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.

Meta-evaluation of a whole systems programme, ActEarly: A study protocol.

INTRODUCTION: Living in an area with high levels of child poverty predisposes children to poorer mental and physical health. ActEarly is a 5-year research programme that comprises a large number of interventions (>20) with citizen science and co-production embedded. It aims to improve the health and well-being of children and families living in two areas of the UK with high levels of deprivation; Bradford in West Yorkshire, and the London Borough of Tower Hamlets. This protocol outlines the meta-evaluation (an evaluation of evaluations) of the ActEarly programme from a systems perspective, where individual interventions are viewed as events in the wider policy system across the two geographical areas. It includes investigating the programme's impact on early life health and well-being outcomes, interdisciplinary prevention research collaboration and capacity building, and local and national decision making. METHODS: The ActEarly meta-evaluation will follow and adapt the five iterative stages of the 'Evaluation of Programmes in Complex Adaptive Systems' (ENCOMPASS) framework for evaluation of public health programmes in complex adaptive systems. Theory-based and mixed-methods approaches will be used to investigate the fidelity of the ActEarly research programme, and whether, why and how ActEarly contributes to changes in the policy system, and whether alternative explanations can be ruled out. Ripple effects and systems mapping will be used to explore the relationships between interventions and their outcomes, and the degree to which the ActEarly programme encouraged interdisciplinary and prevention research collaboration as intended. A computer simulation model ("LifeSim") will also be used to evaluate the scale of the potential long-term benefits of cross-sectoral action to tackle the financial, educational and health disadvantages faced by children in Bradford and Tower Hamlets. Together, these approaches will be used to evaluate ActEarly's dynamic programme outputs at different system levels and measure the programme's system changes on early life health and well-being. DISCUSSION: This meta-evaluation protocol presents our plans for using and adapting the ENCOMPASS framework to evaluate the system-wide impact of the early life health and well-being programme, ActEarly. Due to the collaborative and non-linear nature of the work, we reserve the option to change and query some of our evaluation choices based on the feedback we receive from stakeholders to ensure that our evaluation remains relevant and fit for purpose.

Development of Public Health Core Outcome Sets for Systems-Wide Promotion of Early Life Health and Wellbeing.

We aimed to develop a core outcome set (COS) for systems-wide public health interventions seeking to promote early life health and wellbeing. Research was embedded within the existing systems-based intervention research programme 'ActEarly', located in two different areas with high rates of child poverty, Bradford (West Yorkshire) and the Borough of Tower Hamlets (London). 168 potential outcomes were derived from five local government outcome frameworks, a community-led survey and an ActEarly consortium workshop. Two rounds of a Delphi study (Round 1: 37 participants; Round 2: 56 participants) reduced the number of outcomes to 64. 199 members of the community then took part in consultations across ActEarly sites, resulting in a final COS for systems-based public health interventions of 40 outcomes. These were grouped into the domains of: Development & education (N = 6); Physical health & health behaviors (N = 6); Mental health (N = 5); Social environment (N = 4); Physical environment (N = 7); and Poverty & inequality (N = 7). This process has led to a COS with outcomes prioritized from the perspectives of local communities. It provides the means to increase standardization and guide the selection of outcome measures for systems-based evaluation of public health programmes and supports evaluation of individual interventions within system change approaches.

Growth delay: an alternative measure of population health based on child height distributions.

BACKGROUND: Indicators of child height, such as mean height-for-age Z-scores (HAZ), height-for-age difference (HAD) and stunting prevalence, do not account for differences in population-average bone developmental stage. AIM: Propose a measure of child height that conveys the dependency of linear growth on stage rather than chronological age. SUBJECTS AND METHODS: Using Demographic and Health Surveys (2000-2018; 64 countries), we generated: (1) predicted HAZ at specific ages (HAZ regressed on age); (2) height-age (age at which mean height matches the WHO Growth Standards median); (3) Growth delay (GD), the difference between chronological age and height-age; (4) HAD; and (5) stunting prevalence. Metrics were compared based on secular trends within countries and age-related trajectories within surveys. RESULTS: In the most recent surveys (N = 64), GDs ranged from 1.9 to 19.1 months at 60 months chronological age. Cross-sectionally, HAZ, HAD and GD were perfectly correlated, and showed similar secular trends. However, age-related trajectories differed across metrics. Accumulating GD with age demonstrated growth faltering as slower than expected growth for children of the same height-age. Resumption of growth at the median for height-age was rarely observed. CONCLUSION: GD is a population-level measure of child health that reflects the role of delayed skeletal development in linear growth faltering.

Early childhood weight gain: Latent patterns and body composition outcomes.

BACKGROUND: Despite early childhood weight gain being a key indicator of obesity risk, we do not have a good understanding of the different patterns that exist. OBJECTIVES: To identify and characterise distinct groups of children displaying similar early-life weight trajectories. METHODS: A growth mixture model captured heterogeneity in weight trajectories between 0 and 60 months in 1390 children in the Avon Longitudinal Study of Parents and Children. Differences between the classes in characteristics and body size/composition at 9 years were investigated. RESULTS: The best model had five classes. The "Normal" (45%) and "Normal after initial catch-down" (24%) classes were close to the 50th centile of a growth standard between 24 and 60 months. The "High-decreasing" (21%) and "Stable-high" (7%) classes peaked at the ~91st centile at 12-18 months, but while the former declined to the ~75th centile and comprised constitutionally big children, the latter did not. The "Rapidly increasing" (3%) class gained weight from below the 50th centile at 4 months to above the 91st centile at 60 months. By 9 years, their mean body mass index (BMI) placed them at the 98th centile. This class was characterised by the highest maternal BMI; highest parity; highest levels of gestational hypertension and diabetes; and the lowest socio-economic position. At 9 years, the "Rapidly increasing" class was estimated to have 68.2% (95% confidence interval [CI] 48.3, 88.1) more fat mass than the "Normal" class, but only 14.0% (95% CI 9.1, 18.9) more lean mass. CONCLUSIONS: Criteria used in growth monitoring practice are unlikely to consistently distinguish between the different patterns of weight gain reported here.

Distinct Body Mass Index Trajectories to Young-Adulthood Obesity and Their Different Cardiometabolic Consequences.

[Figure: see text].

How can two biological variables have opposing secular trends, yet be positively related? A demonstration using timing of puberty and adult height.

Timing of puberty and adult height have opposing secular trends yet are positively associated in individuals. We demonstrate this using data from a single sample and discuss possible statistical and epidemiological reasons behind it. The sample comprised 365 females from Fels Longitudinal Study born 1929-1992. We used Super-Imposition by Translation and Rotation (SITAR) to estimate individual age at peak height velocity (PHV) and PHV from serial height data (8149 observations between 5 and 24 years). General linear regression was used to investigate the association between height and age at PHV, and secular trends in height, age at PHV and PHV. Although adult height increased 0.42 (95% CI: 0.08, 0.77) cm per decade, and age at PHV decreased 1.14 (-3.74, 1.45) weeks per decade, adult height increased by 2.44 (1.78, 3.10) cm per year higher age at PHV. We found tentative evidence of the positive association between age at PHV and adult height strengthened 0.25 (-0.09, 0.59) cm each decade. Secular trends in related variables may differ if the between-individual and between-cohort associations are different. To understand if a secular trend in one variable has contributed to a trend in another, each needs to be modelled over time, together with the changing association between them.

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.

Four decades of socio-economic inequality and secular change in the physical growth of Guatemalans.

OBJECTIVE: To investigate changes in socio-economic inequalities in growth in height, weight, BMI and grip strength in children born during 1955-1993 in Guatemala, a period of marked socio-economic-political change. DESIGN: We modelled longitudinal data on height, weight, BMI and hand grip strength using Super-Imposition by Translation and Rotation (SITAR). Internal Z-scores summarising growth size, timing and intensity (peak growth velocity, e.g. cm/year) were created to investigate inequalities by socio-economic position (SEP; measured by school attended). Interactions of SEP with date of birth were investigated to capture secular changes in inequalities. SETTING: Urban and peri-urban schools in the region of Guatemala City, Guatemala. PARTICIPANTS: Participants were 40 484 children and adolescents aged 3-19 years of Ladino and Maya ancestry (nobservations 157 067). RESULTS: The difference in height (SITAR size) between lowest and highest SEP decreased from -2·0 (95 % CI -2·2, -1·9) sd to -1·4 (95 % CI -1·5, -1·3) sd in males, and from -2·0 (95 % CI -2·1, -1·9) sd to -1·2 (95 % CI -1·3, -1·2) sd in females over the study period. Inequalities also reduced for weight, BMI and grip strength, due to greater secular increases in lowest-SEP groups. The puberty period was earlier and shorter in higher-SEP individuals (earlier SITAR timing and higher SITAR intensity). All SEP groups showed increases in BMI intensity over time. CONCLUSIONS: Inequality narrowed between the 1960s and 1990s. The lowest-SEP groups were still >1 sd shorter than the highest. Risks remain for reduced human capital and poorer population health for urban Guatemalans.

Life course associations of height, weight, fatness, grip strength, and all-cause mortality for high socioeconomic status Guatemalans.

OBJECTIVES: The objective of this study was to investigate the association between physical growth in preadult life with five outcomes at ages 64 to 76: weight, body mass index (BMI), estimated body fat percentage, hand grip strength, and mortality. METHODS: Super-imposition by translation and rotation (SITAR) growth curves of 40 484 Guatemalan individuals aged 3 to 19 years were modeled for the parameters of size, timing and intensity (peak growth velocity, eg, cm/year) of height, weight, BMI, and grip strength. Associations between the SITAR parameters and old age outcomes were tested using linear and binary logistic regression for a follow-up sample of high socioeconomic status (SES) Guatemalans, of whom 50 were aged 64 to 76 years at re-measurement and 45 died prior to the year 2017. RESULTS: SITAR models explained 69% to 98% of the variance in each outcome, with height the most precise. Individuals in the follow-up sample who had a higher BMI before the age of 20 years had higher estimated body fat (B = 1.4 CI -0.02-2.8) and BMI (B = 1.2, CI 0.2-2.2) at the ages of 64 to 76 years. Those who grew slower in height but faster in weight and BMI before the age of 20 years had higher BMI and body fat later in life. CONCLUSIONS: These findings highlight the importance of a life course perspective on health and mortality risk. Childhood exposures leading to variation in preadult growth may be key to better understanding health and mortality risks in old age.

Instability in longitudinal childhood IQ scores of Guatemalan high SES individuals born between 1941-1953.

Childhood IQ has been used to predict later life outcomes across disciplines in epidemiology, education, and psychology. Most often only a single childhood IQ test is available or is used for these purposes in the belief that IQ is stable across the life course. The primary aim of this study was to examine the longitudinal stability of individuals' IQ test scores derived from school-age tests. The secondary aim was to investigate the association of the pre-adult scores with later life intelligence scores. The longitudinal pre-adult IQ scores of 42 high socioeconomic status Guatemalans born 1941-1953 were analysed and showed low stability of longitudinal test scores. Fluctuations of >1SD were found for 59.5% of the sample. The same participants, aged 64-76 years, were re-assessed and average pre-adult IQ explained 12% of variance in the older age intelligence score. The reasons behind the longitudinal instability in test scores reported in this study remains unknown but the results suggest single point measurements of intelligence before adulthood should be regarded with some caution.

Smaller long bone cross-sectional size in people who died of tuberculosis: Insights on frailty factors from a 19th and early 20th century Finnish population.

There is little research on how individuals suffering from tuberculosis may differ from those not infected in terms of overall skeletal morphology. Tuberculosis was endemic in 19th and early 20th century Finland making documented skeletal collections of Finns ideal to study effects of the disease on bone. The present study compares long bone cross-sectional total area between individuals who died of tuberculosis and those with another recorded cause of death in a Finnish sample. Adult male individuals (N = 105) were selected for analysis. Complete humeri (N = 56), femora (N = 66) and tibiae (N = 64) were 3D scanned using a laser scanner and total cross-sectional areas calculated with AsciiSection software. Individuals who died of tuberculosis (N = 24, 15 humeri, 14 femora, 13 tibiae) had, when standardized for body size, significantly smaller total cross-sectional femoral and humeral, but not tibial, areas. The mechanisms behind the observed relationship may reflect a combination of biological 'frailty' in terms of susceptibility to infection, reduced childhood activity and/or vitamin D deficiency, which possibly influenced both subperiosteal development during adolescence and, later, susceptibility to contracting and dying of TB. Due to the relatively small sample future studies are needed to further investigate the relationship between TB and bone cross-sectional size.