Infant growth and body composition from birth to 24 months: Are infants developing the same?

Background: Given the importance of infancy for establishing growth trajectories, with later-life health consequences, we investigated longitudinal body composition among infants from six economically and ethnically diverse countries.Methods: We recruited mother-infant dyads using the WHO Multicenter Growth Reference Study criteria. We measured fat-free mass (FFM) in 1393 (49% female) infants from birth to 6 months of age (Australia, India, and South Africa; n = 468), 3-24 months of age (Brazil, Pakistan, South Africa, and Sri Lanka; n = 925), and derived fat mass (FM), fat mass index (FMI), and fat-free mass index (FFMI). Height-for-age (HAZ), weight-for-age (WAZ), and weight-for-length (WHZ) Z-scores were computed. Sex differences were assessed using a t-test, and country differences using a one-way analysis of covariance. We further compared subsamples of children with average (-0.25 \u3e HAZ \u3c +0.25), below-average (≤-0.25) and above-average (≥+0.25) HAZ.Results: HAZ performed well between 0 and 6 months, but less so between 3 and 24 months. The stunting prevalence peaked at 10.3% for boys and 7.8% for girls, at 24 months. By 24 months, girls had greater FMI (10%) than boys. There were significant differences in FFM (both sexes in all countries) and FM (Brazilian boys, Pakistani and South African girls) by 24 months of age between infants with average, above-average, and below-average HAZ.Conclusion: In a multi-country sample representing more ideal maternal conditions, body composition was heterogeneous even among infants who exhibited ideal length. Having a mean HAZ close to the median of the WHO standard for length reduced FFM between-country heterogeneity but not FM, suggesting that other factors may influence adiposity

Enough is not enough: Medical students’ knowledge of early warning signs of childhood cancer

Background. The reported incidence of childhood cancer in upper-middle-income South Africa (SA) is much lower than in high-income countries, partly due to under-diagnosis and under-reporting. Documented survival rates are disturbingly low, prompting an analysis of potential factors that may be responsible.Objectives. To determine final-year medical students’ level of knowledge of early warning signs of childhood cancer and whether a correlation existed between test scores and participants’ age, gender and previous exposure to a person with cancer.Methods. A two-part questionnaire based on the Saint Siluan mnemonic, testing both recall and recognition of early warning signs of childhood cancer, was administered. The Mann-Whitney-Wilcoxon test was used to assess differences in continuous and count variables between demographic data, experience and responses, and Fisher’s exact test and Spearman’s rank correlation coefficient were used to determine correlations between demographic data, previous contact with persons with cancer and test scores. A novel equality ratio was calculated to compare the recall and recognition sections and allowed analysis of recall v. recognition.Results. The 84 participants recalled a median of six signs each (interquartile range 4 - 7) and correctly recognised a median of 70% in the recognition section, considered a pass mark. There was no correlation between participants’ age, gender, previous contact with a person with cancer and recognition scores. Students with previous exposure to a person with cancer had higher scores in the recall section, but this did not achieve statistical significance. Students were able to recognise more signs of haematological malignancies than central nervous system (CNS) malignancies.Conclusion. The study demonstrated a marked inconsistency between recall and recognition of signs of childhood cancer, with signs of CNS malignancies being least recognised. However, the majority of students could recognise enough early warning signs to meet the university pass standard. Although this study demonstrated acceptable recognition of early warning signs of childhood cancer at one university, we suggest that long-term recall in medical practitioners is poor, as reflected in the low age-standardised ratios of childhood cancer in SA. We recommend increased ongoing exposure to paediatric oncology in medical school and improved awareness programmes to increase early referrals.

Stunting in infancy, pubertal trajectories and adult body composition: the Birth to Twenty Plus cohort, South Africa.

BACKGROUND/OBJECTIVES: Childhood rapid growth and earlier puberty onset have been associated with adult obesity. However, the association between childhood stunting, pubertal timing and adult obesity is unclear. We examined whether the relationship between stunting at age 2 years (y) and body composition at 23 years is mediated by adolescent body mass index, and pubertal development, using the Birth-to-Twenty Plus cohort (South Africa). SUBJECTS/METHODS: For 1036 participants, data on anthropometrics between birth and 23 years, maternal factors, and pubertal development (Tanner scale at 9-16 years) were collected. Stunting at 2 years (height-for-age z-score < -2), 5-18 years BMI-for-age trajectories, pubertal development trajectories, and DXA-derived fat mass (FM) and fat free mass (FFM) at 23 years were determined. Data were analysed using hierarchical regressions and structural equation models. RESULTS: Stunting was directly associated with slower pubertal development and with shorter adult stature, but was not associated with adolescent BMI trajectories, adult FM or FFM. However, stunting was indirectly associated with adult FM and FFM through the direct associations between slower pubertal development and lower FM and between shorter height and lower FFM. BMI trajectories were independently associated with FM and FFM. CONCLUSIONS: Being stunted in this population predicted adult body composition through slower pubertal development and shorter adult stature

Racial differences in the growth of the axial and appendicular skeleton and bone mass in 11 year old South African children.

Introduction Ethnic differences in bone growth and proportions have previously been investigated in relation to bone fragility. Differential growth in the axial and appendicular skeletons has been suggested to predispose to differential susceptibility to fracture. The developmental origins of bone size and osteoporosis have also been investigated. However, the impact of foetal programming on body proportions and limb lengths in unknown. Objectives The aim of this study was to investigate the presence of ethnic and sex differences in axial and appendicular growth. Additionally, it was to investigate the impact of early life factors on skeletal dimensions and proportions in childhood . Methods Anthropometric measurements of stature, weight, sitting height and limb lengths were taken on 368 black and white, male and female 9 year old children. DXA scans of the distal ulna;distal radius; hip and lumbar spine were also obtained. The same measurements were obtained for 197 of the black children who had birthweight and weight and length data at 1 year. For the first part of the analyses, Analyses of Covariance were performed to assess differences in limb lengths adjusted for differences in stature. Multiple regression analyses were used to assess significant predictors of site-specific bone mass. Comparisons were made after adjustment for weight, weight and stature and weight and regional segment lengths. For the second part of the analyses, Analyses of Covariance were performed to assess differences in stature and regional segment lengths at different tertiles of birthweight, and weight and height at 1 year. Stepwise multiple regressions were performed with early life growth patterns to assess significant predictors of stature and regional segment lengths at 10 years. Results Black children had longer limbs but shorter trunks than white children. Regional segment length were a more significant predictor of site-specific bone mass than stature. In black boys birthweight had positive but weak associations with stature and regional segment length while in girls the association were marginal. In contrast, weight and height at 1yr had strong associations with stature and regional segment lengths. Conclusion There is a differential effect of ethnicity and sex on the growth of the axial and appendicular skeletons, and regional segment length is a better predictor of site-specific bone mass than stature. Early life growth has a long-term influence on stature, as well as on regional segment lengths but marginal effect on body proportions

The prevalence of malnutrition and growth percentiles for urban South African children

Abstract Background Low- and middle-income countries (LMIC) are experiencing a double-burden of malnutrition characterised by high prevalence of both under- and over-nutrition. We set out using data from the mixed-longitudinal Birth-to-Twenty Plus (Bt20+) birth cohort, to evaluate the patterns of malnutrition and growth in a large South African (SA) city by; (i) assessing the prevalence of undernutrition from birth to 5 years of age and overweight and obesity from ages 2 to 21 years in black and white, male and female children, and (ii) determining percentiles for height, weight, BMI, waist and hip circumferences and comparing the centiles to American and Dutch references. Methods Height, weight, waist and hip circumferences were measured on urban black and white SA children from the Bt20+. A total of 3273 children born between April and June 1990 in the Greater Johannesburg Metropolitan area were included in the cohort. Z-scores were derived using the WHO 2006 child growth standards (0–5 years), for defining stunting, underweight and wasting. The International Obesity Task Force (IOTF) references were used to define overweight and obesity. Percentiles were developed using the lambda mu sigma (LMS) method and compared to American and Dutch references. Results Black children were consistently shorter and black males lighter than white children and American references. The prevalence of stunting peaked at 2 years and was significantly higher in males than females and in black than white children. Black females had a greater prevalence of overweight and obesity than black males from 10 to 17 years. The percentiles for black females for weight and BMI were similar to those of South African white and American references but both black and white South African females had lower waist circumferences than American references. Conclusion The growth percentiles show that young South African urban black females are experiencing general but not central obesity due to a secular change which is faster in weight than height. High levels of undernutrition persist alongside high levels of over-nutrition with adolescence being a critical period for the upsurge in obesity in females. Early intervention is needed to combat the rise in obesity

Effects of Ethnicity and Sex on the Growth of the Axial and Appendicular Skeleton of Children Living in a Developing Country

Provides information on results of a study of the Birth to Ten children at age nine investigating whether there are ethnic and sex differences in axial and appendicular dimensions of South African children and whether regional segment length is a better predictor of bone mass than stature

The association between the timing, intensity and magnitude of adolescent growth and body composition in early adulthood.

OBJECTIVES: There's paucity of longitudinal studies assessing the role of adolescent growth on adult body composition in developing countries. The aims of this study were to assess the association between adolescent change in height, weight and BMI and early adult height, weight, body fat and lean mass. METHODS: Magnitude, timing and intensity of height, weight and BMI growth were modelled for participants from the Birth to Thirty (Bt30) cohort (7-23 years). Early adult height, weight, BMI and DXA-derived body composition were obtained 1881 black participants (21-24 years). Linear regression analyses were used to assess associations. RESULTS: Adolescents with an earlier onset of puberty were heavier in childhood and had an earlier timing and faster weight gain velocity in late adolescence. The intensity of adolescent weight gain was positively associated with adult BMI and fat mass index (FMI) in females. Early timing of adolescent BMI gain was associated with increased weight and BMI in adult females and FMI in adult males. Achieving peak weight velocity around age at peak height velocity was associated with lower BMI and fat mass in both sexes. CONCLUSION: This study confirms the adverse consequences of excessive weight gain prior to puberty, which is associated with an earlier and faster resurgence in weight gain velocity in early adulthood. Factors that contribute to an asynchronous timing of ages of peak weight and peak height velocities may accentuate the risk of adult obesity

Social vulnerability, parity and food insecurity in urban South African young women: the healthy life trajectories initiative (HeLTI) study.

Social vulnerability indices (SVI) can predict communities vulnerability and resilience to public health threats such as drought, food insecurity or infectious diseases. Parity has yet to be investigated as an indicator of social vulnerability in young women. We adapted an SVI score, previously used by the US Centre for Disease Control (CDC), and calculated SVI for young urban South African women (n = 1584; median age 21.6, IQR 3.6 years). Social vulnerability was more frequently observed in women with children and increased as parity increased. Furthermore, young women classified as socially vulnerable were 2.84 times (95% CI 2.10-3.70; p &lt; 0.001) more likely to report household food insecurity. We collected this information in 2018-2019, prior to the current global COVID-19 pandemic. With South Africa having declared a National State of Disaster in March 2020, early indicators suggest that this group of women have indeed been disproportionally affected, supporting the utility of such measures to inform disaster relief efforts

Social vulnerability, parity and food insecurity in urban South African young women: the healthy life trajectories initiative (HeLTI) study

Social vulnerability indices (SVI) can predict communities’ vulnerability and resilience to public health threats such as drought, food insecurity or infectious diseases. Parity has yet to be investigated as an indicator of social vulnerability in young women. We adapted an SVI score, previously used by the US Centre for Disease Control (CDC), and calculated SVI for young urban South African women (n = 1584; median age 21.6, IQR 3.6 years). Social vulnerability was more frequently observed in women with children and increased as parity increased. Furthermore, young women classified as socially vulnerable were 2.84 times (95% CI 2.10–3.70; p &lt; 0.001) more likely to report household food insecurity. We collected this information in 2018–2019, prior to the current global COVID-19 pandemic. With South Africa having declared a National State of Disaster in March 2020, early indicators suggest that this group of women have indeed been disproportionally affected, supporting the utility of such measures to inform disaster relief efforts.</p