Socio-economic and dietary influences on leg length and trunk length in childhood: a reanalysis of the Carnegie (Boyd Orr) survey of diet and health in prewar Britain (1937-39)

Variation in body size and weight status among Hindu and Muslim Indian males born in the 1890s through the 1950s

Hindus and Muslims represent the two largest religions in India, and also differ in nutritional status, health-related habits and standard of living associated with economic disparities. In this context, the present study considered estimated secular changes in body size, proportions, and weight status among Hindu and Muslim Indian men. The data are from anthropological surveys in the 1970s which included measurements of height, weight and sitting height of 43,950 males 18-84 years (birth years 1891-1957). Leg length was estimated; the BMI and sitting height/height ratio were calculated. Heights of men 35 + years were adjusted for estimated height loss with age. Weight status was also classified relative to WHO criteria for the BMI. Anthropometric characteristics of the two groups were compared with MANCOVA with age and geographic region as covariates. Linear regression of height on year of birth was also used to estimate secular change in each group. Heights, weights, and BMIs tended to be, on average, greater among Muslim than Hindu men at most ages, while distributions by weight status between groups were negligible. Sitting height was greater among Muslim men but estimated leg length did not differ between groups; the sitting height/height ratio thus suggested proportionally shorter legs among Muslim men. Results of the regression analyses indicated negligible differences in secular change between groups across the total span of birth years but indicated a decline in adjusted heights of men in both groups born between 1891 through 1930s and little secular change among those born in the 1930s through 1957. The variation in heights, weights and BMIs between Muslim and Hindu men at most ages suggested variation in socio-economic status and dietary habits between the groups, whereas the negligible estimated secular changes in height between groups likely reflected economic, social, and nutritional conditions during the interval of British rule and the transition to independence.

Reconsidering the developmental origins of adult disease paradigm: The 'metabolic coordination of childbirth' hypothesis

In uncomplicated pregnancies, birthweight is inversely associated with adult non-communicable disease (NCD) risk. One proposed mechanism is maternal malnutrition during pregnancy. Another explanation is that shared genes link birthweight with NCDs. Both hypotheses are supported, but evolutionary perspectives address only the environmental pathway. We propose that genetic and environmental associations of birthweight with NCD risk reflect coordinated regulatory systems between mother and foetus, that evolved to reduce risks of obstructed labour. First, the foetus must tailor its growth to maternal metabolic signals, as it cannot predict the size of the birth canal from its own genome. Second, we predict that maternal alleles that promote placental nutrient supply have been selected to constrain foetal growth and gestation length when fetally expressed. Conversely, maternal alleles that increase birth canal size have been selected to promote foetal growth and gestation when fetally expressed. Evidence supports these hypotheses. These regulatory mechanisms may have undergone powerful selection as hominin neonates evolved larger size and encephalisation, since every mother is at risk of gestating a baby excessively for her pelvis. Our perspective can explain the inverse association of birthweight with NCD risk across most of the birthweight range: any constraint of birthweight, through plastic or genetic mechanisms, may reduce the capacity for homeostasis and increase NCD susceptibility. However, maternal obesity and diabetes can overwhelm this coordination system, challenging vaginal delivery while increasing offspring NCD risk. We argue that selection on viable vaginal delivery played an over-arching role in shaping the association of birthweight with NCD risk.

Early life drought predicts components of adult body size in wild female baboons

OBJECTIVES

In many taxa, adverse early-life environments are associated with reduced growth and smaller body size in adulthood. However, in wild primates, we know very little about whether, where, and to what degree trajectories are influenced by early adversity, or which types of early adversity matter most. Here, we use parallel-laser photogrammetry to assess inter-individual predictors of three measures of body size (leg length, forearm length, and shoulder-rump length) in a population of wild female baboons studied since birth.

MATERIALS AND METHODS

Using >2000 photogrammetric measurements of 127 females, we present a cross-sectional growth curve of wild female baboons (Papio cynocephalus) from juvenescence through adulthood. We then test whether females exposed to several important sources of early-life adversity-drought, maternal loss, low maternal rank, or a cumulative measure of adversity-were smaller for their age than females who experienced less adversity. Using the "animal model," we also test whether body size is heritable in this study population.

RESULTS

Prolonged early-life drought predicted shorter limbs but not shorter torsos (i.e., shoulder-rump lengths). Our other measures of early-life adversity did not predict variation in body size. Heritability estimates for body size measures were 36%-67%. Maternal effects accounted for 13%-17% of the variance in leg and forearm length, but no variance in torso length.

DISCUSSION

Our results suggest that baboon limbs, but not torsos, grow plastically in response to maternal effects and energetic early-life stress. Our results also reveal considerable heritability for all three body size measures in this study population.

Social and early life determinants of survival from cradle to grave: A case study in wild baboons

Field studies of natural mammal populations present powerful opportunities to investigate the determinants of health and aging using fine-grained observations of known individuals across the life course. Here, we synthesize five decades of findings from one such study: the wild baboons of the Amboseli ecosystem in Kenya. First, we discuss the profound associations between early life adversity, adult social conditions, and key aging outcomes in this population, especially survival. Second, we review potential mediators of the relationship between early life adversity and survival in our population. Notably, our tests of two leading candidate mediators-social isolation and glucocorticoid levels-fail to identify a single, strong mediator of early life effects on adult survival. Instead, early adversity, social isolation, and glucocorticoids are independently linked to adult lifespans, suggesting considerable scope for mitigating the negative consequences of early life adversity. Third, we review our work on the evolutionary rationale for early life effects on mortality, which currently argues against clear predictive adaptive responses. Finally, we end by highlighting major themes emerging from the study of sociality, development, and aging in the Amboseli baboons, as well as important open questions for future work.

Height, social position and coronary heart disease incidence: the contribution of genetic and environmental factors

BACKGROUND

The associations between height, socioeconomic position (SEP) and coronary heart disease (CHD) incidence are well established, but the contribution of genetic factors to these associations is still poorly understood. We used a polygenic score (PGS) for height to shed light on these associations.

METHODS

Finnish population-based health surveys in 1992-2011 (response rates 65-93%) were linked to population registers providing information on SEP and CHD incidence up to 2019. The participants (N=29 996; 54% women) were aged 25-75 at baseline, and there were 1767 CHD incident cases (32% in women) during 472 973 person years of follow-up. PGS-height was calculated based on 33 938 single-nucleotide polymorphisms, and residual height was defined as the residual of height after adjusting for PGS-height in a linear regression model. HRs of CHD incidence were calculated using Cox regression.

RESULTS

PGS-height and residual height showed clear gradients for education, social class and income, with a larger association for residual height. Residual height also showed larger associations with CHD incidence (HRs per 1 SD 0.94 in men and 0.87 in women) than PGS-height (HRs per 1 SD 0.99 and 0.97, respectively). Only a small proportion of the associations between SEP and CHD incidence was statistically explained by the height indicators (6% or less).

CONCLUSIONS

Residual height associations with SEP and CHD incidence were larger than for PGS-height. This supports the role of material and social living conditions in childhood as contributing factors to the association of height with both SEP and CHD risk.

Calibration of Bioelectrical Impedance Analysis Against Deuterium Dilution for Body Composition Assessment in Stunted Ugandan Children

BACKGROUND

BIA represents an important tool in body composition (BC) assessment, especially in low-income settings in which simple and affordable options are preferred. There is a particular need to measure BC in stunted children, in which cases population-specific BIA estimating equations are lacking.

OBJECTIVES

We calibrated an equation to estimate body composition from BIA using deuterium dilution (²H) as the criterion method in stunted children.

METHODS

We measured BC with ²H and performed BIA in stunted Ugandan children (n = 50). Multiple linear regression models were constructed to predict ²H-derived FFM from BIA-derived whole-body impedance and other relevant predictors. Model performance was expressed as adjusted R² and RMSE. Prediction errors were also calculated.

RESULTS

Participants were aged 16-59 mo, of whom 46% were girls, and their median (IQR) height-for-age z-score (HAZ) was -2.58 (-2.92 to -2.37) according to the WHO growth standards. Impedance index (height²/impedance measured at 50 kHz) alone explained 89.2% variation in FFM and had an RMSE of 583 g (precision error 6.5%). The final model contained age, sex, impedance index, and height-for-age z-score as predictors and explained 94.5% variation in FFM with an RMSE of 402 g (precision error 4.5%).

CONCLUSIONS

We present a BIA calibration equation for a group of stunted children with a relatively low prediction error. This may help evaluate the efficacy of nutritional supplementation in large-scale trials in the same population. J Nutr 20XX;xxx:xx.

Upper arm length and knee height are associated with diabetes in the middle-aged and elderly: evidence from the China Health and Retirement Longitudinal Study

OBJECTIVE

To determine if limb lengths, as markers of early life environment, are associated with the risk of diabetes in China.

DESIGN

We performed a cohort analysis using data from the China Health and Retirement Longitudinal Study (CHARLS), and multivariable-adjusted Cox proportional hazard regression models were used to examine the associations between baseline limb lengths and subsequent risk of diabetes.

SETTING

The CHARLS, 2011-2018.

PARTICIPANTS

The study confined the eligible subject to 10 711 adults aged over 45 years from the CHARLS.

RESULTS

During a mean follow-up period of 6·13 years, 1358 cases of incident diabetes were detected. When controlling for potential covariates, upper arm length was inversely related to diabetes (hazard ratio (HR) 0·95, 95 % CI (0·91, 0·99), P = 0·028), and for every 1-cm difference in knee height, the risk of diabetes decreased by about 4 % (HR 0·96, 95 % CI (0·93, 0·99), P = 0·023). The association between upper arm length and diabetes was only significant among females while the association between knee height and diabetes was only significant among males. In analyses stratified by BMI, significant associations between upper arm length/knee height and diabetes only existed among those who were underweight (HR 0·91, 95 % CI (0·83, 1·00), P = 0·049, HR 0·92, 95 % CI (0·86, 0·99), P = 0·031).

CONCLUSIONS

Inverse associations were observed between upper arm length, knee height and the risk for diabetes development in a large Asian population, suggesting early life environment, especially infant nutritional status, may play an important role in the determination of future diabetes risk.

The effect of different socio-economic and working conditions on body size and proportions: A case study on adults from Samsun, Turkey

Conditions in the early stages of life shape body size and proportions. This study includes individuals who came from different socio-economic conditions and worked in physically demanding jobs in childhood. By determining the body sizes of these individuals and evaluating the proportional relationships between several groups, the goal was to understand the effect levels of socio-economic levels and working conditions on the body. For this purpose, an anthropometric study was conducted on 623 males and females between the ages of 20 and 45 living in Samsun, Turkey. The study sample consisted of four different groups. It was divided into two main groups of high and low socio-economic level, and the low socio-economic group was divided into two subgroups of heavy-worker and nonheavy-worker. The results demonstrated that socio-economic differences in the size and proportions of the individuals were statistically significant (p<0.05). The high socio-economic group had the highest values in all measures. External factors affected the lower limbs more than the upper limbs. The measurement most affected by these factors was leg length. Longer legs characterized the high socio-economic group, while longer arms characterized both low socio-economic groups. The relative differences observed can be said to derive from the distal limbs. This finding was valid for both sexes. The average values were close to each other in the low socio-economic group, for which the aim was to comprehend the effects of heavy working conditions. However, differences in proportional relationships were more significant. In this context, it was seen that heavy labour also affected growth, in addition to the well-known factors encountered during the growth period, such as nutrition, health, and illness. The observed changes were more significant in males than in females. Thus, it can be said that males were more affected by physiological and physical conditions.

A quantitative synthesis study on body mass index and associated factors among adult men and women in Switzerland

Excess weight is caused by multiple factors and has increased sharply in Switzerland since the 1990s. Its consequences represent a major challenge for Switzerland, both in terms of health and the economy. Until now, there has been no cross-dataset overview study on excess weight in adults in Switzerland. Therefore, our aim was to conduct the first synthesis on excess weight in Switzerland. We included all existing nationwide Swiss studies (eight total), which included information on body mass index (BMI). Mixed multinomial logistic regression analyses were performed to assess the associations between different socio-demographic, lifestyle cofactors and the World Health Organization (WHO) categories for BMI. Along with lifestyle factors, socio-demographic factors were among the strongest determinants of BMI. In addition, self-rated health status was significantly lower for underweight, pre-obese and obese men and women than for normal weight persons. The present study is the first to synthesise all nationwide evidence on the importance of several socio-demographic and lifestyle factors as risk factors for excess weight. In particular, the highlighted importance of lifestyle factors for excess weight opens up the opportunity for further public health interventions.

Implications of leg length for metabolic health and fitness

Background and objectives

Several studies have linked longer legs with favorable adult metabolic health outcomes and greater offspring birth weight. A recent Mendelian randomization study suggested a causal link between height and cardiometabolic risk; however, the underlying reasons remain poorly understood.

Methodology

Using a cross-sectional design, we tested in a convenience sample of 70 healthy young women whether birth weight and tibia length as markers of early-life conditions associated more strongly with metabolically beneficial traits like organ size and skeletal muscle mass (SMM) than a statistically derived height-residual variable indexing later, more canalized growth.

Results

Consistent with the 'developmental origins of health and disease' hypothesis, we found relatively strong associations of tibia length-but not birth weight-with adult organ size, brain size, SMM and resting energy expenditure measured by magnetic resonance imaging (MRI), dual-energy X-ray absorptiometry and indirect calorimetry, respectively.

Conclusions and implications

Building on prior work, these results suggest that leg length is a sensitive marker of traits directly impacting metabolic and reproductive health. Alongside findings in the same sample relating tibia length and height-residual to MRI-measured pelvic dimensions, we suggest there may exist a degree of coordination in the development of long bone, lean mass and pelvic traits, possibly centered on early, pre-pubertal growth periods. Such phenotypic coordination has important implications for fitness, serving to benefit both adult health and the health of offspring in subsequent generations.

The role of body height as a co-factor of excess weight in Switzerland

Object

Excess weight (Body Mass Index [BMI] ≥25.0 kg/m²) is a major health issue worldwide, including in Switzerland. For high‐income countries, little attention has been paid to body height in context of excess weight. The aim of this study is to assess the importance of body height as a co‐factor for excess weight in multiple large nationwide data sets.

Data and methods

In this comparative study, we included the largest nationwide and population‐based studies in the fields of public health, nutrition and economics for Switzerland, as well as data of the medical examination during conscription for the Swiss Armed Forces, which contained information on BMI and, if possible, waist‐to‐height‐ratio (WHtR) and waist‐to‐hip‐ratio (WHR).

Results

The multinomial logistic regressions show that the probability of belonging to the excess weight category (BMI ≥25.0 kg/m²) decreased with increasing height in both sexes inall contemporary data sets. This negative association was shown to be constant, only among conscripts measured in the 1870s the association was positive, when increasing height was associated with a higher BMI. The negative association not only emerge in BMI, but also in WHtR and WHR.

Conclusion

Our results emphasize the importance of body height as a co‐factor of excess weight, suggesting a clear negative association between height and BMI, WHtR and WHR. Evidence indicates that both early‐life environmental exposures and alleles associated with height may contribute to these associations. This knowledge could serve as further starting points for prevention programs in the field of public health.

Evolution of Lactase Persistence: Turbo-Charging Adaptation in Growth Under the Selective Pressure of Maternal Mortality?

The emergence of the capacity to digest milk in some populations represents a landmark in human evolution, linking genetic change with a component of niche construction, namely dairying. Alleles promoting continued activity of the enzyme lactase through the life-course (lactase persistence) evolved in several global regions within the last 7,000 years. In some European regions, these alleles underwent rapid selection and must have profoundly affected fertility or mortality. Elsewhere, alleles spread more locally. However, the functional benefits underlying the rapid spread of lactase persistence remain unclear. Here, we set out the hypothesis that lactase persistence promoted skeletal growth, thereby offering a generic rapid solution to childbirth complications arising from exposure to ecological change, or to new environments through migration. Since reduced maternal growth and greater neonatal size both increase the risk of obstructed labour, any ecological exposure impacting these traits may increase maternal mortality risk. Over many generations, maternal skeletal dimensions could adapt to new ecological conditions through genetic change. However, this adaptive strategy would fail if ecological change was rapid, including through migration into new niches. We propose that the combination of consuming milk and lactase persistence could have reduced maternal mortality by promoting growth of the pelvis after weaning, while high calcium intake would reduce risk of pelvic deformities. Our conceptual framework provides locally relevant hypotheses to explain selection for lactase persistence in different global regions. For any given diet and individual genotype, the combination of lactase persistence and milk consumption would divert more energy to skeletal growth, either increasing pelvic dimensions or buffering them from worsening ecological conditions. The emergence of lactase persistence among dairying populations could have helped early European farmers adapt rapidly to northern latitudes, East African pastoralists adapt to sudden climate shifts to drier environments, and Near Eastern populations counteract secular declines in height associated with early agriculture. In each case, we assume that lactase persistence accelerated the timescale over which maternal skeletal dimensions could change, thus promoting both maternal and offspring survival. Where lactase persistence did not emerge, birth weight was constrained at lower levels, and this contributes to contemporary variability in diabetes risk.

Sex differences in diet and life conditions in a rural Medieval Islamic population from Spain (La Torrecilla, Granada): An isotopic and osteological approach to gender differentiation in al-Andalus

OBJECTIVES

Gender differentiation can influence the diet, physical activity, and health of human populations. Multifaceted approaches are therefore necessary when exploring the biological consequences of gender-related social norms in the past. Here, we explore the links between diet, physiological stress, physical activity, and gender differentiation in the Medieval Islamic population of La Torrecilla (Granada, Spain, 13th-15th century AD), by analyzing stable isotope patterns, stature, and long bone diaphyseal measurements.

MATERIALS AND METHODS

The sample includes 96 individuals (48 females, 48 males) classified as young and middle adults (20-34 and 35-50 years of age respectively). Diet was reconstructed through the analysis of δ¹³ C and δ¹⁵ N. Stature, humeral and femoral diaphyseal shape and product of diaphyseal diameters served as proxies of physiological stress and physical activity.

RESULTS

Isotopic ratios suggest a substantial dietary contribution of C₄ plants (e.g., sorghum, millet), a variable access to animal proteins, and no differences between the sexes. Sexual dimorphism in stature derives from a markedly low female stature. Long bone diaphyseal properties suggest that men performed various physically stressful activities, whereas women were involved in less physically demanding activities (possibly related to household work).

DISCUSSION

Gender differentiation in La Torrecilla was expressed by a possibly differential parental investment in male versus female offspring and by culturally sanctioned gender differences in the performance of physical tasks. Diet was qualitatively homogenous between the sexes, although we cannot rule out quantitative differences. Our results shed new light on the effects of gender-related social norms on human development and lifestyle.

Inter-relationships between percentage body fat, relative subischial leg length and body mass index among adolescents and adults from the Limbu community of Darjeeling, West Bengal

Leg length in humans is considered to be an indicator of the long-term impact of quality of childhood living conditions and nutritional status. The main objective of this study was to evaluate the magnitude of association of percentage body fat (PBF) with relative subischial leg length (RSLL), adjusting for age, sex and body mass index (BMI), among adolescents and adults in a population of poor socioeconomic background in India. Data were taken from a cross-sectional study conducted in 2010-2014 among the Limbu community of Darjeeling, West Bengal - an indigenous community with poor socioeconomic background, low literacy rate, low income and inadequate living conditions. The study villages were located in the Himalayan and sub-Himalayan regions of Darjeeling. The present study sample comprised 97 adolescents aged 16-19 years (47 boys, 50 girls) and 260 adults aged 20-39 years (135 men, 125 women). Anthropometric measurements of stature/height (cm), weight (kg), sitting height (cm) and skinfold thicknesses (biceps, triceps, subscapular, suprailiac) (mm) were recorded. Derived variables were BMI (kg/m2), subischial leg length (SLL) (cm), RSLL (%), sum of four skinfolds (mm) and PBF (%). Significant sex differences at p<0.05 were observed for all anthropometric characteristics, except for body weight among adolescents and RSLL, subscapular and sum of four skinfolds in adults. The linear regression models adjusting for age and sex showed that RSLL had a negative relationship with PBF (p<0.05) among adolescents and adults. Higher body fat, independent of BMI, was correlated with lower RSLL among both adolescents and adults from the Limbu community, indicating a possible association with poor quality living conditions in childhood. However, this may also have been due to the allometry of total body fat with body proportions - a relatively larger trunk results in more body fat.

Physical Activity Throughout Adolescence and Peak Hip Strength in Young Adults

IMPORTANCE

Peak bone strength, which occurs in early adulthood, is an important marker of the future risk of osteoporosis. It is therefore important to identify modifiable early life factors that are associated with the attainment of peak hip strength.

OBJECTIVE

To investigate the association of time spent in moderate to vigorous-intensity and light-intensity physical activity throughout adolescence with peak hip strength in adulthood.

DESIGN, SETTING, AND PARTICIPANTS

The Avon Longitudinal Study of Parents and Children is a prospective birth cohort study that initially recruited all pregnant women residing within the catchment area of 3 health authorities in southwest England who had an expected delivery date between April 1, 1991, and December 31, 1992. In total, 15 454 eligible pregnant women were enrolled, and 15 589 infants were delivered. Of those, 14 901 infants were alive at age 1 year. The present analysis examined 2569 healthy offspring who had valid physical activity measurements obtained during a clinical assessment for at least 1 age (12, 14, 16, and/or 25 years), with up to 4 repeated accelerometer assessments performed (1 per age-associated clinical visit). Data were analyzed from June 2019 to June 2020.

EXPOSURES

Trajectories of accelerometer-assessed time spent in moderate to vigorous-intensity and light-intensity physical activity at ages 12, 14, 16, and 25 years (measured in minutes per day) were identified using latent trajectory modeling. Moderate to vigorous-intensity and light-intensity physical activity were determined using established thresholds of acceleration counts per minute.

MAIN OUTCOMES AND MEASURES

Femur neck bone mineral density (BMD; measured in g/cm2) at age 25 years assessed by dual-energy radiography absorptiometry scans of the hip.

RESULTS

A total of 2569 participants (1588 female participants [62%]) were included in the analysis. Male participants spent more time in moderate to vigorous-intensity activity at each age and had greater adult femur neck BMD than female participants. For each sex, 3 moderate to vigorous-intensity trajectory subgroups and 3 light-intensity trajectory subgroups were identified. With regard to the moderate to vigorous-intensity trajectories, most male participants (85%) were in the low adolescent subgroup, with only 6% and 9% in the high early-adolescent and high mid-adolescent subgroups, respectively. Moderate to vigorous-intensity trajectories in female participants were divided into low adolescent-low adult (73%), low adolescent-high adult (8%), and high adolescent (19%) subgroups. Light-intensity physical activity trajectories were classified into low nonlinear, moderate decreasing, and high decreasing subgroups for both sexes. Femur neck BMD in male participants was greater in the high early-adolescent subgroup (0.38 g/cm2; 95% CI, 0.11-0.66 g/cm2) and the high mid-adolescent subgroup (0.33 g/cm2; 95% CI, 0.07-0.60 g/cm2) compared with the low adolescent (reference) subgroup. Femur neck BMD in female participants was greater in the high adolescent subgroup (0.28 g/cm2; 95% CI, 0.15-0.41 g/cm2) but not in the low adolescent-high adult subgroup (-0.12 g/cm2; 95% CI, -0.44 to 0.20 g/cm2) compared with the low adolescent-low adult (reference) subgroup. A sensitivity analysis using a negative-outcome control variable to explore unmeasured confounding supported these findings. The light-intensity trajectories were not associated with femur neck BMD; for example, differences in femur neck BMD between the high decreasing and low nonlinear subgroups were 0.16 g/cm2 (95% CI, -0.08 to 0.40 g/cm2) in male participants and 0.20 g/cm2 (95% CI, -0.05 to 0.44 g/cm2) in female participants.

CONCLUSIONS AND RELEVANCE

Supporting high-intensity physical activity throughout early life may help to maximize peak hip strength and prevent osteoporosis in later life. Replication of our findings in independent studies will be important.

Late subadult ontogeny and adult aging of the human thorax reveals divergent growth trajectories between sexes

Sexual dimorphism is an important feature of adult thorax morphology, but when and how sex-related differences in the ribcage arise during ontogeny is poorly known. Previous research proposed that sex-related size differences in the nasal region arise during puberty. Therefore, we explore whether ribcage sexual dimorphism also arises at that time and whether this sexual dimorphism is maintained until old age. We measured 526 (semi)landmarks on 80 CT-based human ribcage reconstructions, on individuals ranging from 7 to 65 year-old. The 3D coordinates were submitted to the Procrustes superimposition and analyzed. Our results show that the trajectories of thorax size and shape between sexes diverge at around 12 years of age, and continue slightly diverging until old age. The differential ontogenetic trends cause adult male ribcages to become deeper, shorter, and wider than female. Our results are consistent with the evidence from the cranial respiratory system, with the development of sexual dimorphism probably related to changes in body composition during puberty combined with changes in the reproductive system.

Testing for paternal influences on offspring telomere length in a human cohort in the Philippines

OBJECTIVES

Telomeres, emerging biomarkers of aging, are comprised of DNA repeats located at chromosomal ends that shorten with cellular replication and age in most human tissues. In contrast, spermatocyte telomeres lengthen with age. These changes in telomere length (TL) appear to be heritable, as older paternal ages of conception (PAC) predict longer offspring TL. Mouse-model studies raise questions about the potential for effects of paternal experiences on human offspring TL, as they suggest that smoking, inflammation, DNA damage, and stressors all shorten sperm TL. Here, we examined whether factors from the paternal environment predict offspring TL as well as interact with PAC to predict offspring TL.

MATERIALS AND METHODS

Using data from the Philippines, we tested if smoking, psychosocial stressors, or shorter knee height (a measure of early life adversity) predict shorter offspring TL. We also tested if these interacted with PAC in predicting offspring TL.

RESULTS

While we did not find the predicted associations, we observed a trend toward fathers with shorter knee height having offspring with longer TL. In addition, we found that knee height interacted with PAC to predict offspring TL. Specifically, fathers with shorter knee heights showed a stronger positive effect of PAC on offspring TL.

DISCUSSION

While the reasons for these associations remain uncertain, shorter knee height is characteristic of earlier puberty. Since spermatocyte TL increases with the production of sperm, we speculate that individuals with earlier puberty, and its concomitant commencement of production of sperm, had more time to accumulate longer sperm telomeres.

Secular changes in limb lengths and proportions from 1952 to 2011 in children, adolescents, and young adults from Kolkata (India)

OBJECTIVES

The aim of the study was to investigate the intergenerational changes of upper and lower limb lengths as well as the values of the upper, lower limb, and intermembral indicators of children, adolescents, and young adults from Kolkata (India) between 1952 to 1966 and 2005 to 2011.

METHODS

The analysis was based on the results of anthropometric measurements of 7488 Bengali children, adolescents, and young adults. They were included in three cross-sectional surveys, carried out in 1955 to 1966, 1982 to 1983 (only males), and 2005 to 2011. The upper and lower limb lengths were obtained and the upper and lower limb indicators, as well as an intermembral index, were calculated. The differences between the cohorts were assessed using two-way ANOVA.

RESULTS

Positive, statistically significant, secular trends regarding the length of the lower and upper limbs as well as the value of the lower limb index were observed. Negative intergenerational changes were noted for the values of the upper limb indicator and intermembral index, suggesting that the secular increase of the length of the upper limbs was less pronounced than those of the body height and lower limbs length.

CONCLUSIONS

The secular increase regarding the lower limbs length was associated with the socioeconomic progress of the country, but the length of the upper limbs was less sensitive for those factors. It is also important to mention that there is still very little information on those characteristics in general, which further proves the need for similar studies.

Could consanguineous marriage provide a cultural alleviation for the obstetric dilemma?

In placental mammals, a poor fit between the physical dimensions of the fetus and maternal pelvis increases the likelihood of obstructed labour. This problem is especially relevant to humans, as our species demonstrates both unique adaptations in pelvic shape and structure associated with bipedalism, and fetal encephalization. Natural selection is expected to have favoured adaptations that reduce the chances of such mismatch within individual mother-offspring dyads. Here, I hypothesise that the cultural practice of consanguineous marriage may have been favoured, on account of increasing the genetic similarity between mothers and offspring and hence the correlation between maternal and fetal physical dimensions. These benefits could be amplified if consanguineous marriage was accompanied by assortative mating for height. An additional benefit of consanguineous marriage for childbirth is the slight reduction in birth size of such offspring compared to non-consanguineous unions. Although the offspring of consanguineous unions have elevated risks of morbidity and mortality, these risks are moderate and the practice could still have been favoured by selection if the reduction in maternal mortality was greater than the increased mortality among individual offspring. This hypothesis could be tested directly by investigating whether rates of obstructed labour are lower in individuals and populations practising consanguineous marriage. At a broader level, phylogenetic analysis could be conducted to test whether consanguineous marriage appears to have originated in the areas where intensive agriculture was first practiced, as adult height typically fell in such populations, potentially exacerbating the risk of obstructed labour.

The influence of stunting on obesity in adulthood: results from the EPIPorto cohort

Objective

To retrospectively investigate the association between short stature and increased sitting height ratio (SHR) – indicators of stunting – and obesity markers in adults.

Design

Cross-sectional evaluation of the EPIPorto cohort. Weight, height, sitting height and waist circumference were measured. Obesity was assessed for men and women through BMI and waist-to-height ratio (WHtR). Short stature (women, <152 cm; men, <164 cm) and high SHR (women, ≥54·05 %; men, ≥53·25 %) were taken as stunting measures. OR with 95 % CI were computed using logistic regression models.

Setting

Representative sample of adults from EPIPorto, an adult cohort study from Porto, Portugal.

Subjects

A sample of 1682 adults, aged 18–86 years, was analysed.

Results

Higher obesity prevalence was found among women (BMI≥30·0 kg/m2: 25·5v.13·3 %,P<0·001) and a higher proportion of men presented abdominal obesity (WHtR≥0·5: 80·1v.71·1 %,P<0·001). A positive association was found between short stature and obesity measures for women (multivariate-adjusted OR; 95 % CI: 1·75; 1·17, 2·62 for BMI≥30·0 kg/m2; 1·89; 1·24, 2·87 for WHtR≥0·5). Increased SHR was associated with higher likelihood of having BMI≥30·0 kg/m2in both sexes (multivariate-adjusted OR; 95 % CI: 2·10; 1·40, 3·16 for women; 1·92; 1·07, 3·43 for men) but not with WHtR≥0·5.

Conclusions

Different growth markers are associated with obesity in adults. However, this association depends on the population and anthropometric measures used: short stature is associated with a higher risk of presenting excessive weight in women but not in men; SHR is more sensitive to detect this effect in both sexes.

Long-Term Outcomes of Hyperglycemic Preterm Infants Randomized to Tight Glycemic Control

OBJECTIVE

To determine whether tight glycemic control of neonatal hyperglycemia changes neurodevelopment, growth, and metabolism at school age.

STUDY DESIGN

Children born very low birth weight and randomized as hyperglycemic neonates to a trial of tight vs standard glycemic control were assessed at 7 years corrected age, including Wechsler Intelligence Scale for Children Fourth Edition, Movement Assessment Battery for Children 2, visual and neurologic examinations, growth measures, dual X-ray absorptiometry, and frequently sampled intravenous glucose tolerance test. The primary outcome was survival without neurodevelopmental impairment at age 7 years. Outcomes were compared using linear regression, adjusted for sex, small for gestational age, birth plurality, and the clustering of twins. Data are reported as number (%) or mean (SD).

RESULTS

Of the 88 infants randomized, 11 (13%) had died and 57 (74% of eligible children) were assessed at corrected age 7 years. Survival without neurodevelopmental impairment occurred in 25 of 68 children (37%), with no significant difference between tight (14 of 35; 40%) and standard (11 of 33; 33%) glycemic control groups (P = .60). Children in the tight group were shorter than those in the standard group (121.3 [6.3] cm vs 125.1 [5.4] cm; P < .05), but had similar weight and head circumference. Children in the tight group had greater height-adjusted lean mass (18.7 [0.3] vs 17.6 [0.2] kg; P < .01) and lower fasting glucose concentrations (84.6 [6.30] vs 90.0 [5.6] mg⋅dL^-1; P < .05), but no other differences in measures of body composition or insulin-glucose metabolism.

CONCLUSION

Tight glycemic control for neonatal hyperglycemia does not change survival without neurodevelopmental impairment, but reduces height, increases height-adjusted lean mass, and reduces fasting blood glucose concentrations at school age.

TRIAL REGISTRATION

ACTRN: 12606000270516.

Head circumference, leg length and its association with dementia among older adult population in Singapore

BACKGROUND

Head circumference and leg length serve as reliable proxy indicators of early-life environment. Research studies have shown that these anthropometric measurements are associated with cognitive impairment and dementia among older adults. The aim of the present study was to assess the associations between dementia with head circumference and leg length among the older adult population in Singapore. This study also aimed to examine the sociodemographic correlates of these anthropometric measurements.

METHODS

Data were collected from 2565 older adults aged 60 years and above, in a population study on the Well-being of the Singapore Elderly. Head circumference and leg length measurements were obtained, and sociodemographic information was recorded. Dementia diagnosis was made using the 10/66 dementia algorithm. Anthropometric measurements were first stratified into quarters, and then logistic regression analysis was used to examine factors associated with head circumference and leg length, as well as to examine the association between dementia with these measurements.

RESULTS

Sociodemographic correlates of head circumference and leg length include age, gender, ethnicity and education level. Smaller head circumference was independently associated with higher odds of 10/66 dementia (OR = 2.173-2.709). When the regression analysis was stratified by gender, the association was found only in the male sample. Leg length was not significantly associated with dementia after controlling for sociodemographic variables.

CONCLUSION

Smaller head circumference is independently associated with dementia among older adults in Singapore. Findings from this study suggest that risk factors for dementia begin their influence in early life. Copyright © 2017 John Wiley & Sons, Ltd.

The association between social factors and body length proportions in Polish schoolchildren from Lower Silesia

Many studies worldwide have shown that social factors are significantly associated with growth in childhood. However, very few researchers studied influence of social factors on body length proportions. The aim of the present study was the assessment how urbanization level, sibship size and parental education may affect body length proportions in schoolchildren. 325 boys and 335 girls aged 7-18 years were measured in schools in Wrocław, two small towns and villages around these towns. Height, sitting height, leg length , and lower leg length were measured in all children, then relative lengths (in relation to height) were calculated: leg, femur, lower leg, estimated leg and lower leg length to leg length ratio. Height was standardized on age using LMS parameters for CDC 2002 year cohort. Other indices were standardized on age by using residuals variance derived from linear regressions. Four-way analysis of variance was used for height and each index, where independent variables were four social factors. Except for father’s education in boys, no other social factor was significant associated with height. Urbanization level significantly differed almost all indices, whereas father’s education level was significantly associated with relative leg length in girls and estimated leg length in both sexes. Our study has shown that the segments of lower limb seems to be more sensitive than height to the effect of social factors. In Lower Silesia, the level of urbanization is still related to differences in environmental conditions, enough to significantly affect growth of children, especially within the segments of lower limbs.

Body composition and the monitoring of non-communicable chronic disease risk

There is a need for simple proxies of health status, in order to improve monitoring of chronic disease risk within and between populations, and to assess the efficacy of public health interventions as well as clinical management. This review discusses how, building on recent research findings, body composition outcomes may contribute to this effort. Traditionally, body mass index has been widely used as the primary index of nutritional status in children and adults, but it has several limitations. We propose that combining information on two generic traits, indexing both the ‘metabolic load’ that increases chronic non-communicable disease risk, and the homeostatic ‘metabolic capacity’ that protects against these diseases, offers a new opportunity to improve assessment of disease risk. Importantly, this approach may improve the ability to take into account ethnic variability in chronic disease risk. This approach could be applied using simple measurements readily carried out in the home or community, making it ideal for M-health and E-health monitoring strategies.

Blood pressure and the capacity-load model in 8-year-old children from Nepal: Testing the contributions of kidney size and intergenerational effects

Objectives

Growth patterns in early life are increasingly linked with subsequent cardio-metabolic risk, but the underlying mechanisms require elucidation. We have developed a theoretical model of blood pressure, treating it as a function of homeostatic metabolic capacity, and antagonistic metabolic load. We sought to differentiate prenatal and postnatal components of metabolic capacity, and to identify intergenerational contributions to offspring capacity and load.

Methods

We followed up at 8 years a cohort of children originally recruited into a randomized trial of maternal micronutrient supplementation in pregnancy. Maternal anthropometry was measured at recruitment. Offspring anthropometry was measured at birth, 2 years and 8 years. Offspring blood pressure, kidney size, and body composition were measured at 8 years. Regression analysis was used to investigate potential associations of maternal phenotype, birth phenotype, and current body composition with kidney size and blood pressure.

Results

Blood pressure was positively associated with body fat, but negatively associated with birth weight and relative leg length. Kidney size was positively associated with birth weight but not with relative leg length. Adjusting for adiposity, blood pressure was independently negatively associated with birth weight, relative leg length, and kidney length. Maternal height and BMI predicted offspring size at birth and at 8 years, but not blood pressure.

Conclusions

Our data provide support for the capacity-load model of blood pressure in Nepalese children. Fetal and postnatal growth and kidney dimensions all contribute to metabolic capacity. Maternal phenotype contributed to offspring capacity and load, but these associations did not propagate to blood pressure.

Surname-inferred Andean ancestry is associated with child stature and limb lengths at high altitude in Peru, but not at sea level

OBJECTIVES

Native Andean ancestry gives partial protection from reduced birthweight at high altitude in the Andes compared with European ancestry. Whether Andean ancestry is also associated with body proportions and greater postnatal body size at altitude is unknown. Therefore, we tested whether a greater proportion of Andean ancestry is associated with stature and body proportions among Peruvian children at high and low altitude.

METHODS

Height, head circumference, head-trunk height, upper and lower limb lengths, and tibia, ulna, hand and foot lengths, were measured in 133 highland and 169 lowland children aged 6 months to 8.5 years. For highland and lowland groups separately, age-sex-adjusted anthropometry z scores were regressed on the number of indigenous parental surnames as a proxy for Andean ancestry, adjusting for potential confounders (maternal age and education, parity, altitude [highlands only]).

RESULTS

Among highland children, greater Andean ancestry was negatively associated with stature and tibia, ulna, and lower limb lengths, independent of negative associations with greater altitude for these measurements. Relationships were strongest for tibia length: each additional Andean surname or 1,000 m increase at altitude among highland children was associated with 0.18 and 0.65 z score decreases in tibia length, respectively. Anthropometry was not significantly associated with ancestry among lowland children.

CONCLUSIONS

Greater Andean ancestry is associated with shorter stature and limb measurements at high but not low altitude. Gene-environment interactions between high altitude and Andean ancestry may exacerbate the trade-off between chest dimensions and stature that was proposed previously, though we could not test this directly.

The effects of height and BMI on prostate cancer incidence and mortality: a Mendelian randomization study in 20,848 cases and 20,214 controls from the PRACTICAL consortium

BACKGROUND

Epidemiological studies suggest a potential role for obesity and determinants of adult stature in prostate cancer risk and mortality, but the relationships described in the literature are complex. To address uncertainty over the causal nature of previous observational findings, we investigated associations of height- and adiposity-related genetic variants with prostate cancer risk and mortality.

METHODS

We conducted a case-control study based on 20,848 prostate cancers and 20,214 controls of European ancestry from 22 studies in the PRACTICAL consortium. We constructed genetic risk scores that summed each man's number of height and BMI increasing alleles across multiple single nucleotide polymorphisms robustly associated with each phenotype from published genome-wide association studies.

RESULTS

The genetic risk scores explained 6.31 and 1.46% of the variability in height and BMI, respectively. There was only weak evidence that genetic variants previously associated with increased BMI were associated with a lower prostate cancer risk (odds ratio per standard deviation increase in BMI genetic score 0.98; 95% CI 0.96, 1.00; p = 0.07). Genetic variants associated with increased height were not associated with prostate cancer incidence (OR 0.99; 95% CI 0.97, 1.01; p = 0.23), but were associated with an increase (OR 1.13; 95 % CI 1.08, 1.20) in prostate cancer mortality among low-grade disease (p heterogeneity, low vs. high grade <0.001). Genetic variants associated with increased BMI were associated with an increase (OR 1.08; 95 % CI 1.03, 1.14) in all-cause mortality among men with low-grade disease (p heterogeneity = 0.03).

CONCLUSIONS

We found little evidence of a substantial effect of genetically elevated height or BMI on prostate cancer risk, suggesting that previously reported observational associations may reflect common environmental determinants of height or BMI and prostate cancer risk. Genetically elevated height and BMI were associated with increased mortality (prostate cancer-specific and all-cause, respectively) in men with low-grade disease, a potentially informative but novel finding that requires replication.

A cross-sectional study of growth, nutritional status and body proportions in children and adolescents at a medical center specializing in the treatment of cystic fibrosis in Poland

INTRODUCTION

Malnutrition, delayed growth and delayed puberty are commonly seen in children with cystic fibrosis. The aim of this study was to evaluate growth, nutritional status and body proportions in children and adolescents suffering from cystic fibrosis.

MATERIAL AND METHODS

The evaluation was based on 19 somatic measurements and indices calculated from these measurements. Somatic development was evaluated in relation to several factors connected to the clinical picture or the course of the disease. Anthropometric data were extracted from the medical histories of 41 boys and 48 girls diagnosed and treated at the Institute of Mother and Child in Warsaw (Poland). Mean values for somatic parameters and body build indices for the children suffering from CF were compared to those for the reference group.

RESULTS

The results revealed that growth in these children was significantly delayed in comparison to that seen in the healthy population (Z-score = -0.56, p < 0.001). Nutritional status was also adversely affected (Z-score = -0.85, p < 0.001). The children suffered more from a deficit in muscularity than in adiposity (Z-score = -0.75 and Z-score = -0.34, p < 0.01, respectively). This was especially true for boys. The children had infantile body proportions and defects in trunk and chest structure.

CONCLUSIONS

The factors that most affected somatic development were infection by Pseudomonas aeruginosa and the time at which the disease was diagnosed. Chronic infection by P. aeruginosa and type of CFTR mutation were the factors that most affected pulmonary function parameters.

Relationships between neonatal weight, limb lengths, skinfold thicknesses, body breadths and circumferences in an Australian cohort

Background

Low birth weight has been consistently associated with adult chronic disease risk. The thrifty phenotype hypothesis assumes that reduced fetal growth impacts some organs more than others. However, it remains unclear how birth weight relates to different body components, such as circumferences, adiposity, body segment lengths and limb proportions. We hypothesized that these components vary in their relationship to birth weight.

Methods

We analysed the relationship between birth weight and detailed anthropometry in 1270 singleton live-born neonates (668 male) from the Mater-University of Queensland Study of Pregnancy (Brisbane, Australia). We tested adjusted anthropometry for correlations with birth weight. We then performed stepwise multiple regression on birth weight of: body lengths, breadths and circumferences; relative limb to neck-rump proportions; or skinfold thicknesses. All analyses were adjusted for sex and gestational age, and used logged data.

Results

Circumferences, especially chest, were most strongly related to birth weight, while segment lengths (neck-rump, thigh, upper arm, and especially lower arm and lower leg) were relatively weakly related to birth weight, and limb lengths relative to neck-rump length showed no relationship. Skinfolds accounted for 36% of birth weight variance, but adjusting for size (neck-rump, thigh and upper arm lengths, and head circumference), this decreased to 10%. There was no evidence that heavier babies had proportionally thicker skinfolds.

Conclusions

Neonatal body measurements vary in their association with birth weight: head and chest circumferences showed the strongest associations while limb segment lengths did not relate strongly to birth weight. After adjusting for body size, subcutaneous fatness accounted for a smaller proportion of birth weight variance than previously reported. While heavier babies had absolutely thicker skinfolds, this was proportional to their size. Relative limb to trunk length was unrelated to birth weight, suggesting that limb proportions at birth do not index factors relevant to prenatal life.

Do mismatches between pre- and post-natal environments influence adult physiological functioning?

Purpose

Mismatches between pre- and post-natal environments have implications for disease in adulthood. However, less is known about how this mismatch can affect physiological systems more generally, especially at younger ages. We hypothesised that mismatches between pre- and post-natal environments, as measured by the measures of birthweight and adult leg length, would be associated with poorer biomarker levels across five key physiological systems in young adults.

Methods

Data were collected from 923, 36 year-old respondents from the West of Scotland Twenty-07 Study. The biomarkers were: systolic blood pressure (sBP); forced expiratory volume (FEV₁); glycated haemoglobin (HbA_1c); glomerular filtration rate (eGFR); and gamma-glutamyltransferase (GGT). These biomarkers were regressed against pre-natal conditions (birthweight), post-natal conditions (leg length) and the interaction between pre- and post-natal measures. Sex, childhood socioeconomic position and adult lifestyle characteristics were adjusted for as potential effect modifiers and confounders, respectively.

Results

There were no associations between birthweight and leg length and sBP, FEV₁, HbA_1c, or GGT. Higher birthweight and longer leg length were associated with better kidney function (eGFR). However, there was no evidence for mismatches between birthweight and leg length to be associated with worse sBP, FEV₁, HbA_1c, eGFR or GGT levels (P>0.05).

Conclusions

Our hypothesis that early signs of physiological damage would be present in young adults given mismatches in childhood environments, as measured by growth markers, was not proven. This lack of association could be because age 36 is too young to identify significant trends for future health, or the associations simply not being present.

Components of height and blood pressure in childhood

BACKGROUND

In children being taller is associated with higher blood pressure (BP), but few studies have divided height into its components: trunk and leg length. We examined the associations of total height, trunk length and leg length with systolic BP (SBP), diastolic BP (DBP) and pulse pressure (PP) at early childhood and mid-childhood visits, as well as change between the two visits.

METHODS

We obtained five measures of SBP and DBP at the early childhood visit (N = 1153, follow-up rate = 54%) and at the mid-childhood visit (N = 1086, follow-up rate = 51%) respectively, in Project Viva, a US cohort study. We measured total height and sitting height (a measure of trunk length that includes head and neck) and calculated leg length as the difference between the two. Using mixed models, we adjusted the cross-sectional analyses for leg length when trunk length was the exposure of interest, and vice versa. We also adjusted for maternal race/ethnicity, child age, sex, overall adiposity and BP measurement conditions.

RESULTS

At the mid-childhood visit, total height was positively associated with SBP [0.34 (0.24; 0.45) mmHg/cm] but not with DBP [0.07 (-0.003; 0.15)]. In models examining trunk and leg length separately, each was positively associated with SBP [0.72 (0.52; 0.92) and 0.33 (0.16; 0.49) respectively]. In a fully adjusted model with both leg and trunk length, only trunk length remained associated with BP. For a given leg length, a 1-cm increment in trunk length was associated with a 0.63-mmHg (0.42; 0.83) higher SBP and a 0.17-mmHg (0.02; 0.31) higher DBP. For a given trunk length, however, the associations of leg length with SBP [0.13 (-0.03; 0.30)] and with DBP [0.002 (-0.11; 0.12)] were null. These patterns were similar at the early childhood visit.

CONCLUSIONS

Children with greater trunk lengths have higher BPs, perhaps because of the additional pressure needed to overcome gravity to perfuse the brain.

Grandparental education, parental education and child height: evidence from Hong Kong's "Children of 1997" birth cohort

PURPOSE

Adult height is the sum of growth during fetal, infancy, childhood, and puberty, controlled by different biological factors. In long-term developed Western populations, height is positively associated with socioeconomic position, but less clearly so in recently developing populations. We aimed to elucidate socioeconomic influences on height at different growth phases.

METHODS

We examined the associations of parents' education and grandparents' education with birth weight and height gain z-scores during infancy (birth to <2 years), childhood (2 to <8 years), and puberty (8 to <14 years) adjusted for parents' height using generalized estimating equations in Hong Kong's "Children of 1997" birth cohort (n = 8264).

RESULTS

Parents' education, but not grandparents', was positively associated with birth weight (z-score, 0.07; 95% confidence interval [CI] 0.01-0.12 for grade ≥12 compared with grade ≤9) and height gain during infancy (0.11; 95% CI, 0.05-0.18), adjusted for gender, gestational age, initial size, parity, parents' age, parents' birthplace, and parents' height. Conversely, similarly adjusted, grandparents' education, but not parents', was associated with height gain during childhood (0.11; 95% CI, 0.04-0.18).

CONCLUSIONS

Parental education was associated with fetal and infant, but not childhood, linear growth, suggesting the mechanism underlying socioeconomic influences on height at different growth phases may be contextually specific.

Associations between arterial oxygen saturation, body size and limb measurements among high-altitude Andean children

Objectives

The relative influences of hypoxia and other environmental stressors on growth at altitude remain unclear. Previous work demonstrated an association between peripheral arterial oxygen saturation (S_pO₂) and anthropometry (especially tibia length) among Tibetan and Han children at altitude. We investigated whether similar associations exist among Andeans, and the patterning of associations between S_pO₂ and anthropometry.

Methods

Stature, head-trunk height, total upper and lower limb lengths, zeugopod (ulna and tibia) and autopod (hand and foot) lengths were measured in Peruvian children (0.5–14 years) living at >3000 m altitude. S_pO₂ was measured by pulse oximetry. Anthropometry was converted to internal z scores. Correlation and multiple regression were used to examine associations between anthropometry z scores and S_pO₂, altitude, or S_pO₂ adjusted for altitude since altitude is a major determinant of variation in S_pO₂.

Results

S_pO₂ and altitude show weak, significant correlations with zeugopod length z scores and still weaker significant correlations with total upper and lower limb length z scores. Correlations with z scores for stature, head-trunk height, or autopod lengths are not significant. Adjusted for altitude, there is no significant association between anthropometry and S_pO₂.

Conclusions

Associations between S_pO₂ or altitude and total limb and zeugopod length z scores exist among Andean children. However, the relationships are relatively weak, and while the relationship between anthropometry and altitude may be partly mediated by S_pO_2, other factors that covary with altitude (e.g., socioeconomic status, health) are likely to influence anthropometry. The results support suggestions that zeugopod lengths are particularly sensitive to environmental stressors. Am. J. Hum. Biol., 25:629–636, 2013. © 2013 Wiley Periodicals, Inc.

Investigating individual- and area-level socioeconomic gradients of pulse pressure among normotensive and hypertensive participants

Socioeconomic status is a strong predictor of cardiovascular disease. Pulse pressure, the difference between systolic and diastolic blood pressure, has been identified as an important predictor of cardiovascular risk even after accounting for absolute measures of blood pressure. However, little is known about the social determinants of pulse pressure. The aim of this study was to examine individual- and area-level socioeconomic gradients of pulse pressure in a sample of 2,789 Australian adults. Using data from the North West Adelaide Health Study we estimated the association between pulse pressure and three indices of socioeconomic status (education, income and employment status) at the area and individual level for hypertensive and normotensive participants, using Generalized Estimating Equations. In normotensive individuals, area-level education (estimate: -0.106; 95% CI: -0.172, -0.041) and individual-level income (estimate: -1.204; 95% CI: -2.357, -0.050) and employment status (estimate: -1.971; 95% CI: -2.894, -1.048) were significant predictors of pulse pressure, even after accounting for the use of medication and lifestyle behaviors. In hypertensive individuals, only individual-level measures of socioeconomic status were significant predictors of pulse pressure (education estimate: -2.618; 95% CI: -4.878, -0.357; income estimate: -1.683, 95% CI: -3.743, 0.377; employment estimate: -2.023; 95% CI: -3.721, -0.326). Further research is needed to better understand how individual- and area-level socioeconomic status influences pulse pressure in normotensive and hypertensive individuals.

Nutritional status of highland and lowland children in Ecuador

We assessed the nutritional status of children in Ecuador using anthropometric measurements and body composition.

OBJECTIVES

To determine whether living in the highlands in Quito was a predisposing factor to poor nutrition in children.

METHOD

We compared the children in highlands at 2772 m above sea level with their costal (605 m above sea level) counterparts at Santo Domingo de Los Colorados. By using the WHO standard reference 2007, we distinguished malnourished children from healthy children using Z-score of -2 as a cut-off point.

RESULTS

Mean Z-score indices for both height-for-age (HFA) and weight-for-age (WFA) were found to be significantly lower among urban children than for rural children (p < 0.001). Urban children were also four times more likely of becoming mildly stunted (OR = 3.95%, 95% confidence interval (CI): 1.818-8.448) and three times more likely of being mildly underweight (OR = 3.95%, 95% CI: 1.241-7.551).

CONCLUSION

Living in highland urban areas of Ecuador is a predisposing factor for poor nutrition among children.

Trade-offs in relative limb length among Peruvian children: extending the thrifty phenotype hypothesis to limb proportions

Background and Methods

Both the concept of ‘brain-sparing’ growth and associations between relative lower limb length, childhood environment and adult disease risk are well established. Furthermore, tibia length is suggested to be particularly plastic under conditions of environmental stress. The mechanisms responsible are uncertain, but three hypotheses may be relevant. The ‘thrifty phenotype’ assumes that some components of growth are selectively sacrificed to preserve more critical outcomes, like the brain. The ‘distal blood flow’ hypothesis assumes that blood nutrients decline with distance from the heart, and hence may affect limbs in relation to basic body geometry. Temperature adaptation predicts a gradient of decreased size along the limbs reflecting decreasing tissue temperature/blood flow. We examined these questions by comparing the size of body segments among Peruvian children born and raised in differentially stressful environments. In a cross-sectional sample of children aged 6 months to 14 years (n = 447) we measured head circumference, head-trunk height, total upper and lower limb lengths, and zeugopod (ulna and tibia) and autopod (hand and foot) lengths.

Results

Highland children (exposed to greater stress) had significantly shorter limbs and zeugopod and autopod elements than lowland children, while differences in head-trunk height were smaller. Zeugopod elements appeared most sensitive to environmental conditions, as they were relatively shorter among highland children than their respective autopod elements.

Discussion

The results suggest that functional traits (hand, foot, and head) may be partially protected at the expense of the tibia and ulna. The results do not fit the predictions of the distal blood flow and temperature adaptation models as explanations for relative limb segment growth under stress conditions. Rather, our data support the extension of the thrifty phenotype hypothesis to limb growth, and suggest that certain elements of limb growth may be sacrificed under tough conditions to buffer more functional traits.

Epilepsy, poverty and early under-nutrition in rural Ethiopia

PURPOSE

The incidence of epilepsy in Ethiopia is high compared with industrialised countries, but in most cases the cause of epilepsy is unknown. Childhood malnutrition remains widespread. We performed a case-control study to determine whether epilepsy is associated with poverty and markers of early under-nutrition.

METHODS

Patients with epilepsy (n=112), aged 18-45years, were recruited from epilepsy clinics in and around two towns in Ethiopia. Controls with a similar age and gender distribution (n=149) were recruited from patients and relatives attending general outpatient clinics. We administered a questionnaire to define the medical and social history of cases and controls, and then performed a series of anthropometric measurements. Unconditional logistic regression was used to estimate multivariate adjusted odds ratios. Multiple linear regression was used to estimate adjusted case-control differences for continuously distributed outcomes.

RESULTS

Epilepsy was associated with illiteracy/low levels of education, odds ratio=3.0 (95% confidence interval: 1.7-5.6), subsistence farming, odds ratio=2.6 (1.2-5.6) and markers of poverty including poorer access to sanitation (p=0.009), greater overcrowding (p=0.008) and fewer possessions (p<0.001). Epilepsy was also associated with the father's death during childhood, odds ratio=2.2 (1.0-4.6). Body mass index was similar in cases and controls, but patients with epilepsy were shorter and lighter with reduced sitting height (p<0.001), bitrochanteric diameter (p=0.029) and hip size (p=0.003). Patients with epilepsy also had lower mid-upper arm circumference (p=0.011) and lean body mass (p=0.037).

CONCLUSION

Epilepsy in Ethiopia is strongly associated with poor education and markers of poverty. Patients with epilepsy also had evidence of stunting and disproportionate skeletal growth, raising the possibility of a link between early under-nutrition and epilepsy.

Arm length is associated with type 2 diabetes mellitus in Japanese-Americans

AIMS/HYPOTHESIS

The aim of the study was to examine the association of type 2 diabetes mellitus with arm length as a marker for early life environment and development.

METHODS

This was a cross-sectional analysis of 658 second- and third-generation Japanese-Americans (349 men and 309 women). Different arm length (total, upper and forearm length) and leg length (total and lower leg length) measurements were performed. Type 2 diabetes was defined by the use of hypoglycaemic medication, fasting plasma glucose (FPG) ≥ 7 mmol/l or glucose at 2 h ≥ 11.1 mmol/l during an OGTT. Persons meeting the criteria for impaired glucose tolerance were excluded from these analyses (FPG <7 mmol/l and 2 h glucose during an OGGT <11.1 but ≥ 7.8 mmol/l). Multivariable logistic regression was used to estimate associations between prevalence of diabetes and limb length while adjusting for possible confounders.

RESULTS

A total of 145 individuals had diabetes. On univariate analysis, arm and leg length were not associated with diabetes. After adjustment for age, sex, computed tomography-measured intra-abdominal fat area, height, weight, smoking status and family history of diabetes, total arm length and upper arm length were inversely related to diabetes (OR for a 1 SD increase 0.49, 95% CI 0.29, 0.84 for total arm length, and OR 0.56, 95% CI 0.36, 0.87 for upper arm length). Forearm length, height and leg length were not associated with diabetes after adjustment for confounding variables.

CONCLUSIONS/INTERPRETATION

Our findings of associations between arm lengths and prevalence of type 2 diabetes supports a role for factors that determine bone growth or their correlates in the development of this condition.

Maternal education inequalities in height growth rates in early childhood: 2004 Pelotas birth cohort study

Socio-economic inequalities in attained height have been reported in many countries. The aim of this study was to explore the age at which maternal education inequalities in child height emerge among children from a middle-income country. Using data from the 2004 Pelotas cohort study from Brazil we modelled individual height growth trajectories in 2106 boys and 1947 girls from birth to 4 years using a linear spline mixed-effects model. We examined the associations of maternal education with birth length and trajectories of growth in length/height, and explored the effect of adjusting for a number of potential confounder or mediator factors. We showed linear and positive associations of maternal education with birth length and length/height growth rates at 0-3 months and 12-29/32 months with very little association at 3-12 months, particularly in boys. By age 4 years the mean height of boys was 101.06 cm (SE = 0.28) in the lowest and 104.20 cm (SE = 0.15) in the highest education category (mean difference 3.14 cm, SE = 0.32, P < 0.001). Among girls the mean height was 100.02 cm (SE = 0.27) and 103.03 cm (SE = 0.15) in the lowest and highest education categories, respectively (mean difference 3.01 cm, SE = 0.31, P < 0.001). For both boys and girls there was on average a 3-cm difference between the extreme education categories. Adjusting for maternal height reduced the observed birth length differences across maternal education categories, but differences in postnatal growth rates persisted. Our data demonstrate an increase in the absolute and relative inequality in height after birth; inequality increases from approximately 0.2 standard deviations of birth length to approximately 0.7 standard deviations of height at age 4, indicating that height inequality, which was already present at birth, widened through differential growth rates to age 2 years.

Why socially deprived populations have a faster resting heart rate: impact of behaviour, life course anthropometry, and biology--the RECORD Cohort Study

Although studies have shown that resting heart rate (RHR) is predictive of cardiovascular morbidity/mortality, few studies focused on the epidemiology and social aetiology of RHR. Using the RECORD Cohort Study (7158 participants, 2007-2008, Paris region, France), we investigated individual/neighbourhood socioeconomic variables associated with resting heart rate, and assessed which of a number of psychological factors (depression and stress), behaviour (sport-related energy expenditure, medication use, and alcohol, coffee, and tobacco consumption), life course anthropometric factors (body mass index, waist circumference, and leg length as a marker of childhood environmental exposures), and biologic factors (alkaline phosphatase and gamma-glutamyltransferase) contributed to the socioeconomic disadvantage-RHR relationship. Combining individual/neighbourhood socioeconomic factors in a socioeconomic score, RHR increased with socioeconomic disadvantage: +0.9 [95% credible interval (CrI): +0.2, +1.6], +1.8 (95% CrI: +1.0, +2.5), and +3.6 (95% CrI: +2.9, +4.4) bpm for the 3 categories reflecting increasing disadvantage, compared with the lowest disadvantage category. Twenty-one percent of the socioeconomic disadvantage-RHR relationship was explained by sport practise variables, 9% by waist circumference, 7% by gamma-glutamyltransferase, 5% by alkaline phosphatase, and 3% by leg length. Future research should further clarify the mechanisms through which socioeconomic disadvantage influences resting heart rate, as a pathway to social disparities in cardiovascular morbidity/mortality.

How useful is BMI in predicting adiposity indicators in a sample of Maya children and women with high levels of stunting?

OBJECTIVES

Body mass index (BMI) is used frequently to estimate adiposity levels in children and adults. However, the applicability of BMI to populations with high levels of stunting has been questioned. Stunted people can have disproportionately short legs, which may increase BMI without increasing body fat because of the relatively larger trunk compared with the legs.

METHODS

A sample of 57 urban Maya schoolchildren, aged 7-9 years (31 boys), and 53 adult women underwent anthropometric assessments and bioelectrical impedance analysis. Multiple linear regression was performed to determine whether the ability of BMI to predict adiposity indicators is altered by stunting and sitting height ratio (SHR). The adiposity indicators were waist circumference, sum of skinfolds, upper arm muscle area, upper arm fat area, and arm fat index.

RESULTS

BMI was the strongest predictor of all adiposity indicators and in most cases, explained more of the variance in adiposity of Maya children than Maya women. Abdominal adiposity was better predicted by BMI than peripheral adiposity in Maya women and Maya children. Stunting was significant in predicting adiposity in some models but never substantially changed the variance explained. SHR was never a significant predictor.

CONCLUSIONS

The relationship between BMI and adiposity indicators is not changed by stunting status or body proportions in this short population of urban Maya children and women. BMI can be used as an indicator of adiposity for these children but not the women. It is recommended that BMI is used in conjunction with other estimates of body composition.