Eating attitudes in a group of 11-year-old urban South African girls

No Abstract. South African Journal of Clinical Nutrition Vol. 19(2) 2006: 80-8

How can we learn about community socioeconomic status and poverty in a developing country urban environment? An example from Johannesburg-Soweto, South Africa

Few tested tools exist to assess poverty and socio-economic status at the community level, particularly in urban developing country environments. Furthermore, there is no real sense of what the community concept actually means. Consequently, this paper aims to describe how formative qualitative research was used to develop a quantitative tool to assess community SES in Johannesburg-Soweto in terms of the terminology used, topics covered, and how it was administered, comparing it to the South African Living Standards and Measurement Study. It also discusses the level of aggregation respondents identified as defining a local community using a drawing/mapping exercise. Focus groups (n=11) were conducted with 15-year-old adolescents and their caregivers from the 1990 Birth-to-Twenty (Bt20) cohort and key informant in-depth interviews (n=17) with prominent members working in the Bt20 communities. This research recognises the importance of involving local people in the design of data collection tools measuring poverty and human well-being

Socio-economic status and body composition outcomes in urban South African children

Objective: To determine which aspects of socio-economic status (SES) measured at birth and 9/10 years are associated with body composition at ages 9/10 years. Design: Mixed longitudinal cohort Setting: Johannesburg-Soweto South Africa Participants: A sub-sample of the Birth to Twenty (Bt20) cohort (n=281) with data on birthweight, height, weight, fat and lean tissue (whole body DXA), and birth and 9/10 years SES measures. Main Outcome Measures: Linear regression was used to estimate the influence of birth and ages 9/10 years SES measures on three outcomes; fat mass index (FMI) (Fat Mass (Kg)/height(m)4), lean mass index (LMI) (lean mass (Kg)/height(m)2), and BMI at ages 9/10 years controlling for sex, age, birthweight and pubertal status. Results: Compared to the lowest SES tertile, being in the highest birth SES tertile was associated with increased LMI at 9/10 years (β = 0.43, SE = 0.21 for White and Black children and β = 0.50, SE = 0.23 for Black children only), whereas children in the high SES tertile at 9/10 years had increased FMI (β = 0.46, SE = 0.22 for White and Black children and β = 0.65, SE = 0.23 for Black children only). SES at birth and 9/10 years accounted for 8 and 6% of the variance in FMI and BMI respectively (Black children). Conclusions: These findings underline the importance of examining SES across childhood ages when assessing nutrition inequalities. Results emphasise the need to consider lean and fat mass as well as BMI when studying SES andbody composition in children

Prevalence of rickets-like bone deformities in rural Gambian children.

The aim of this study was to estimate the burden of childhood rickets-like bone deformity in a rural region of West Africa where rickets has been reported in association with a low calcium intake. A population-based survey of children aged 0.5-17.9 years living in the province of West Kiang, The Gambia was conducted in 2007. 6221 children, 92% of those recorded in a recent census, were screened for physical signs of rickets by a trained survey team with clinical referral of suspected cases. Several objective measures were tested as potential screening tools. The prevalence of bone deformity in children <18.0 years was 3.3%. The prevalence was greater in males (M = 4.3%, F = 2.3%, p < 0.001) and in children <5.0 years (5.7%, M = 8.3%, F = 2.9%). Knock-knee was more common (58%) than bow-leg (31%) or windswept deformity (9%). Of the 196 examined clinically, 36 were confirmed to have a deformity outside normal variation (47% knock-knee, 53% bow-leg), resulting in more conservative prevalence estimates of bone deformity: 0.6% for children <18.0 years (M = 0.9%, F = 0.2%), 1.5% for children < 5.0 years (M = 2.3%, F = 0.6%). Three of these children (9% of those with clinically-confirmed deformity, 0.05% of those screened) had active rickets on X-ray at the time of medical examination. This emphasises the difficulties in comparing prevalence estimates of rickets-like bone deformities from population surveys and clinic-based studies. Interpopliteal distance showed promise as an objective screening measure for bow-leg deformity. In conclusion, this population survey in a rural region of West Africa with a low calcium diet has demonstrated a significant burden of rickets-like bone deformity, whether based on physical signs under survey conditions or after clinical examination, especially in boys < 5.0 years

Association of socioeconomic status change between infancy and adolescence, and blood pressure, in South African young adults: Birth to Twenty Cohort

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

In urban South Africa, 16 year old adolescents experience greater health equality than children

Despite the strongly established link between socio-economic status (SES) and health across most stages of the life-course, the evidence for a socio-economic gradient in adolescent health outcomes is less consistent. This paper examines associations between household, school, and neighbourhood SES measures with body composition outcomes in 16 year old South African Black urban adolescents from the 1990 born Birth to Twenty (Bt20) cohort. Multiple regression analyses were applied to data from a sub-sample of the Bt20 cohort (n=346, 53% male) with measures taken at birth and 16 years of age to establish socio-economic, biological and demographic predictors of fat mass, lean mass, and body mass index (BMI). Results were compared with earlier published evidence of health inequality at ages 9-10 years in Bt20. Consistent predictors of higher fat mass and BMI in fully adjusted models were being female, born post term, having a mother with post secondary school education, and having an obese mother. Most measures of SES were only weakly associated with body composition, with an inconsistent direction of association. This is in contrast to earlier findings with Bt20 9-10 year olds where SES inequalities in body composition were observed. Findings suggest targeting obesity interventions at females in households where a mother has a high BMI

How well do waist circumference and body mass index reflect body composition in pre-pubertal children?

Objective: To investigate the quantitative relationship between WC and height and subsequently the association between Waist Circumference Index (WCI), BMI, and body composition in pre-pubertal children. Design: Cross-sectional sample (n = 227; boys = 127) of pre-pubertal Black children (age range 8.8 to 11.0 years) from the Bone Health sub-study of the Bt20 birth cohort study set in Soweto-Johannesburg, South Africa. Measures of height, weight, and waist circumference by anthropometry, total and truncal fat and lean mass by Dual-energy X-ray Absorptiometry (DXA) were used in the analysis. Pearson’s correlation coefficients were used to examine the associations between BMI, WC, and body composition outcomes. Results: WC was independent of height when height was raised to a power of approximately 0.8. BMI and WCI (WC/Ht) were significantly associated with total and truncal fat and lean mass in both sexes (all P < 0.001). BMI demonstrated consistently and significantly higher correlations with body composition than WCI and this association was significantly greater for fat mass than lean mass. Conclusion: BMI, rather than WCI, would be a better screening tool for total and truncal fat mass in both sexes prior to puberty

Is puberty starting earlier in urban South Africa?

Age at the initation of pubertal development was estimated for 401 Black (212 boys) and 206 White (100 boys) urban South African adolescents born in Soweto-Johannesburg in 1990. Average age at the initation of puberty, assessed by age at the transition from Tanner stage 1 to Tanner stage 2 for breast/genitalia or pubic hair development ranged between 9.8 and 10.5 years. There were no statistically significant differences in age at initiation between genders or ethnic groups. Age at the initation of pubertal development has remained stable over the last 10 to 15 years, with the exception of pubic hair in boys which has declined on average 1.3 years over a decade. There is evidence to suggest that the tempo of pubertal maturation is increasing in girls born in the Soweto-Johannesburg area, however, the evidence is less clear for boys

Rickets: An Overview and Future Directions, with Special Reference to Bangladesh: A Summary of the Rickets Convergence Group Meeting, Dhaka, 26–27 January 2006

Rickets has emerged as a public-health problem in Bangladesh during the past two decades, with up to 8% of children clinically affected in some areas. Insufficiency of dietary calcium is thought to be the underlying cause, and treatment with calcium (350–1,000 mg elemental calcium daily) is curative. Despite this apparently simple treatment, little is known about the most appropriate management of bone deformities of affected children, and further studies are needed to determine the details of dosing and duration of calcium therapy, the role of bracing, and specific indications for surgical intervention. Effective preventive measures that can feasibly reach entire communities are needed, and these may differ between various affected regions