Rapidly increasing body mass index among children, adolescents and young adults in a transitioning population, South Africa, 2008-15

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.

Relationship Between National Economic Development and Body Mass Index in Chinese Children and Adolescents Aged 5-19 From 1986 to 2019

Obesity represents a major risk factor for population health. No studies have evaluated how economic expansion impacts the prevalence of obesity. The purpose of this study was to assess the relationship between national economic development and body mass index (BMI) in Chinese children and adolescents. Data of mean BMI in children and adolescents aged 5-19 from 1986 to 2019 were extracted from an international database of cardiometabolic risk factors. Chinese economic development was quantified by the gross domestic product (GDP), which was extracted from the International Monetary Fund. The relationships between GDP and BMI were assessed in 1-year age groups for ages 5-19 years. In addition, the linear regression from the main data and estimated GDP growth allowed the projections of mean BMI for each age group between 2020 and 2025. The results suggest there was a linear increase in BMI over years, which means that there has been a steady increase in BMI over the economic expansion. Overall, 97% of the variance (Pearson correlation coefficient) of BMI in boys can be explained by the GDP expansion, and the same pattern (98% of the variance) occurred in girls. Projected mean BMI were provided for constructing future national strategies to prevent overweight and obesity in youth. In conclusion, BMI in children and adolescents aged 5-19 trended upwards between 1986 and 2019. Our analyses for the first time suggest that globalization has a major impact on BMI in China. Economic expansion was highly predictive of BMI increases.

Stunting and overweight among children in Northeast Brazil: prevalence, trends (1992-2005-2015) and associated risk factors from repeated cross-sectional surveys

Background

A study involving children from Alagoas (Northeast Brazil) revealed that, as a consequence of a drastic reduction in the prevalence of stunting between 1992 to 2005, (22.5 to 11.4%) combined with an increase in overweight prevalence (6.7 to 9.3%), the prevalence of these two conditions in 2005 was very close. If these trends were maintained, it is very likely that, at this time, the childhood overweight prevalence has already exceeded that of the stunting. However, no study is available to confirm this hypothesis. The identification of these changes is relevant to the planning and evaluation of public policies. This study aimed to investigate the prevalence, time trends and associated factors with stunting and overweight in children from Alagoas.

Methods

Independent cross-sectional household surveys were conducted in 1992 (n = 1231), 2005 (n = 1381) and 2015 (n = 988). Data were collected from probabilistic samples of children aged 0–60 months. Stunting was defined by stature-for-age < − 2 sd and overweight by weight-for-stature > 2 sd.

Results

Between 1992, 2005 and 2015, the stunting prevalence was 22.6, 11.2 and 3.2% (reduction of 85.8%), while the overweight prevalence was 6.9, 7.5 and 14.9% (increase of 115.9%), respectively. After multivariate analysis, the following positive associations with stunting were observed in 1992: age group > 24 months (28.3% vs 14.5%), mother with ≥2 children (28.8% vs 12.8%), low birth weight (28.3% vs 15.7%) and mother with low schooling (29.3% vs 7.2%). In 2015 there was a higher prevalence of stunting in males (4.2% vs 2.2%), in children < 24 months (4.6% vs 2.2%), with low birth weight (8.6% vs 3.0%) and in those who had mothers with low schooling (7.0% vs 2.6%). Regarding overweight, in 1992 there was higher prevalence for male (9.1% vs 4.7%) and in children whose mothers had ≤2 children (8.9% vs 5.8%), while in 2015 only birth weight >  4 kg was associated to overweight (27.3% vs 14.2%).

Conclusions

During the analyzed period, there was a significant decrease in stunting prevalence. At the same time, a substantial increase was observed in the overweight prevalence. Currently, stunting is a problem of low magnitude, while overweight has become a worrying public health problem.

Epidemiology of prediabetes and diabetes in Namibia, Africa: A multilevel analysis

BACKGROUND

Diabetes is a leading cause of progressive morbidity and early mortality worldwide. Little is known about the burden of diabetes and prediabetes in Namibia, a Sub-Saharan African (SSA) country that is undergoing a demographic transition.

METHODS

We estimated the prevalence and correlates of diabetes (defined as fasting [capillary] blood glucose [FBG] ≥126 mg/dL) and prediabetes (defined by World Health Organization [WHO] and American Diabetes Association [ADA] criteria as FBG 110-125 and 100-125 mg/dL, respectively) in a random sample of 3278 participants aged 35-64 years from the 2013 Namibia Demographic and Health Survey.

RESULTS

The prevalence of diabetes was 5.1% (95% confidence interval [CI]: 4.2-6.2), with no evidence of gender differences (P = 0.45). The prevalence of prediabetes was 6.8% (95% CI 5.8-8.0) using WHO criteria and 20.1% (95% CI 18.4-21.9) using ADA criteria. Male sex, older age, higher body mass index (BMI), and occupation independently increased the odds of diabetes in Namibia, whereas higher BMI was associated with a higher odds of prediabetes, and residing in a household categorized as "middle wealth index" was associated with a lower odds of prediabetes (adjusted odds ratio 0.71; 95% credible interval 0.46-0.99). There was significant clustering of prediabetes and diabetes at the community level.

CONCLUSIONS

One in five adult Namibians has prediabetes based on ADA criteria. Resources should be invested at the community level to promote efforts to prevent the progression of this disease and its complications.

Lifestyle and socio-economic inequalities in diabetes prevalence in South Africa: A decomposition analysis

BACKGROUND

Inequalities in diabetes are widespread and are exacerbated by differences in lifestyle. Many studies that have estimated inequalities in diabetes make use of self-reported diabetes which is often biased by differences in access to health care and diabetes awareness. This study adds to this literature by making use of a more objective standardised measure of diabetes in South Africa. The study estimates socio-economic inequalities in undiagnosed diabetes, diagnosed diabetes (self-reported), as well as total diabetes (undiagnosed diabetics + diagnosed diabetics). The study also examines the contribution of lifestyle factors to diabetes inequalities in South Africa.

METHODS

This cross sectional study uses data from the 2012 South African National Health and Nutrition Examination Survey (SANHANES-1) and applies the Erreygers Concentration Indices to assess socio-economic inequalities in diabetes. Contributions of lifestyle factors to inequalities in diabetes are assessed using a decomposition method.

RESULTS

Self-reported diabetes and total diabetes (undiagnosed diabetics + diagnosed diabetics) were significantly concentrated amongst the rich (CI = 0.0746; p < 0.05 and CI = 0.0859; p < 0.05). The concentration index for undiagnosed diabetes was insignificant but pro-poor. The decomposition showed that lifestyle factors contributed 22% and 35% to socioeconomic inequalities in self-reported and total diabetes, respectively.

CONCLUSION

Diabetes in South Africa is more concentrated amongst higher socio-economic groups when measured using self-reported diabetes or clinical data. Our findings also show that the extent of inequality is worse in the total diabetes outcome (undiagnosed diabetics + diagnosed diabetics) when compared to the self-reported diabetes outcome. Although in comparison to other determinants, the contribution of lifestyle factors was modest, these contributions are important in the development of policies that address socio-economic inequalities in the prevalence of diabetes.

Tree Species Diversity and Socioeconomic Perspectives of the Urban (Food) Forest of Accra, Ghana

Urban and peri-urban forestry has emerged as a complementary measure to contribute towards eliminating urban hunger and improved nutritional security. However, there is scanty knowledge about the composition, diversity, and socioeconomic contributions of urban food trees in African cities. This paper examines the diversity and composition of the urban forest and food trees of Accra and sheds light on perceptions of urbanites regarding food tree cultivation and availability in the city. Using a mixed methods approach, 105 respondents in six neighborhoods of Accra were interviewed while over 200 plots (100-m2 each) were surveyed across five land use types. Twenty-two out of the 70 woody species in Accra have edible parts (leaves, fruits, flowers, etc.). The food-tree abundance in the city is about half of the total number of trees enumerated. The species richness and abundance of the food trees and all trees in the city were significantly different among land use types (p < 0.0001) and neighborhood types (p < 0.0001). The diversity of food-bearing tree species was much higher in the poorer neighborhoods than in the wealthier neighborhoods. Respondents in wealthier neighborhoods indicated that tree and food-tree cover of the city was generally low and showed greater interest in cultivating food (fruit) trees and expanding urban forest cover than poorer neighborhoods. These findings demonstrate the need for urban food policy reforms that integrate urban-grown tree foods in the urban food system/culture.