Evidence for relatively greater subcutaneous fat deposition in stunted girls in the North West Province, South Africa, as compared with non-stunted girls

C-reactive protein (CRP) in high altitude Bolivian peri-urban adolescents varies by adiposity, current illness, height, socioeconomic status, sex, and menarcheal status: The potential benefits and costs of adipose reserves in arduous environments

OBJECTIVES

In non-industrialized and low-income populations, adipose stores can serve as a valuable buffer against harsh conditions such as seasonal food scarcity. However, these reserves may incur costs due to adipocytes' production of pro-inflammatory cytokines; inflammation is associated with increased risk for cardiometabolic diseases later in life. Life history theory posits that, especially in populations with high juvenile mortality, higher adiposity may nonetheless be advantageous if its benefits in early life outweigh its later costs. Relatively little is known about adolescents' C-reactive protein concentration (CRP; an inflammation biomarker) in such environments. We investigated CRP and its associations with several hypothesized predictors in adolescents in an economically diverse peri-urban Andean community.

METHODS

We measured CRP in dried blood spots and collected data on anthropometrics, illnesses, socioeconomic status (SES), and menarcheal status in 59 female and 40 male adolescents ("Alteños", 11.0-14.9 years old) with normal vital signs in El Alto, Bolivia (~4150 m amsl). We used Cole's LMS method to standardize all anthropometrics for sex and age, and principal components analysis to construct a "fat-factor" variable loading on these standardized z-scores. We used multiple linear regression to assess the influence of fat-factor and other likely predictors on CRP rank.

RESULTS

Compared to a national Bolivian growth reference, Alteños were, on average, shorter and leaner; only 6% were classified as overweight and none were obese. Pre-menarche females were on average leaner than post-menarche females. The best-fitting model explained 24% of the variance in CRP rank. Significant predictors were fat-factor, SES, current illness for males and pre-menarche females, and z-height for females.

CONCLUSIONS

Our results are consistent with a tradeoff between investments in growth versus immune functioning, as might be expected in an environment with limited resources and high pathogen exposure (e.g., soil-transmitted helminths, poor sanitation). Thinner Alteños appear to maintain a minimum CRP concentration independent of fat-factor, while fatter (or less-thin) Alteños' CRP rises with fat-factor. Female Alteños appear to be trading off investment in immune response for investment in growth and maturation. Alteños' high rate of stunting and absence of obesity suggests chronic, presumably multifactorial, stress. Adipose stores likely buffer against some of these stressors and, in an environment such as this-in which many lack sufficient nutritious foods, potable water, adequate sewage, and health care-may confer a net lifetime benefit.

The Relationship between Under-Nutrition and Hypertension among Ellisras Children and Adolescents Aged 9 to 17 Years

Background: Globally, under-nutrition and hypertension in children has been associated with the risk of developing cardiovascular disease (CVD) in adulthood. The main objective of this study was to investigate the relationship between under-nutrition and hypertension, furthermore, to determine the risk of developing hypertension due to under-nutrition. Methods: The study comprised of 1701 participants (874 boys and 827 girls) between the ages of 9 and 17 years old. All anthropometric and blood pressure measurements were taken according to standard procedures. Mid-upper arm circumference (MUAC), body mass index (BMI), upper arm fat area (UFA), total upper arm area (TUAA) and upper arm muscle area (UMA) of Ellisras children were compared with the National Health and Nutrition Examination Survey III reference population. The linear regression models were used to determine the relationship between under-nutrition with hypertension for unadjusted and then adjusted for age and gender. The logistic regression model was used to determine the risk of under-nutrition on developing hypertension for unadjusted and adjusted for age and gender. Results: There was a positive significant (p < 0.0001) association between all under-nutrition variables (MUAC, BMI, UFA, TUAA and UMA) and systolic blood pressure (SBP; beta ranges between 0.84 and 2.78), and diastolic blood pressure (DBP; beta ranges between 0.3 and 1.08 before adjusting and after adjusting for age and gender (SBP, beta ranges between 0.59 and 2.00 and DBP (beta ranges between 0.24 and 0.80. Conclusion: The prevalence of under-nutrition was high while the prevalence of hypertension was low in this study. The mean under-nutrition variables (BMI, UFA, UMA and MUAC) of Ellisras children were far lower compared to the NHANES III reference population. Hypertension was significantly associated with under-nutrition in this study.

The correlation of intake phytate and tannin on serum transferrin receptor and hemoglobin in stunted overweight adolescents

Stunted overweight teenagers are at risk of having iron deficiency. Iron deficiency is caused by various factors including the high food absorption inhibitors of iron such as phytate and tannins. Phytate and tannin contain polyphenol compounds which have a strong ability to bind iron so that it inhibits iron absorption in the intestine. This study aims to analyze the correlation between phytate, tannin intake and serum transferrin receptor (sTfR) and hemoglobin in stunted overweight adolescents. The research method was a cross-sectional study of 64 stunted overweight adolescents selected by consecutive sampling in four high schools/vocational high schools in Banyumanik District, Semarang City. Phytate and tannin intake data using SQ-FFQ method. The serum transferrin receptor examination uses the ELISA method and the hemoglobin level uses the Cyanomethemoglobin method. The results of the study, most of the respondents had high phytate and tannin intake of 96.9% and 89.1%. Respondents with low serum transferrin receptor were 7.8% and low hemoglobin levels were 7.8%. There was no  correlation between phytate intake with serum transferrin receptor or hemoglobin (p1 = 0.937 r1 = -0.010, p2 = 0.192 r2 = 0.165). Tannins were significantly correlated with serum transferrin receptor and hemoglobin (p1 = 0.005 r1 = 0.344, p2 = 0.002 r2 = -0.374). Based on multivariate analysis, tannin is a determinant of hemoglobin (R2 = 0.257). Conclusion is that tannin is positively correlated with serum transferrin receptor and hemoglobin in stunted overweight adolescents. Excessive tannin intake can cause deficiency in stunted overweight adolescents.

Emerging Early Actions to Bend the Curve in Sub-Saharan Africa's Nutrition Transition

BACKGROUND

Sub-Saharan Africa is the last region to undergo a nutrition transition and can still avoid its adverse health outcomes.

OBJECTIVE

The article explores emerging responses to "bend the curve" in sub-Saharan Africa's nutrition transition to steer public health outcomes onto a healthier trajectory.

METHODS

Early responses in 3 countries at different stages of food system transformation are examined: South Africa-advanced, Ghana-intermediate, and Uganda-early. By comparing these with international experience, actions are proposed to influence nutrition and public health trajectories as Africa's food systems undergo rapid structural change.

RESULTS

Arising from rapid urbanization and diet change, major public health problems associated with overweight are taking place, particularly in South Africa and among adult women. However, public health responses are generally tepid in sub-Saharan Africa. Only in South Africa have policy makers instituted extensive actions to combat overweight and associated noncommunicable diseases through regulation, education, and public health programs. Elsewhere, in countries in the early and middle stages of transition, public health systems continue to focus their limited resources primarily on undernutrition. Related pressures on the supply side of Africa's food systems are emerging that also need to be addressed.

CONCLUSIONS

Three types of intervention appear most feasible: maternal and child health programs to simultaneously address short-term undernutrition problems while at the same time helping to reduce future tendencies toward overweigh; regulatory and fiscal actions to limit access to unhealthy foods; and modernization of Africa's agrifood food system through job skills training, marketing reforms, and food industry entrepreneurship.

Stunting and obesity in childhood: a reassessment using longitudinal data from South Africa

BACKGROUND

A series of cross-sectional studies have found a relationship between stunting and obesity in childhood. Because height appears in both the numerator of indices of stunting and the denominator of indices of obesity, random errors made by fieldworkers measuring heights can produce negative bias in estimates of this relationship.

METHODS

With longitudinal data, height can be instrumented with its lagged value in a two-stage probit regression model, purging the estimated association between the probability of being obese or underweight and the height-for-age z-score of this errors-in-variables bias. Such a model is fitted to a cohort of 1110 primary-school-age children measured in 1993-2004 in a panel study in KwaZulu-Natal, South Africa. The study also collected detailed data on households' demographic and socio-economic characteristics.

RESULTS

Risk factors for stunting, wasting and obesity differed in this population. Stunting was not associated with childhood obesity in either the cross-sectional or two-stage models. In the cross-sectional analysis, however, random measurement errors masked a negative association between children's height-for-age and their probability of being underweight or wasted that emerged in the two-stage instrumental variable models. This association was further amplified, rather than attenuated, by controlling for children's household income, racial group, residence and mother's education.

CONCLUSIONS

The validity of the findings of earlier cross-sectional studies of the association between stunting and obesity in childhood is dependent on the precision with which they measured height. Random measurement error can also mask an association between being stunted and underweight in cross-sectional studies.

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.

The nutrition transition in Africa: can it be steered into a more positive direction?

The objective of this narrative review is to examine the nutrition transition and its consequences when populations in Africa modernize as a result of socio-economic development, urbanization, and acculturation. The focus is on the changes in dietary patterns and nutrient intakes during the nutrition transition, the determinants and consequences of these changes as well as possible new approaches in public health nutrition policies, interventions and research needed to steer the nutrition transition into a more positive direction in Africa. The review indicates that non-communicable, nutrition-related diseases have emerged in sub-Saharan Africa at a faster rate and at a lower economic level than in industrialized countries, before the battle against under-nutrition has been won. There is a putative epigenetic link between under- and over-nutrition, explaining the double burden of nutrition-related diseases in Africa. It is concluded that it is possible to steer the nutrition transition into a more positive direction, provided that some basic principles in planning public health promotion strategies, policies and interventions are followed. It is suggested that sub-Saharan African countries join forces to study the nutrition transition and implemented interventions on epidemiological, clinical and molecular (genetic) level for better prevention of both under- and over-nutrition.

Significant differences between serum CRP levels in children in different categories of physical activity: the PLAY study

Summary

Low-grade systemic inflammation is emerging as a component of the metabolic syndrome. The purpose of this study was to assess the association between serum C-reactive protein (CRP), physical activity and body composition in 193 black children aged 13 to 18 years from a South African township. Demographic information and anthropometric measurements were taken, and fasting blood samples were analysed for high-sensitivity serum CRP. Body fat was measured by air displacement plethysmography.

There was a trend towards higher serum CRP in the boys with a higher percentage body fat. After multiple regression analyses, waist circumference in the girls was significantly associated with serum CRP. In the boys, there was an inverse correlation between percentage body fat and fitness, and between fitness and serum CRP. Significant differences were found between serum CRP in the different physical activity categories, with lower serum CRP in the girls in the higher physical activity group. Obesity should be prevented in South African children by encouraging physical activity.

Adolescents with mild stunting show alterations in glucose and insulin metabolism

Purpose. To evaluate glucose and insulin profiles in adolescents with mild stunting and overweight in order to assess the possibility of increased predisposition to diabetes. Subjects and Methods. The study population consisted of 66 pubertal adolescents classified as mildly stunted (height-for-age z scores ≥-2 and <-1) or of normal stature, as well as overweight (body mass index ≥85th percentile) or normal weight. Beta-cell function and insulin resistance were evaluated according to the homeostasis model assessment (HOMA). Results. In the group with mild stunting, glucose, insulin, and HOMA-IR levels were significantly higher in overweight adolescents compared with those of normal weight, whereas HOMA-B levels were significantly lower. Adolescents with mild stunting showed significantly higher accumulations of body and abdominal fat than their normal stature counterparts. Conclusions. The presence of mild stunting was associated with higher levels of glucose and insulin, diminished function of beta cells, and increased insulin resistance. These results reinforce the need for intervention in adolescents with mild stunting.

Childhood overweight and obesity among Kenyan pre-school children: association with maternal and early child nutritional factors

Objective

To report on the prevalence of overweight and obesity among pre-school children in Kenya and examine the associations between childhood overweight and selected maternal and child-related factors.

Design

Demographic Health Survey data, multistage stratified cluster sampling methodology.

Setting

Rural and urban areas of Kenya.

Subjects

A total of 1495 children between the ages of 3 and 5 years in Kenya.

Results

Over 30 % of the children were stunted, approximately 16 % were underweight, 4 % were wasted, approximately 18 % were overweight and 4 % were obese; 8 % were both overweight/obese and stunted. Maternal overweight and obesity, higher levels of maternal education, being a large or very large child at birth, and being stunted were each associated with higher odds of overweight and obesity among Kenyan children. Older children and large household size were each associated with lower odds of overweight and obesity among Kenyan children.

Conclusions

The analysis demonstrates the presence of under- and overnutrition among Kenyan pre-school children and the importance of focusing on expanding efforts to prevent and treat malnutrition within this population. It also identifies some of the modifiable factors that can be targeted in these efforts.

Relationship between birthweight and arterial elasticity in childhood

There is a considerable debate about the potential influence of ‘fetal programming’ on cardiovascular diseases in adulthood. In the present prospective epidemiological cohort study, the relationship between birthweight and arterial elasticity in 472 children between 5 and 8 years of age was assessed. LAEI (large artery elasticity index), SAEI (small artery elasticity index) and BP (blood pressure) were assessed using the HDI/PulseWave™ CR-2000 CardioVascular Profiling System. Blood concentrations of glucose, total cholesterol and its fractions [LDL (low-density lipoprotein)-cholesterol and HDL (high-density lipoprotein)-cholesterol] and triacylglycerols (triglycerides) were determined by automated enzymatic methods. Insulin was assessed by a chemiluminescent method, insulin resistance by HOMA (homoeostasis model assessment) and CRP (C-reactive protein) by immunonephelometry. Two linear regression models were applied to investigate the relationship between the outcomes, LAEI and SAEI, and the following variables: birthweight, gestational age, glucose, LDL-cholesterol, HDL-cholesterol, triacylglycerols, insulin, CRP, HOMA, age, gender, waist circumference, per capita income, SBP (systolic BP) and DBP (diastolic BP). LAEI was positively associated with birthweight (P=0.036), waist circumference (P<0.001) and age (P<0.001), and negatively associated with CRP (P=0.024) and SBP (P<0.001). SAEI was positively associated with birthweight (P=0.04), waist circumference (P=0.001) and age (P<0.001), and negatively associated with DBP (P<0.001). Arterial elasticity was decreased in apparently healthy children who had lower birthweights, indicating an earlier atherogenetic susceptibility to cardiovascular diseases in adolescence and adult life. Possible explanations for the results include changes in angiogenesis during critical phases of intrauterine life caused by periods of fetal growth inhibition and local haemodynamic anomalies as a way of adaptation to abnormal pressure and flow.

Habitual physical activity and body composition of black township adolescents residing in the North West Province, South Africa

Objective

It is known that stunting and obesity affect a large proportion of children in the world, and these can be affected by the physical activity levels of the children. In the present study, we evaluated the association between physical activity, physical development and body composition in black adolescent children.

Design

Cross-sectional study.

Setting

Black township schools in the North West Province, South Africa.

Methods

Three-hundred and thirteen grade 8 children were included in the Physical Activity in Youth study. Anthropometric measurements, body composition measures and maturity level as assessed by Tanner stages were determined in these children. In addition, Previous Day Physical Activity Recall questionnaires were administered on the children to record the various activities they undertake daily.

Results

The demographic characteristics of the children showed a high level of homogeneity. A high prevalence of stunting (16.3%) was observed in the children, which was higher in boys than in girls (21.6 vs. 12.3%). Also prevalent was overweight/obesity (8.6%), but this was higher in girls than in boys (13.4 vs. 1.6%). The children also showed a reduction in levels of physical activity with advancement in maturity; furthermore, boys showed a more central form of fat deposition whilst girls showed more gynoid deposition.

Conclusions

The study revealed that physical activity plays a role in determining body composition, and further indicated that physical activity is associated with favourable body composition measures. Children who were more active were likely to have less fat deposits.

Differences and similarities regarding adiponectin investigated in African and Caucasian women

OBJECTIVE

Concentrations of adiponectin, an adipocytokine with insulin-sensitizing actions, may vary according to ethnic group. This study aimed to determine whether fasting adiponectin levels of Caucasian and African women differ. A second objective was to determine which components of the metabolic syndrome are more closely related to adiponectinemia in both groups.

DESIGN

A cross-sectional study including 102 urban African and 115 Caucasian women with a wide range of obesity aged 20-55 years.

METHODS

Anthropometric measurements were taken, namely weight, height, body mass index, waist circumference, and hip circumference. Cardiovascular measurements included blood pressure and arterial compliance. Fasting blood samples were taken to determine glucose, insulin, C-peptide, leptin, adiponectin, and lipid levels.

RESULTS

Mean adiponectin levels of the whole groups did not differ, but normal weight African women (N = 38) showed marginally lower adiponectin levels than their Caucasian counterparts (N = 41; P = 0.047). No differences in adiponectin were shown for overweight and obese women. Separate multiple regression analyses for ethnic groups showed that only homeostasis model assessment-insulin resistance (HOMA-IR) significantly contributed to the variance in adiponectin levels of African women, whereas leptin, triacylglycerol levels and HOMA-IR contributed significantly to adiponectin variance in Caucasian women. An additional multiple regression analysis in a combined ethnic group (N = 217) showed ethnicity to be a significant contributor to variances in adiponectin levels.

CONCLUSIONS

Even though adiponectin levels of these ethnic groups are similar, different associations of adiponectin with leptin and triacylglycerol levels might indicate that there are ethnic differences regarding the mechanistic functions of adiponectin within the scope of the metabolic syndrome.

Poverty and household food security of black South African farm workers: the legacy of social inequalities

Objective

To assess socio-economic indicators, nutritional status and living conditions of farm workers and their families, with the purpose to develop research and intervention programmes aimed at enhancing nutritional status and quality of life.

Design and setting

Three farm schools in two districts of the North-West Province and farming communities were selected. Anthropometrical measurements, structured face-to-face questionnaires and focus group discussions were carried out in 2002 and 2003 by a multidisciplinary research team.

Results

Access to electricity, water and sanitation, as well as monthly food rations or subsidies, vary and depend on farm owners. The majority of adults have education below or up to grade four, farm schools provide only up to grade seven. Distance to farm schools and intra-household issues hamper children's attendance and performance at school. Household food security is compromised due to a lack of financial resources, infrastructure and also household resource allocation. This impacts negatively especially on children, with half of them being underweight, stunted or wasted. Employment is usually linked to men, while most women have access to casual jobs only. Insecurity of residence and the perceived disempowered position towards farm owners add to feelings of hopelessness and stress.

Conclusions and recommendations

This study highlights destitute living conditions of farm worker families. Apart from structural and financial constraints, paternalistic structures of the past might also hamper development. Based on these findings, follow-up research projects and in-depth investigations into underlying social issues with regard to nutrition insecurity and livelihoods of farm workers were initiated.

Obesity in South Africa: challenges for government and health professionals

Objectives

To review data on the prevalence, causes and health consequences of obesity in South Africa and propose interventions to prevent and treat obesity and related outcomes.

Methods

Data from existing literature were reviewed with an emphasis on changing eating and activity patterns, cultural factors, perceptions and beliefs, urbanisation and globalisation. Results of studies on the health consequences of obesity in South Africans are also reviewed.

Results

Shifts in dietary intakes and activity patterns to higher fat intakes and lower physical activity are contributing to a higher prevalence of obesity. Few overweight black women view themselves as overweight, and some associate thinness with HIV/AIDS. Glucose and lipid toxicity, associated with insulin resistance, play roles in the pathogenesis of the co-morbid diseases of obesity. Elevated free fatty acids in the black population predispose obese black patients to type 2 diabetes.

Conclusion and recommendations

Obesity prevention and treatment should be based on education, behaviour change, political support, intersectoral collaboration and community participation, local actions, wide inclusion of the population, adequately resourced programmes, infiltration of existing initiatives, evidence-based planning, and proper monitoring and evaluation. Interventions should have the following components: reasonable weight goals, healthful eating, physical activity and behavioural change. Genes and mutations affecting susceptibility to the development of co-morbidities of obesity and vulnerable periods of life for the development of obesity should be prioritised. Prevention should be managed in community services, identification of high-risk patients in primary healthcare services and treatment of co-morbid diseases in hospital services.