Inequalities in adiposity trends between 1979 and 1999 in Guatemalan children.

BACKGROUND: Guatemala suffered from civil war and high levels of inequality and childhood stunting in the second half of the 20th century, but little is known about inequalities in secular trends in adiposity. OBJECTIVES: To investigate differences in childhood body mass index (BMI) and skinfold thickness trajectories from 1979 to 1999 between three groups of children: High socioeconomic position (SEP) Ladino, Low SEP Ladino, and Low SEP Indigenous Maya. METHODS: The sample comprised 19 346 children aged 7-17 years with 54 638 observations. The outcomes were height, BMI, triceps skinfold thickness (TST), and subscapular skinfold thickness (SST) Z-scores according to the Centers for Disease Control and Prevention (CDC) references. Sex-specific multilevel models were used to estimate and compare mean trajectories from 1979 to 1999 between the three groups. RESULTS: Mean Z-scores were always highest for High SEP Ladino children and lowest for Low SEP Maya children. Despite their very short stature, the Low SEP groups had SST trajectories that were above the 50th centile. The BMI trajectories were relatively flat and within one major centile band of the CDC median, with differences between the three groups that were small (0.2-0.3 Z-scores) and did not attenuate over time. Conversely, the TST Z-score trajectories demonstrated larger positive secular trends (e.g., from -1.25 in 1979 to -0.06 in 1999 for Low SEP Maya boys), with differences between the three groups that were large (0.5-1.2 Z-scores) and did attenuate over time (in boys). Secular trends and between-group difference in the SST Z-score trajectories were less pronounced, but again we found stronger evidence in boys that the estimated inequalities attenuated over time. CONCLUSIONS: Secular trends and inequalities in skinfolds differ from those for BMI in Guatemalan children. Differences between groups in skinfolds attenuated over time, at least in boys, but whether this is good news is questionable given the very short stature yet relatively large subscapular skinfolds of the Low SEP groups.

What makes people grow? Love and hope.

BACKGROUND: Hope and love are popular themes of literature and art in many human societies. The human physiology of love and hope is less well understood. This review presents evidence that the lack of love and/or hope delays growth disturbs development and maturation and even kills. MAIN BODY: Love and hope intersect in promoting healthy human development. Love provides a sense of security and attachment, which are necessary for healthy physical, cognitive, and emotional development. Hope provides a sense of optimism and resilience in the face of adversity. Loving relationships can foster a sense of hope in individuals and in society by providing support systems during difficult times. Similarly, having a sense of hope can make it easier to form loving relationships by providing individuals with the confidence to connect with others. Hope and love are the fundamental basis of human biocultural reproduction, which is the human style of cooperation in the production, feeding, and care of offspring. Examples are given of the association between human growth in height with love and hope, including (1) the global "Long Depression" of 1873-1896, (2) "hospitalism" and the abuse/neglect of infants and children, (3) adoption, (4) international migration, (5) colonial conquest, and (6) social, economic, and political change in Japan between 1970 and 1990. CONCLUSION: Overall, this review suggests that love and hope are both critical factors in promoting healthy human development and that they intersect in complex ways to support emotional well-being.

Stress exposure in specific growth periods associates with children's weight, height, and body mass index.

OBJECTIVES: We investigate associations between children exposure to stressful events, considering: (1) the period in which the event took place, (2) the type of event, and (3) the cumulative effect of the events on children's weight, height and body mass index (BMI). METHODS: A total of 8429 Portuguese children (3349 exposed to at least one stressful event during their lifetime; 50.2% males; mean age = 7.21 ± 1.85 years) were included in the analysis. The occurrence of stressful (i.e., adverse) events was reported in a parental questionnaire; children's weight and height were objectively measured. RESULTS: When the stress event took place in the first 2 years of life, compared with during pregnancy or after the 2 years, children were shorter; but the association was weak and only significant for boys. After adjustment for child's birthweight, gestational age, breastfeeding duration, number of siblings, and father's education, the experience of 3+ stressful events (vs. 1 or 2) was associated with higher weight and height in boys. No interaction effect was found between stress and BMI. DISCUSSION: We found some evidence of associations between exposure to stressful events and physical growth of boys. We highlight the complex relationship between exposure to stressful experiences and children's physical growth, particularly the different effects of specific characteristics of the stress event and the sex differences.

Bergmann's rule is a "just-so" story of human body size.

Carl Bergmann was an astute naturalist and physiologist. His ideas about animal size and shape were important advances in the pre-Darwinian nineteenth century. Bergmann's rule claims that that in cold climates, large body mass increases the ratio of volume-to-surface area and provides for maximum metabolic heat retention in mammals and birds. Conversely, in warmer temperatures, smaller body mass increases surface area relative to volume and allows for greater heat loss. For humans, we now know that body size and shape are regulated more by social-economic-political-emotional (SEPE) factors as well as nutrition-infection interactions. Temperature has virtually no effect. Bergmann's rule is a "just-so" story and should be relegated to teaching and scholarship about the history of science. That "rule" is no longer acceptable science and has nothing to tell us about physiological anthropology.

Use of joinpoint regressions to evaluate changes over time in conscript height.

OBJECTIVES: Cohort variation in adult height expresses both the impact of socio-economic change on human biology in a wide temporal perspective and social inequalities within populations. We aimed to test the use of joinpoint regressions to identify periods in which changes in height trends were statistically significant. METHODS: Data correspond to the height recorded in Madrid City (Spain) for 65 313 conscripts between 1936 and 1974 (cohorts from 1915 to 1953), a period of social and political turmoil. Secular trends in height were analyzed in eight districts with contrasting socio-economic conditions, grouped in two categories, lower-class and middle- and upper-class. Trends in height were evaluated by quadratic regressions and by joinpoint regressions to identify the cut-off years when trends changed significantly. RESULTS: Height increased in both socio-economic categories of districts, more among conscripts from the lower-class ones. However, results clearly show differences in trends according to district of residence. Whereas the increase in height in conscripts from the middle- and upper-class districts was steady, it was slower in those from the lower classes, with declines in height during the Civil War and first years of the Franco dictatorship. CONCLUSIONS: Joinpoint analysis reveals the association between urban living conditions and adult height, and that the disparities intensified during critical historical periods of Spain.

Fear, violence, inequality, and stunting in Guatemala.

BACKGROUND: Stunting is defined by the public health community as a length- or height-for-age <-2 SD of a growth standard or reference and is claimed to be caused by poor nutrition, repeated infection, and inadequate psychosocial stimulation. MATERIAL AND METHODS: Stunting is common at all income levels in middle- and low-income countries. At the higher income levels, stunting is unlikely to be caused by nutrient deficiency or infectious disease. RESULTS: In Guatemala, 17% of <5-year-olds in the highest family income quintile are stunted. Guatemala has a history of violence from armed conflict, current-day social and economic inequalities, government corruption, and threat of kidnapping for the wealthiest families. DISCUSSION AND CONCLUSION: The high level of persistent violence creates an ecology of fear, an extreme range of inequalities in Social-Economic-Political-Emotional resources, and biosocial stress that inhibits skeletal growth and causes stunting for people of all income levels.

Maternal Height-standardized Prevalence of Stunting in 67 Low- and Middle-income Countries.

BACKGROUND: Prevalence of stunting is frequently used as a marker of population-level child undernutrition. Parental height varies widely in low- and middle-income countries (LMIC) and is also a major determinant of stunting. While stunting is a useful measure of child health, with multiple causal components, removing the component attributable to parental height may in some cases be helpful to identify shortcoming in current environments. METHODS: We estimated maternal height-standardized prevalence of stunting (SPS) in 67 LMICs and parental height-SPS in 20 LMICs and compared with crude prevalence of stunting (CPS) using data on 575,767 children under-five from 67 Demographic and Health Surveys (DHS). We supplemented the DHS with population-level measures of other child health outcomes from the World Health Organization's (WHO) Global Health Observatory and the United Nations' Inter-Agency Group for Child Mortality Estimation. Prevalence of stunting was defined as percentage of children with height-for-age falling below -2 z-scores from the median of the 2006 WHO growth standard. RESULTS: The average CPS across countries was 27.8% (95% confidence interval [CI], 27.5-28.1%) and the average SPS was 23.3% (95% CI, 23.0-23.6%). The rank of countries according to SPS differed substantially from the rank according to CPS. Guatemala, Bangladesh, and Nepal had the biggest improvement in ranking according to SPS compared to CPS, while Gambia, Mali, and Senegal had the biggest decline in ranking. Guatemala had the largest difference between CPS and SPS with a CPS of 45.2 (95% CI, 43.7-46.9%) and SPS of 14.1 (95% CI, 12.6-15.8%). Senegal had the largest increase in the prevalence after standardizing maternal height, with a CPS of 28.0% (95% CI, 25.8-30.2%) and SPS of 31.6% (95% CI, 29.5-33.8%). SPS correlated better than CPS with other population-level measures of child health. CONCLUSION: Our study suggests that CPS is sensitive to adjustment for maternal height. Maternal height, while a strong predictor of child stunting, is not amenable to policy interventions. We showed the plausibility of SPS in capturing current exposures to undernutrition and infections in children.

Maternal Grandmothers' Household Residency, Children's Growth, and Body Composition Are Not Related in Urban Maya Families from Yucatan.

This study analyzes the influence of grandmothers' household residency on the presence of low height-for-age and excessive fat (FMI = fat mass [kg]/height [m2]), waist circumference, and sum of triceps and subscapular skinfolds in a sample of 247 6- to 8-year-old urban Maya children from Yucatan, Mexico. Between September 2011 and January 2014, we obtained anthropometric and body composition data from children and mothers, as well as socioeconomic characteristics of participants and households. Grandmothers' place of residence was categorized as either in the same household as their grandchildren (n = 71) or in separate households (n = 176). Multiple logistic regression models were used to analyze the association between grandmothers' residency and outcome variables. Models were adjusted for maternal anthropometric characteristics and the following socioeconomic variables: family size, location, maternal education, monthly family income, and household crowding. Models showed that the presence of grandmothers in their grandchildren's households was not associated with any of the outcome variables. In contrast, larger family size, overcrowding in the household, and lower family income predicted low height-for-age in children. Larger family size decreased the risk for being overweight based on the three parameters of body composition. Overcrowding in the household increased the risk for greater skinfolds thickness, while low family income increased the risk for higher fat mass index. The residency of grandmothers in their adult daughters' households is not significantly associated with the outcome variables in this sample of urban Maya families. Instead, maternal anthropometric characteristics and socioeconomic conditions of the family have a greater influence on the overall growth of children.

Severe acute malnutrition morphological patterns in children under five.

Current methods for infant and child nutritional assessment rely on anthropometric measurements, whose implementation faces technical challenges in low- and middle-income countries. Anthropometry is also limited to linear measurements, ignoring important body shape information related to health. This work proposes the use of 2D geometric morphometric techniques applied to a sample of Senegalese participants aged 6-59 months with an optimal nutritional condition or with severe acute malnutrition to address morphometric variations due to nutritional status. Significant differences in shape and size body changes were described according to nutritional status, resulting age, sex and allometric effect crucial factors to establish nutritional morphological patterns. The constructed discriminant functions exhibited the best classification rates in the left arm. A landmark-based template registering body shape could be useful to both assess acute malnutrition and better understand the morphological patterns that nutritional status promotes in children during their first 5 years of growth and development.

Catch-up growth is a better indicator of undernutrition than thresholds for stunting.

OBJECTIVE: Stunting (height-for-age < -2 sd) is one of the forms of undernutrition and is frequent among children of low- and middle-income countries. But stunting perse is not a synonym of undernutrition. We investigated association between body height and indicators of energetic undernutrition at three critical thresholds for thinness used in public health: (1) BMI SDS < -2; (2) mid-upper arm circumference divided by height (MUAC (mm) × 10/height (cm) < 1·36) and (3) mean skinfold thickness (SF) < 7 mm and to question the reliability of thresholds as indicators of undernutrition. DESIGN: Cross-sectional study; breakpoint analysis. SETTING: Rural and urban regions of Indonesia and Guatemala - different socio-economic status (SES). PARTICIPANTS: 1716 Indonesian children (6·0-13·2 years) and 3838 Guatemalan children (4·0-18·9 years) with up to 50 % stunted children. RESULTS: When separating the regression of BMI, MUAC or SF, on height into distinguishable segments (breakpoint analysis), we failed to detect relevant associations between height, and BMI, MUAC or SF, even in the thinnest and shortest children. For BMI and SF, the breakpoint analysis either failed to reach statistical significance or distinguished at breakpoints above critical thresholds. For MUAC, the breakpoint analysis yielded negative associations between MUAC/h and height in thin individuals. Only in high SES Guatemalan children, SF and height appeared mildly associated with R2 = 0·017. CONCLUSIONS: Currently used lower thresholds of height-for-age (stunting) do not show relevant associations with anthropometric indicators of energetic undernutrition. We recommend using the catch-up growth spurt during early re-feeding instead as immediate and sensitive indicator of past undernourishment. We discuss the primacy of education and social-economic-political-emotional circumstances as responsible factors for stunting.

The timing of adrenarche in Maya girls, Merida, Mexico.

BACKGROUND: Adrenarche involves maturation of the hypothalamic-pituitary-adrenal axis and increased production of dehydroepiandrosterone and its sulfate ester, dehydroepiandrosterone-sulfate (DHEA-S). It occurs at ages 6 to 8 in industrialized populations, marking the transition from childhood to juvenility and cognitive development at middle childhood. Studies in subsistence level populations indicate a later age (8-9) for adrenarche, but only two such studies currently exist for comparison. AIMS: To investigate adrenarcheal age among Maya girls and its association with body composition and dietary variables. We hypothesized adrenarche would occur earlier given the current dual burden of nutrition in Mexico. MATERIALS AND METHODS: 25 Maya girls aged 7 to 9 from Merida, Mexico using ELISAs to measure salivary DHEA-S, standard anthropometry for height, weight, and skinfolds, bioelectrical impedance for body composition variables, as well as a food frequency questionnaire for dietary information. RESULTS: Our hypothesis was rejected-adrenarche occurred close to 9 years. While no measures of body composition were significantly associated with adrenarcheal status, girls eating meat and dairy products more frequently had significantly higher DHEA-S levels. DISCUSSION: Like other populations living in ecologically challenging environments, adrenarche occurred relatively late among Maya girls. Adrenarche has been linked to measures of body composition, particularly, the adiposity or body mass index rebound, but no relevant anthropometric measures were associated, possibly because of the small sample. CONCLUSION: Further studies are required to illuminate how adrenarcheal variation relates to developmental plasticity, body composition, pubertal progression, and animal product consumption in other transitional populations.

Differences and secular trends in childhood IQ trajectories in Guatemala City.

This study documents differences in childhood IQ trajectories of Guatemala City children, aged 6-15 years and born 1961-1993, according to school attended, height-for-age Z-scores (HAZ) and over time (Flynn effect). IQ data come from the Universidad del Valle de Guatemala Longitudinal Study of Child and Adolescent Development. IQ was measured using standardised tests from the Otis-Lennon Mental Ability Test-series. A multilevel model was developed to describe 60,986 IQ observations (level 1), in 22,724 children (level 2), in five schools representing students of different socioeconomic status (SES) (level 3). Average IQ trajectories differed by school. The difference in average IQ at age 11 years between the students of high and low SES schools was 28.7 points. A one-unit increase in HAZ was associated with a 1.42 (0.72, 2.11) unit higher IQ if HAZ was <0, this association was stronger in public compared to private schools. Conversely, one unit increase in HAZ was only associated with a 0.3 (0.001, 0.5) unit higher IQ if HAZ was ≥0. With each birth year increase, IQ at age 11 years increased by 0.14 (95% CI 0.12, 0.16) units, although this Flynn effect attenuated slightly across adolescence. We found no evidence of secular change in the inequality in IQ trajectories (according to school or HAZ). Shorter children from disadvantaged schools in Guatemala City have lower IQ than their taller and wealthier peers, possibly reflecting the damaging effects of poor early life environments both for linear growth and cognitive development.

Association of anthropometric indices of nutritional status with growth in height among Limboo children of Sikkim, India.

Aim: Influence of nutrition in human growth failure, especially stunting, is a well-accepted idea. The present study assesses the influence of nutrition and non-nutritional factors on height growth in a short stature population. Material and methods: The present study was conducted among the children and adolescents of Sikkim, India. The sample size was 538 (boys and girls) of age 2-18 years. The anthropometric indices mid upper arm circumference-for-age Z-scores (MUACZ) and BMI-for-age Z-scores (BAZ) were utilised as proxy of nutritional status and growth was assessed using height-for-age Z-scores (HAZ). Associations were assessed using correlation, St. Nicolas house analysis (SNHA), principal component analysis (PCA) and regression. Results: Nutritional status of the participating children and adolescents as assessed by MUACZ and BAZ were largely normal. Despite variation in HAZ from -4 to +2 there was no influence of the nutritional indices on height. Further, there was clear lack of association between HAZ and socio-economic variables in the present study. Conclusion: The findings of the present study suggest nutrition is not the primary regulator of human growth. The possible influence of community effects on height is discussed.

Plasticity of human growth - a systematic review on psychosocial factors influencing growth.

Background: This systematic review aimed at collecting, analyzing and summarizing scientific studies focusing on psychosocial factors that influence linear growth among humans. Methods: The online database "PubMed" was used in order to acquire suitable scientific studies. These studies were evaluated based on clearly defined criteria that determine whether a study was to be excluded or included in the literature review. In the end, a total sum of 36 studies remained, which were carefully analyzed and used to generate an overview of the association between psychosocial factors and linear growth. Results: In the 36 reviewed studies, different social and psychological factors, such as socioeconomic status, parental education or emotional deprivation were set in relation to physical growth among humans. The studies were listed and summarized, depending on the investigated psychosocial factor. A clear association between psychosocial factors and growth could be observed in most of the reviewed studies. Discussion: Based on the results of the reviewed studies it could be concluded that the regulation of linear growth is also subject to different psychosocial factors. The way in which the developing human and the specific social environment interact seemed to have a major impact on linear growth. Status-specific stress was discussed as one possible explanation for the regulating mechanism of human linear growth.

Low birthweight prevalence among Spanish women during the economic crisis: differences by parity.

Previous studies have demonstrated a negative, significant impact on birthweight associated with the current economic crisis in Spain, which has also been reported for other European countries. Effects by parity are not known. Our aim is to compare the trends in low birthweight (LBW) by parity in Spain from 1996 to 2016. Using the National Vital Statistics data, joinpoint regression analysis was used to identify the time periods of significant changes in the prevalence of LBW by parity. Adjusted relative risk (RR) of LBW by year of birth was calculated in order to confirm that the time trend differences in LBW by parity were independent of possible confounders. The prevalence of LBW among live births to primiparous increased from 5.12% to 6.87% in 2008 and then stabilised at maximum values, while among live births to multiparous LBW increased from 3.96% to a maximum of 5.20% and then significantly reduced. Trends in adjusted RR of LBW by parity confirm that primiparous and multiparous were affected differently by the economic crisis. Older, nulliparous women may have felt more biosocial pressure to reproduce during the economic crisis, compared to women who were already mothers. This biosocial pressure may have increased the risks for LBW.

Birth weight, birth order, and age at first solid food introduction influence child growth and body composition in 6- to 8-year-old Maya children: The importance of the first 1000 days of life.

OBJECTIVES: To analyze the relationship of birth weight, birth order, breastfeeding duration, and age of introduction of solid foods with height, fat mass, and fat-free mass in a sample of Maya children when aged 6 to 8 years old. METHODS: We collected data on anthropometry, body composition, children's birth weight, birth order, early feeding practices, and household socioeconomic characteristics in a sample of 260 Maya children aged 6 to 8 years living in Merida and Motul, two cities in Yucatan, Mexico. Multiple regression models were performed to identify variables associated with height-for-age (HAZ), fat mass index (FMI), and fat-free mass index (FFMI). The predictors included in the models were birth weight (kg), birth order, duration of breastfeeding (months), age at introduction of solid foods (months), maternal age (years), and height (cm). Models were adjusted for the influence of children's age and sex, maternal educational level, and household overcrowding. RESULTS: HAZ was positively associated with child birthweight and maternal height and age, but inversely associated with birth order and age of introduction of solid foods. FMI was positively associated with birth weight, maternal age, and height, and negatively associated with birth order. FFMI was positively associated with maternal age and birth weight. CONCLUSIONS: These results are evidence of the importance of the first 1000 days of life for the growth and body composition of Maya children and contributed to understand the development of nutritional dual burden in this population.