrations in Mexican-American children.

The relationship of blood lead concentration to stature was evaluated by examining data from a sample of 1454 Mexican-American children aged 5-12 y, derived from the data sets of the Hispanic Health and Nutrition Examination Survey (HHANES) conducted in 1982-1984. The results indicate that there is an inverse relationship between blood lead concentration in the range 0.14-1.92 mumol/L with stature. The present finding suggests that growth retardation may be associated even with moderate concentrations of blood lead. Therefore, permissible exposure levels of lead for children deserve reexamination in light of the present analysis.

Origins of differences in hemoglobin concentration between Himalayan and Andean populations.

Mean hemoglobin concentration of 3511 adult males derived from 19 studies of Andean male permanent residents and 10 studies of Himalayan male permanent residents were compared with reference to partial pressure of inspired oxygen. The regression equation (weighted for sample size) of PIO2 and hemoglobin concentration of the Andean miners is significantly (P less than 0.01) greater than that of the Andean and Himalayan non-miners. However, the relationship of PIO2 and Hb is similar in the non-mining Andean and Himalayan samples. These findings suggest that the observed differences in hemoglobin concentration between Andean and Himalayan samples are due, in part, to the inclusion of miners in the Andean samples. The higher barometric pressure associated with the north latitude location of the Himalayans may also contribute to decrease the hypoxic stress in the Himalayas. The present data suggest that Andeans and Himalayans have a similar hemopoietic response to hypoxic stress.

Standards of arm muscle by stature for the assessment of nutritional status of children.

This study is based on a sample of 9,134 children ranging in age from 2 to 17 years from which the excessively lean and fat children by skinfold thickness were excluded. This sample was derived from the combined data sets of the first and second National Health and Nutrition Examination Surveys (NHANES I and II) of 1971-1974 and 1976-1980. Means and percentiles of upper arm muscle area were calculated for 3 cm increments in stature from 84 to 184 cm for boys and from 84 to 176 cm for girls. Based on means, Z-score units, and percentile ranges of upper arm muscle area by stature, five operational categories of nutritional status have been established. It is recommended that these standards and this classification system be used to supplement current standards of weight for age and weight for height in order to obtain a more complete assessment of body composition and nutritional status.

Developmental and nutritional determinants of pregnancy outcome among teenagers.

To investigate the determinants of low birth weight in infants born to adolescent mothers, we studied the obstetric population attended at the Maternity Hospital of Lima, Peru. From this population, 1256 gravidas, ranging in age from 12 to 25 years, volunteered to participate in this study. Anthropometric and biochemical measurements were used to evaluate the nutritional status and physiological maturity of the mother and newborn. For analytical reasons the young teenaged mothers (less than 15 years) were classified as either still-growing or having completed their growth, depending on their height relative to their parents' height. Similarly, the young teenagers were classified as either gynecologically immature or gynecologically mature depending on whether their gynecological age was less than or greater than 2 years. Our results indicate that young still-growing teenagers, even when matched for nutritional status, have smaller newborns than adult mothers. The data also demonstrate that maternal gynecological age per se does not affect prenatal growth. As inferred from multivariate analyses, it appears that the reduction in birth weight among young teenagers can be explained in part by a decreased net availability of nutrients resulting from the competition for nutrients between the mother's growth needs and the growth needs of her fetus and by an inability of the teenage placenta to maintain placental function adequately for active fetal growth.

Influence of growth status and placental function on birth weight of infants born to young still-growing teenagers.

To investigate the determinants of fetal maturation of infants born to adolescent mothers, we studied the obstetric population attended at the Maternity Hospital of Lima, Peru. From this population we selected for inclusion in this study a sample of 412 adolescent mothers ranging in age from 13 to 15 yr. These subjects were selected because the anthropometric measurements of their parents were obtained at the time the adolescents were being attended for delivery. Based on the height measurements of the teenagers' mothers and fathers, the adolescents were classified as either still growing or growth completed depending on whether their height was less or greater than their mothers' height. Infants of young adolescent mothers who had not completed their expected growth in height were significantly lighter in birth weight than those born to adolescent mothers who had completed their growth. Multiple regression and path analyses revealed that the effects of weight gain and placenta weight on birth weight were more effective among the infants born to adolescent mothers who had not completed their growth in height. These data suggest that the reduction in birth weight among immature still-growing adolescents may result from both a decreased net availability of nutrients and/or an inability of the placenta to function adequately for active fetal growth, which results in a retarded fetal growth.

New standards of weight and body composition by frame size and height for assessment of nutritional status of adults and the elderly.

The study includes measurements of height, weight, triceps skinfold, subscapular skinfold, upper arm circumference, and elbow breadth of a cross-sectional multiracial sample of 21,752 subjects aged 25 to 74 yr derived from the data sets of the first and second National Health and Nutrition Examination Surveys (NHANES I and NHANES II). Based on these data, percentiles of weight, skinfolds, and bone-free upper arm muscle area by height, sex, and frame size were established for all races combined in two groups: adults aged 25 to 54 yr and the elderly aged 55 to 74 yr. These new standards can be used to differentiate those who are at risk of being obese and undernourished. It is recommended that assessment of anthropometric nutritional status and health status of contemporary adult and elderly populations be made with reference to the present standards in conjunction with age correction factors.