BackgroundElevated blood pressure in childhood is a risk factor for adult hypertension which is a global health problem. Excess adiposity in childhood creates a predisposition to develop adult hypertension. Our aim was to explore distinct sex-specific adiposity trajectories from childhood to late adolescence and examined their association with blood pressure.MethodsLatent Class Growth Mixture Modeling (LCGMM) on longitudinal data was used to derive sex-specific and distinct body mass index (BMI: kg/m2) trajectories. We studied 1824 black children (boys = 877, girls = 947) from the Birth to Twenty (Bt20) cohort from Soweto, South Africa, and obtained BMI measures at ages 5 through 18 years. Participants with at least two age-point BMI measures, were included in the analysis. Analysis of variance (ANOVA), chi-square test, multivariate linear and standard logistic regressions were used to test study characteristics and different associations.ResultsWe identified three (3) and four (4) distinct BMI trajectories in boys and girls, respectively. The overall prevalence of elevated blood pressure (BP) was 34.9 % (39.4 % in boys and 30.38 % in girls). Boys and girls in the early onset obesity or overweight BMI trajectories were more likely to have higher BP values in late adolescence. Compared to those in the normal weight BMI trajectory, girls in early onset obesity trajectories had an increased risk of elevated BP with odds ratio (OR) of 2.18 (95 % confidence interval 1.31 to 4.20) and 1.95 (1.01 to 3.77). We also observed the weak association for boys in early onset overweight trajectory, (p-value = 0.18 and odds ratio of 2.39 (0.67 to 8.57))ConclusionsDistinct weight trajectories are observed in black South African children from as early as 5 years. Early onset adiposity trajectories are associated with elevated BP in both boys and girls. It is important to consider individual patterns of early-life BMI development, so that intervention strategies can be targeted to at-risk individuals.

ObjectiveSocial epidemiology models suggest that socioeconomic status (SES) mobility across the life course affects blood pressure. The aim of this study was to investigate the association between SES change between infancy and adolescence, and blood pressure, in young adults, and the impact of early growth on this relationship.SettingData for this study were obtained from a ‘Birth to Twenty’ cohort in Soweto, Johannesburg, in South Africa.ParticipantsThe study included 838 Black participants aged 18 years who had household SES measures in infancy and at adolescence, anthropometry at 0, 2, 4 and 18 years of age and blood pressure at the age of 18 years.MethodsWe computed SES change using asset-based household SES in infancy and during adolescence as an exposure variable, and blood pressure and hypertension status as outcomes. Multivariate linear and logistic regressions were used to investigate the associations between SES change from infancy to adolescence, and age, height and sex-specific blood pressure and hypertension prevalence after adjusting for confounders.ResultsCompared to a persistent low SES, an upward SES change from low to high SES tertile between infancy and adolescence was significantly associated with lower systolic blood pressure (SBP) at the age of 18 years (β=−4.85; 95% CI −8.22 to −1.48; p<0.01; r2=0.1804) after adjusting for SES in infancy, small-for-gestational-age (SGA) and weight gain. Associations between SES change and SBP were partly explained by weight gain between birth and the age of 18 years. There was no association between SES mobility and diastolic blood pressure, mean arterial pressure or hypertension status.ConclusionsOur study confirms that upward SES change has a protective effect on SBP by the time participants reach young adulthood. Socioeconomic policies and interventions that address inequality may have the potential to reduce cardiovascular disease burden related to BP in later life.

BackgroundHypertension is an emerging public health problem in South Africa. Recent evidence from longitudinal studies has shown that hypertension in adulthood can be traced back to childhood. There is scarcity of longitudinal data on paediatric blood pressure (BP) particularly in African populations. The objective of this study is to assess the prevalence of hypertension and evaluate BP tracking between childhood and late adolescence among South African black Children.MethodsThis study utilized data from the Birth to Twenty cohort, which is comprised of children born in Soweto, Johannesburg in 1990 (N = 3273, 78.5 % black). Data on BP and anthropometry were collected at six follow-up periods between ages 5 and 18 years. Blood pressure status was classified using the Fourth report on National High Blood pressure program in children and adolescents. Pearson correlation coefficients and relative risk ratios (RR) were used to describe tracking of BP between childhood and late adolescence.ResultsThe overall point prevalence ranged from 9.2 to 16.4 % for prehypertension and 8.4 to 24.4 % for hypertension. Tracking coefficients ranged from 0.20 to 0.57 for SBP and 0.17- 0.51 for DBP in both sexes over the 14 years of measurement. The proportion of children who maintained an elevated BP status between childhood, adolescence and age 18 years ranged from 36.1 % at age 5 years to 56.3 % at age 13 years. Risk of having elevated BP at 18 years ranged from; RR: 1.60 (95 % CI: 1.29–2.00) at 5 years to RR: 2.71 (95 % CI: 2.32–3.17) at 14 years of age.ConclusionsThis study reports high prevalence of elevated BP which tracks from early childhood into late adolescence. These findings emphasize the importance of early identification of children at risk of developing elevated BP and related risk factors plus timely intervention to prevent hypertension in adulthood.

Background Anaemia in pregnancy is associated with adverse obstetric outcomes. When detected early in pregnancy, it can be treated; however, information on its prevalence and associated factors is limited in rural Ghana. Aim The aim of this study was to determine the prevalence and maternal factors associated with anaemia in pregnancy at first antenatal care (ANC) visits. Setting The study was conducted in the Navrongo War Memorial Hospital, a secondary referral facility in the Kassena-Nankana district in rural northern Ghana. Methods A retrospective analysis of antenatal clinic records of pregnant women collected from January to December 2014. All pregnant women initiating antenatal clinic, who had initial haemoglobin (Hb) levels measured, were included in the study. Logistic regression analyses were carried out to determine factors associated with anaemia at the initiation of ANC. Results We analysed data from 506 women with median Hb of 11.1 g/dL (IQR 7.31–13.8). The median gestational age at booking was 14 weeks (5–36 weeks). The prevalence of anaemia was 42.7%, with 95% confidence interval (CI) [38.4–47.1], and was high among teenage mothers (52% [34.9–67.8]), mothers who booked in the third trimester (55% [33.6–74.7]) and grand multiparous women (58% [30.7–81.6]). Factors associated with anaemia included grand multiparity (odds ratio [OR] = 1.94 with 95% CI [1.58–2.46]), booking during the third trimester (OR = 2.06 [1.78–2.21]) and mother who were underweight compared to those with normal weight (OR = 3.17 [1.19–8.32]). Conclusion Burden of anaemia in pregnancy is still high in rural northern Ghana. We advocate further strengthening of the primary health care system to improve early access to ANC delivery. Keywords anaemia in pregnancy; booking visit; maternal and child health; Navrongo; rural; Ghana.

Early growth is associated with blood pressure measured on one occasion, but whether early life growth patterns are associated with longitudinal blood pressure trajectories is under-researched. Therefore, we sought to examine the association between early growth and blood pressure trajectories from childhood to adulthood. Blood pressure was measured on seven occasions between ages 5 and 18 years in the Birth to Twenty cohort study and conditional variables for growth in infancy and mid-childhood were computed from anthropometric measures (n=1937, 52% girls). We used a group-based trajectory modeling approach to identify distinct height-adjusted blood pressure trajectories and then tested their association with growth between birth and mid-childhood adjusting for several covariates. Three trajectory groups were identified for systolic and diastolic blood pressure: ‘lower’, ‘middle’ and ‘upper’ in boys and girls, separately. In boys, predictors of the middle or upper systolic blood pressure trajectories versus the lower trajectory were in birth weight (odds ratio [OR] 0.75[95% CI 0.58–0.96] per SD) and relative weight gain in infancy (4.11[1.25–13.51] per SD). In girls, greater relative weight gain and linear growth in both infancy and mid-childhood were consistently associated with an almost 2-fold higher likelihood of being in the upper versus lower systolic blood pressure trajectory. The associations for the diastolic blood pressure trajectories were inconsistent. These findings emphasize the importance of identifying children at risk of progression to high blood pressure. Accelerated growth in infancy and mid-childhood may be a key target for early life intervention in prevention of elevated blood pressure progression.

Background.Violence against children is a significant cause of personal suffering and long-term ill health, poor psychological adjustment, and a range of social difficulties, including adverse effects intergenerationally. Objectives. Using a large corpus of longitudinal data collected in the Birth to Twenty Plus cohort, to give an overview of exposure to and experience of violence, as well as perpetration of violence, across childhood, reported contemporaneously by several informants. This overcomes limitations of retrospectively recalled information collected from one person at one point in time. Methods. We identified 280 data points relating to exposure to and perpetration of violence in 14 of the 21 waves of data collection from birth to 22 years of age. Data were classified into four developmental stages (preschool, primary school years, adolescence and young adulthood) and seven categories (exposure to violence in the community, home and school; exposure to peer violence; being a victim of violence, excluding sexual violence; sexual violence; and perpetration of violence). Both descriptive and inferential statistics were employed to analyse the data. Results. Over the past two decades, only 1% of the sample had not been exposed to or experienced violence in their home, school and/or community. Two-thirds of children of schoolgoing age were reported as having been exposed to community violence, and more than half of all children to violence in their home. Reports of sexual violence increased from 10% among primary school-aged children to ~30% among adolescents and young adults. Over the course of their lives, ~40% of children were reported as having been exposed to or being victims of five or six of the categories of violence coded in this analysis. High levels of violence perpetration were reported across childhood. Age and gender differences in exposure to and experience and perpetration of violence were evident, and all categories of violence were more prevalent among poorer and more disadvantaged groups. Conclusions. Very high levels of violence were reported in all the settings of urban South African children's lives: home, community, school, among peers and in their intimate relationships. Children and youth were also reported to perpetrate high levels of violence. The personal and social costs of violence are very high, resulting in major public health problems due to its avoidable effects on short-and long-term mental and physical health and social adjustment, and intergenerationally.

BackgroundThe growing prevalence of overweight and obesity in low- or middle-income countries precipitates the need to examine early life predictors of adiposity.ObjectivesTo examine growth trajectories from birth, and associations with adult body composition in the Birth to Twenty Plus Cohort, Soweto, South Africa.MethodsComplete data at year 22 was available for 1088 participants (536 males and 537 females). Conditional weight and height indices were generated indicative of relative rate of growth between years 0–2, 2–5, 5–8, 8–18, and 18–22. Whole body composition was measured at year 22 (range 21–25 years) using dual energy x-ray absorptiometry (DXA). Total fat free soft tissue mass (FFSTM), fat mass, and abdominal visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) were recorded.ResultsBirth weight was positively associated with FFSTM and fat mass at year 22 (β = 0.11, p<0.01 and β = 0.10, p<0.01 respectively). Relative weight gain from birth to year 22 was positively associated with FFSTM, fat mass, VAT, and SAT at year 22. Relative linear growth from birth to year 22 was positively associated with FFSTM at year 22. Relative linear growth from birth to year 2 was positively associated with VAT at year 22. Being born small for gestational age and being stunted at age 2 years were inversely associated with FFSTM at year 22.ConclusionsThe importance of optimal birth weight and growth tempos during early life for later life body composition, and the detrimental effects of pre- and postnatal growth restriction are clear; yet contemporary weight-gain most strongly predicted adult body composition. Thus interventions should target body composition trajectories during childhood and prevent excessive weight gain in early adulthood.

Early life nutrition and growth are related to subsequent obesity risk in high-income countries. We investigated the association between nutrition and growth during infancy, and body composition at 10 years of age in 140 children selected from the Bone Health sub-study of the Birth-to-Twenty cohort from Soweto, Johannesburg, South Africa. Infant feeding and dietary data were collected during the first 12 months, and weight and height were measured at 1 and 2 years of age. At 10 years, anthropometry and dual-energy X-ray absorptiometry (DXA)-derived body composition were measured. Regression models were used to determine associations between independent and dependent variables at the 1% level of significance. A one z-score increase in birth weight was associated with a 1051 g increase in lean mass and a 0.22 increase in body mass index (BMI) z-score at the age of 10 years. After adjusting for confounders, stunting at age 1 year was associated with lower fat mass only at 10 years of age while at age 2 years, it was associated with lower lean mass only. Being underweight at one year of age was significantly associated with lower lean mass only. Weight-for-age (WAZ) change in the second year of infancy was a predictor of fat mass and BMI only. Body fatness at 10 years of age was positively associated with infant WAZ change rather than height-for-age change. There were no significant associations between infant dietary patterns, wasting and being underweight at age 2 years and pre-pubertal body composition. Further studies are needed to assess whether these associations continue during adolescence as pubertal development may be an important modifier of these associations.