Shane A. Norris

Maternal height and child growth patterns

Objective To examine associations between maternal height and child growth during 4 developmental periods: intrauterine, birth to age 2 years, age 2 years to mid-childhood (MC), and MC to adulthood. Study design Pooled analysis of maternal height and offspring growth using 7630 mother–child pairs from 5 birth cohorts (Brazil, Guatemala, India, the Philippines, and South Africa). We used conditional height measures that control for collinearity in height across periods. We estimated associations between maternal height and offspring growth using multivariate regression models adjusted for household income, child sex, birth order, and study site. Results Maternal height was associated with birth weight and with both height and conditional height at each age examined. The strongest associations with conditional heights were for adulthood and 2 years of age. A 1-cm increase in maternal height predicted a 0.024 (95% CI: 0.021-0.028) SD increase in offspring birth weight, a 0.037 (95% CI: 0.033-0.040) SD increase in conditional height at 2 years, a 0.025 (95% CI: 0.021-0.029 SD increase in conditional height in MC, and a 0.044 (95% CI: 0.040-0.048) SD increase in conditional height in adulthood. Short mothers (<150.1 cm) were more likely to have a child who was stunted at 2 years (prevalence ratio = 3.20 (95% CI: 2.80-3.60) and as an adult (prevalence ratio = 4.74, (95% CI: 4.13-5.44). There was no evidence of heterogeneity by site or sex. Conclusion Maternal height influences offspring linear growth over the growing period. These influences likely include genetic and non-genetic factors, including nutrition-related intergenerational influences on growth that prevent the attainment of genetic height potential in low- and middle-income countries.

The Association of 25 Hydroxyvitamin D and Parathyroid Hormone with Metabolic Syndrome in Two Ethnic Groups in South Africa

Introduction Though inconsistent, a number of studies have shown an association between vitamin D (25(OH)D) status, parathyroid hormone (PTH) and the metabolic syndrome (Met S). These have largely been carried out in Caucasians or black subjects living in high income countries. There no data on the relationship of 25(OH)D and PTH status with Met S in populations resident in Africa. The aims of this study were to evaluate if there was an association of 25(OH)D or PTH with Met S in non-Caucasian populations in South Africa, and whether these molecules explained ethnic differences in the prevalence of Met S and its individual components. Methods We measured anthropometry, serum 25(OH)D and PTH levels and the components of Met S, plus related metabolic variables, in 374 African and 350 Asian Indian healthy adults from the greater Johannesburg metropolitan area. Results Met S was diagnosed in 29% of the African and 46% of the Asian Indian subjects (p<0.0001). Subjects with Met S had higher PTH than those without Met S, (p<0.0001), whilst 25(OH)D levels were not significantly different (pu200a=u200a0.50). In multivariate analysis, 25(OH)D was not associated with any components of the Met S however PTH was shown to be positively associated with systolic (pu200a=u200a0.018) and diastolic (pu200a=u200a0.005) blood pressures and waist circumference (p<0.0001) and negatively associated with HOMA (pu200a=u200a0.0008) levels. Logistic regression analysis showed that Asian Indian ethnicity (OR 2.24; 95% CIs 1.57, 3.18; p<0.0001) and raised PTH (OR 2.48; 95% CIs 1.01, 6.08; pu200a=u200a0.04; adjusted for 25(OH)D) produced an increased risk of Met S but 25(OH)D did not (OR 1.25; 95% CI 0.67, 2.24; pu200a=u200a0.48). Conclusions Plasma PTH but not 25(OH)D is an independent predictor of the Met S in African and Asian Indians in South Africa.

Bone mass, body composition and vitamin D status of ARV-naïve, urban, black South African women with HIV infection, stratified by CD4 count

SummaryThis is the first report examining vitamin D status and bone mass in African women with HIV infection using dual-energy X-ray absorptiometry (DXA) with an appropriate HIV-negative control group. Unlike previous publications, it demonstrates no difference in bone mineral density (BMD) or vitamin D status in HIV-positive patients, at different disease stages, vs. HIV-negative subjects.IntroductionLow bone mass and poor vitamin D status have been reported among HIV-positive patients; suggesting HIV or its treatment may increase the risk of osteoporosis, a particular concern for women in countries with high HIV prevalence such as South Africa. We describe bone mass and vitamin D status in urban premenopausal South African women, who were HIV positive but not on antiretroviral therapy (ARV).MethodsThis study is a cross-sectional measurement of BMD and body composition by DXA and vitamin D status by serum 25-hydroxyvitamin D (25(OH)D) concentration. Subjects were recruited into three groups: HIV negative (nu2009=u200998) and HIV positive with preserved CD4 cell count (non-ARV; nu2009=u200974) or low CD4 cell counts prior to ARV initiation (pre-ARV; nu2009=u200975).ResultsThe mean (standard deviation (SD)) age of women was 32.1 (7.2) years. Mean CD4 (SD) counts (×106/l) were 412 (91) and 161 (69) in non-ARV and pre-ARV groups (pu2009<u20090.0001). Pre-ARV women were significantly lighter and had lower mean BMI than the other two groups (pu2009<u20090.002). The pre-ARV group also had significantly less fat and lean mass compared with non-ARV and HIV-negative subjects (pu2009≤u20090.05). After full adjustment, there were no significant differences in BMD at any site (pu2009>u20090.05) between the groups, nor was vitamin D status significantly different between groups (pu2009>u20090.05); the mean (SD) cohort 25(OH)D being 60 (18) nmol/l.ConclusionContrary to previous studies, these HIV-positive women did not have lower BMD or 25(OH)D concentrations than HIV-negative controls, despite the pre-ARV group being lighter with lower BMI.

Genetic diversity in black South Africans from Soweto

BackgroundDue to the unparalleled genetic diversity of its peoples, Africa is attracting growing research attention. Several African populations have been assessed in global initiatives such as the International HapMap and 1000 Genomes Projects. Notably excluded, however, is the southern Africa region, which is inhabited predominantly by southeastern Bantu-speakers, currently suffering under the dual burden of infectious and non-communicable diseases. Limited reference data for these individuals hampers medical research and prevents thorough understanding of the underlying population substructure. Here, we present the most detailed exploration, to date, of genetic diversity in 94 unrelated southeastern Bantu-speaking South Africans, resident in urban Soweto (Johannesburg).ResultsParticipants were typed for ~4.3 million SNPs using the Illumina Omni5 beadchip. PCA and ADMIXTURE plots were used to compare the observed variation with that seen in selected populations worldwide. Results indicated that Sowetans, and other southeastern Bantu-speakers, are a clearly distinct group from other African populations previously investigated, reflecting a unique genetic history with small, but significant contributions from diverse sources. To assess the suitability of our sample as representative of Sowetans, we compared our results to participants in a larger rheumatoid arthritis case–control study. The control group showed good clustering with our sample, but among the cases were individuals who demonstrated notable admixture.ConclusionsSowetan population structure appears unique compared to other black Africans, and may have clinical implications. Our data represent a suitable reference set for southeastern Bantu-speakers, on par with a HapMap type reference population, and constitute a prelude to the Southern African Human Genome Programme.

It's my secret : Barriers to paediatric HIV treatment in a poor rural South African setting

In South Africa, a third of children born are exposed to HIV, while fewer undergo an HIV confirmatory test. Anti-retroviral therapy (ART) coverage among children remains low-despite roll-out of the national ART programme in South Africa in 2004. This study sought to understand critical barriers to seeking HIV-related care for children in rural South Africa. Data presented in this article derive from community-based qualitative research in poor rural villages in north-east South Africa; this includes 21 in-depth interviews in 2008 among caregivers of children identified as HIV-positive in 2007 from a randomly selected community-based sample. Using NVIVO 8, data were coded and analysed, using a constant comparative method to identify themes and their repetitions and variations. Structural barriers leading to poor access to health care, and social and systems barriers, all influenced paediatric HIV treatment seeking. Of concern was the expressed need to maintain secrecy regarding a childs HIV status to avoid stigma and discrimination, and misconceptions regarding the course of HIV disease in children; this led to a delay in seeking appropriate care. These barriers need to be addressed, including through focused awareness campaigns, improved access to health care and interventions to address rural poverty and development at both household and community levels. In addition, training of health care professionals to improve their attitudes and practice may be necessary. However, this study only provides the perspective of the caregivers; further studies with health care providers are needed to gain a fuller picture for appropriate policy and practice guidance.

Psychological and Physical Co-Morbidity among Urban South African Women

Objectives There is substantial evidence for the links between poverty and both physical and mental health; but limited research on the relationship of physical and mental health problems exists in low- and middle-income countries. The objective of this paper is to evaluate the prevalence and co-morbidity of psychological distress among women with common physical diseases in a socio-economically disadvantaged urban area of South Africa. Methods Women enrolled in the Birth to twenty (Bt20) cohort study were evaluated for this paper. Bt20 was founded in 1990 and has followed more than 3,000 children and their caregivers since birth; this study evaluates the health of the caregivers (average age 44) of these children. Psychological distress was evaluated by administering the General Health Questionnaire (GHQ-28) and we evaluated the presence of physical disease by self-report. Results Forty percent of the sample presented with psychological distress using the GHQ scoring method. More than half of the women who reported a history of a physical disease, including diabetes, heart attack, asthma, arthritis, osteoporosis, epilepsy, and tuberculosis, reported psychological disorder. Presence of one physical disease was not associated with increased rates of psychological distress. However, women who reported two diseases had increased rates of psychological symptoms, and this upward trend continued with each additional physical disease reported (measured to five). Conclusions These data indicate high prevalence rates of co-morbid psychological distress among women with physical disease. This argues for the need of greater mental health support for women living with physical diseases.

A two-year history of high bone loading physical activity attenuates ethnic differences in bone strength and geometry in pre-/early pubertal children from a low-middle income country.

We examined the interplay between ethnicity and weight-bearing physical activity on the content and volumetric properties of bone in a pre- to early pubertal South African Black and White population. Sixty six children [Black boys, 10.4 (1.4)yrs, n=15; Black girls, 10.1 (1.2)yrs, n=27; White boys, 10.1 (1.1)yrs, n=7; White girls, 9.6 (1.3)yrs, n=17] reported on all their physical activities over the past two years in an interviewer administered physical activity questionnaire (PAQ). All participants underwent a whole body and site-specific DXA scan and we also assessed bone structure and estimated bone strength with pQCT. Children were classified as being either high or low bone loaders based on the cohorts median peak bone strain score estimated from the PAQ. In the low bone loading group, Black children had greater femoral neck bone mineral content (BMC) (2.9 (0.08)g) than White children (2.4 (0.11)g; p=0.05). There were no ethnic differences in the high bone loaders for femoral neck BMC. At the cortical site, the Black low bone loaders had a greater radius area (97.3 (1.3) vs 88.8 (2.6)mm(2); p=0.05) and a greater tibia total area (475.5 (8.7) vs. 397.3 (14.0)mm(2); p=0.001) and strength (1633.7 (60.1) vs. 1271.8 (98.6)mm(3); p=0.04) compared to the White low bone loaders. These measures were not different between the Black low and high bone loaders or between the Black and White high bone loaders. In conclusion, the present study shows that there may be ethnic and physical activity associations in the bone health of Black and White pre-pubertal children and further prospective studies are required to determine the possible ethnic specific response to mechanical loading.

Dietary intake and body composition in HIV-positive and -negative South African women

OBJECTIVEnThe present paper examines dietary intake and body composition in antiretroviral (ARV)-naïve HIV-positive compared with HIV-negative South African women, as well as the impact of disease severity on these variables.nnnDESIGNnBaseline data from a longitudinal study assessing bone health in HIV-negative and HIV-positive premenopausal South African women over 18 years of age were used. Anthropometry and body composition, measured by dual energy X-ray absorptiometry, were analysed together with dietary intake data assessed using an interviewer-based quantitative FFQ.nnnSETTINGnSoweto, Johannesburg, South Africa.nnnSUBJECTSnBlack, urban South African women were divided into three groups: (i) HIV-negative (HIV-; n 98); (ii) HIV-positive with preserved CD4 counts (HIV+ non-ARV; n 74); and (iii) HIV-positive with low CD4 counts and due to start ARV treatment (HIV+ pre-ARV; n 75).nnnRESULTSnThe prevalence of overweight and obesity was high in this population (59 %). The HIV+ pre-ARV group was lighter and had a lower BMI than the other two groups (all P < 0·001). HIV+ pre-ARV women also had lower fat and lean masses and percentage body fat than their HIV- and HIV+ non-ARV counterparts. After adjustment, there were no differences in macronutrient intakes across study groups; however, fat and sugar intakes were high and consumption of predominantly refined food items was common overall.nnnCONCLUSIONnHIV-associated immunosuppression may be a key determinant of body composition in HIV-positive women. However, in populations with high obesity prevalence, these differences become evident only at advanced stages of infection.

‘We eat together; today she buys, tomorrow I will buy the food’: adolescent best friends’ food choices and dietary practices in Soweto, South Africa

OBJECTIVEnTo explore if and how female adolescents engage in shared eating and joint food choices with best friends within the context of living in urban Soweto, South Africa.nnnDESIGNnA qualitative, exploratory, multiple case study was conducted using semi-structured duo interviews of best friend pairs to ascertain their eating patterns, friendship and social interactions around dietary habits.nnnSETTINGnParticipants were recruited from three high schools in the urban township of Soweto, South Africa.nnnSUBJECTSnFifty-eight female adolescents (twenty-nine friend pairs) still in high school (mean age of 18 years) were enrolled.nnnRESULTSnAlthough overweight rates were high, no association between friends was found; neither did friends share dieting behaviours. Both at school and during visits to the shopping mall, foods were commonly shared and money pooled together by friends to make joint purchases. Some friends carefully planned expenditures together. Foods often bought at school were mostly unhealthy. Availability, price and quality were reported to affect choice of foods purchased at school. Preference shaped joint choices within the shopping mall environment.nnnCONCLUSIONSnFood sharing practices should be investigated in other settings so as to identify specific behaviours and contexts for targeted and tailored obesity prevention interventions. School-based interventions focusing on price and portion size should be considered. In the Sowetan context, larger portions of healthy food may improve dietary intake of fruit and vegetables where friends are likely to share portions.

“You Must Know Where You Come From”: South African Youths’ Perceptions of Religion in Time of Social Change

This study examined South African youths’ perceptions of religion during a period of social and economic transition. In-depth interviews were conducted with 55 Black South African youth (age 18) living in the Johannesburg-Soweto metropolitan area. Data were analyzed in a manner consistent with grounded theory methodology and structural coding. Beliefs about the function of religion were captured by the following themes: provides support, connection to the past, moral compass, promotes healthy development, and intersections between African traditional practices and Christian beliefs. Themes are discussed and directions for future research are presented. In addition, applications of the current research and implications for promoting youths’ resilience are offered.