Determinants of mortality status and population attributable risk fractions of the North West Province, South African site of the international PURE study.

BACKGROUND: Mortality data and comparative risk assessments from sub-Saharan Africa are limited. There is an urgent need for high quality population health surveys to be conducted, to improve the national health surveillance system. Our aim was to perform a comparative risk assesment and report on the mortality status and cause of death data of participants from a South African site of the international Prospective Urban Rural Epidemiology study. METHODS: 1 921 Black participants were included, with a median observational time of 13 years resulting in 21 525 person-years. We performed a comparative risk assessment considering four health status domains: locality (rural vs. urban), socio-economic status (SES) (education and employment), lifestyle factors (physical activity, smoking and alcohol consumption) and prevalent diseases (human immunodeficiency virus (HIV), type 2 diabetes mellitus and hypertension). Next, population-attributable fractions (PAFs) were calculated to determine the mortality risk attributable to modifiable determinants. RESULTS: 577 all-cause deaths occurred. Infectious diseases (28.1% of all deaths) were the most frequent cause of death, followed by cardiovascular disease (CVD) (22.4%), respiratory diseases (11.6%) and cancer (11.1%). The three main contributors to all-cause mortality were HIV infection, high SES and being underweight. HIV infection and underweight were the main contributors to infectious disease mortality and hypertension, the urban environment, and physical inactivity to CVD mortality. HIV had the highest PAF, followed by physical inactivity, alcohol and tobacco use and hypertension (for CVD mortality). CONCLUSION: This African population suffers from a quadruple burden of disease. Urban locality, high SES, prevalent disease (HIV and hypertension) and lifestyle factors (physical inactivity, tobacco and alcohol use) all contributed in varying degrees to all-cause and cause-specific mortalities. Our data confirm the public health importance of addressing HIV and hypertension, but also highlights the importance of physical inactivity, tobacco use and alcohol consumption as focal points for public health strategies to produce the most efficient mortality reduction outcomes.

Female rats consuming an iron and omega-3 fatty acid deficient diet preconception require combined iron and omega-3 fatty acid supplementation for the prevention of bone impairments in offspring.

We previously showed in rats that pre- and postnatal deficiencies in iron and omega-3 (n-3) fatty acids can impair bone development, with additive and potentially irreversible effects when combined. This study aimed to investigate, in female rats consuming a combined iron and n-3 fatty acid deficient (ID + n-3 FAD) diet preconception, whether supplementation with iron and docosahexaenoic/eicosapentaenoic acid (DHA/EPA), alone and in combination, can prevent bone impairments in offspring. Using a 2 × 2 factorial design, female Wistar rats consuming an ID + n-3 FAD diet preconception were randomised to receive an: 1) iron supplemented (Fe + n-3 FAD), 2) DHA/EPA supplemented (ID + DHA/EPA), 3) Fe + DHA/EPA, or 4) ID + n-3 FAD diet from gestational day 10 throughout pregnancy and lactation. Post-weaning, offspring (n = 24/group; male:female = 1:1) remained on the respective experimental diets for three weeks until postnatal day 42-45. Offspring born to female rats consuming a control diet preconception and an Fe+DHA/EPA diet throughout pregnancy and lactation served as non-deficient reference group (Control+Fe+DHA/EPA). Bone mineral density (BMD) was measured using dual-energy X-ray absorptiometry and bone strength using three-point bending tests. Only offspring in the Fe+DHA/EPA group had significantly higher spine and femur BMD, and higher femur stiffness than offspring in the ID + n-3 FAD group, and had similar spine BMD and femur stiffness as the Control + Fe + DHA/EPA group. Offspring in the Fe + DHA/EPA group further had significantly higher femur strength (ultimate load) than the other experimental groups, and a similar femur strength as the Control + Fe + DHA/EPA group. This study shows that only combined iron and DHA/EPA supplementation can prevent bone impairments in offspring of female rats consuming an iron and n-3 FA deficient diet preconception.

Food intake in South African children and retinal microvascular health: The ExAMIN Youth SA study.

BACKGROUND AND AIMS: Retinal arteriolar narrowing and venular widening are associated with increased cardiovascular risk, even at young ages. Whether diet contributes to early microvascular changes in children is not widely explored. We explored the associations of frequency of healthy and unhealthy food group intake with retinal vessel calibers in black and white children. METHODS AND RESULTS: This study included school-aged (5-9 years) black (N = 433, 7.46 ± 0.98 years), and white (N = 403, 7.43 ± 0.82 years) children. Anthropometric and blood pressure measurements were taken, along with retinal vessel calibers (central retinal arteriolar (CRAE) and venular (CRVE) equivalents). Frequencies of food group intake were assessed using a food-frequency questionnaire. A factor analysis was performed to describe food group patters. Independent associations between retinal vessel calibers and frequencies of food group intake and food group patters were explored. In black children, cookies, cakes, and biscuits were associated with narrower arterioles (p < 0.05). In white children, cold sweetened beverages were associated with narrower arterioles (p = 0.02), whereas salty snacks were associated with narrower arterioles (p = 0.01) and wider venules (p < 0.05). Fruits were positively associated with CRAE (p = 0.03) in white children only. CONCLUSION: A higher frequency of unhealthy food group consumption was associated with retinal arteriolar narrowing and venular widening in both black and white children. However, fruit intake was shown beneficial for retinal microvascular health in white children only. Our findings may highlight the importance of promoting healthy eating patterns from early childhood which may reduce the risk of premature cardiovascular disease development.

Effects of egg as an early complementary food on growth of 6- to 9-month-old infants: a randomised controlled trial.

OBJECTIVE: To assess the effect of daily egg consumption for six months on linear growth (primary outcome), weight-for-age, weight-for-length, mid-upper arm circumference-for-age, head circumference-for-age Z-scores, gross motor milestones development, anaemia and iron status (secondary outcomes) in a low socioeconomic community. PARTICIPANTS: Infants aged 6 to 9 months living in the peri-urban Jouberton area, in the Matlosana Municipality, South Africa. DESIGN: A randomised controlled trial with a parallel design was implemented. Eligible infants were randomly allocated to the intervention (n 250) receiving one egg/day and the control group (n 250) receiving no intervention. The participants were visited weekly to monitor morbidity and gross motor development, with information on adherence collected for the intervention group. Trained assessors took anthropometric measurements, and a blood sample was collected to assess anaemia and iron status. There was blinding of the anthropometric assessors to the groups during measurements and the statistician during the analysis. RESULTS: Baseline prevalence of stunting, underweight, wasting, overweight and anaemia was 23·8 %, 9·8 %, 1·2 %, 13·8 % and 29·2 %, respectively, and did not differ between groups. Overall, 230 and 216 participants in the intervention and control groups completed the study, respectively. There was no intervention effect on length-for-age, weight-for-age, weight-for-length Z-scores, gross motor milestone development, anaemia and iron status. CONCLUSIONS: Daily egg intake did not affect linear growth, underweight, wasting, motor milestones development, anaemia and iron status. Other interventions are necessary to understand the effect of animal-source food intake on children's growth and development. This trial was registered at https://clinicaltrials.gov/ (NCT05168085).

Strategies of Modelling Incident Outcomes Using Cox Regression to Estimate the Population Attributable Risk.

When the Cox model is applied, some recommendations about the choice of the time metric and the model's structure are often disregarded along with the proportionality of risk assumption. Moreover, most of the published studies fail to frame the real impact of a risk factor in the target population. Our aim was to show how modelling strategies affected Cox model assumptions. Furthermore, we showed how the Cox modelling strategies affected the population attributable risk (PAR). Our work is based on data collected in the North-West Province, one of the two PURE study centres in South Africa. The Cox model was used to estimate the hazard ratio (HR) of mortality for all causes in relation to smoking, alcohol use, physical inactivity, and hypertension. Firstly, we used a Cox model with time to event as the underlying time variable. Secondly, we used a Cox model with age to event as the underlying time variable. Finally, the second model was implemented with age classes and sex as strata variables. Mutually adjusted models were also investigated. A statistical test to the multiplicative interaction term the exposures and the log transformed time to event metric was used to assess the proportionality of risk assumption. The model's fitting was investigated by means of the Akaike Information Criteria (AIC). Models with age as the underlying time variable with age and sex as strata variables had enhanced validity of the risk proportionality assumption and better fitting. The PAR for a specific modifiable risk factor can be defined more accurately in mutually adjusted models allowing better public health decisions. This is not necessarily true when correlated modifiable risk factors are considered.

Association between maternal postpartum depressive symptoms, socioeconomic factors, and birth outcomes with infant growth in South Africa.

This study aimed to investigate the association between maternal postpartum depressive symptoms, household demographic, socioeconomic, and infant characteristics with infant physical growth, and how these factors correlate to determine latent factors. This study was based on the baseline data of a 6-month randomised controlled trial aimed at providing an egg a day to infants aged 6 to 9-months from a low socioeconomic community in South Africa. Information collected on household demographic, socioeconomic, and infant characteristics was by face-to-face structured interviews, and trained assessors took anthropometric measurements. The Edinburgh Postnatal Depression Scale (EPDS) was used to assess maternal postpartum depressive symptoms. The analysis was based on 428 mother-infant pairs. Total EPDS score and its subscales score were not associated with stunting or underweight risk. However, a three- to four-fold increased risk of stunting and underweight, respectively was observed for premature birth. Low birthweight was associated with an estimated six-fold increased risk of underweight and stunting. Being female was associated with about 50% reduced risk of stunting and underweight. In conclusion, more robust studies are needed to substantiate these findings, with more awareness creation on the consequences of LBW and prematurity on the physical growth of infants from resource-limited settings.

Noncommunicable Disease Conditions and HIV in Rural and Urban South Africa: 2005-2015.

Purpose: Hypertension, obesity, hyperlipidemia, and type 2 diabetes contribute primarily to noncommunicable disease deaths and together with human immunodeficiency virus contribute largely to mortality in South Africa. Our longitudinal study provides the necessary data and insights over a 10-year period to highlight the areas where improved management is required in urban and rural localities. Methods: This study included 536 rural and 387 urban Black participants aged 32 to 93 years from the North-West province, South Africa. Disease prevalence, treatment, and control were determined in 2005 and were re-evaluated in 2015. Multiple measures analyses were used to determine the trends of blood pressure and waist circumference. Results: The initial prevalence of hypertension was 53.2%, obesity was 23.6%, hyperlipidemia was 5.1%, diabetes was 2.9%, and human immunodeficiency virus was 10.7% in 2005. By 2015, the rural population had higher rates of hypertension (63.7% versus 58.5%) and lower rates diabetes (4.3% versus 7.9%) and hyperlipidemia (6.6% versus 18.0%) with similar obesity rates (41.7% versus 42.4%). The average blood pressure levels of urban hypertensives decreased (Ptrend<.001), whereas levels were maintained in the rural group (Ptrend=.52). In both locations, treatment and control rates increased from 2005 to 2015 for all conditions (all ≥6.7%), except for diabetes in which a decrease in control was observed. Waist circumference increased (Ptrend>.001) in both sex and locality groups over the 10-year period. Conclusion: Although average blood pressure of urban hypertensive individuals decreased, urgent measures focused on early identification, treatment, and control of the respective conditions should be implemented to decrease the burden of noncommunicable diseases.

Weight gain in children from birth to 10 years on antiretroviral treatment.

Background: Inadequate weight gain could indicate clinical deterioration in infants and children living with HIV (CLHIV). The World Health Organization's (WHO) weight-for-age z-score (WAZ) growth standards and reference charts are currently used in South Africa to assess weight gain in CLHIV on antiretroviral treatment (ART). Objectives: To assess weight gain patterns of infants and children initiated on ART and to compare weight gain patterns between the WHO WAZ growth standards and population-specific curves constructed from data of CLHIV on ART. Method: A quantitative, retrospective and descriptive-comparative design was used. The weight gain patterns of 98 infants and children from birth to 10 years old during the 24-month period following ART initiation were recorded and assessed using two different growth charts. Results: The children's rate of weight and length gain improved significantly over 24 months since ART initiation, but complete catch-up growth was never achieved. Most (69%) of the children had increased weight gain according to the WAZ growth standard and reference charts versus only 16% according to the HIV-specific weight gain curves. Conclusion: Antiretroviral treatment improved weight and height gain in CLHIV, but the interpretations of weight gain differed significantly between the WHO chart and HIV-specific weight gain curves. Population- and treatment-specific references could improve weight monitoring in CLHIV and assist in the timeous identification of malnutrition.

Comparison of Several Prediction Equations Using Skinfold Thickness for Estimating Percentage Body Fat vs. Body Fat Percentage Determined by BIA in 6-8-Year-Old South African Children: The BC-IT Study.

Body composition measurement is useful for assessing percentage body fat (%BF) and medical diagnosis, monitoring disease progression and response to treatment, and is essential in assessing nutritional status, especially in children. However, finding accurate and precise techniques remains a challenge. The study compares %BF determined by bioelectrical impedance analysis (BIA) and calculated from available prediction equations based on skinfolds in young South African children. A cross-sectional study performed on 202 children (83 boys and 119 girls) aged 6-8 years. Height and weight, triceps and subscapular skinfolds were determined according to standard procedures. %BF was determined with BIA and three relevant available equations. SPSS analyzed the data using paired samples tests, linear regression, and Bland-Altman plots. Significant paired mean differences were found for BIA and Slaughter (t201 = 33.896, p < 0.001), Wickramasinghe (t201 = 4.217, p < 0.001), and Dezenberg (t201 = 19.910, p < 0.001). For all of the equations, the standards for evaluating prediction errors (SEE) were above 5. The Bland-Altman plots show relatively large positive and negative deviations from the mean difference lines and trends of systematic under- and over-estimation of %BF across the %BF spectrum. All three equations demonstrated a smaller %BF than the %BF measured by BIA, but the difference was smallest with the Wickramasinghe equation. In comparison, a poor SEE was found in the three %BF predicted equations and %BF derived from BIA. As such, an age-specific %BF equation incorporating criterion methods of deuterium dilution techniques or 'gold-standard' methods is needed to refute these findings. However, in the absence of developed %BF equations or 'gold-standard' methods, the available prediction equations are still desirable.

Potential of Egg as Complementary Food to Improve Nutrient Intake and Dietary Diversity.

The original aim was to determine the effect of egg consumption on infant growth in a low socioeconomic community in South Africa in a randomized controlled trial. Enrolment was, however, prematurely stopped due to COVID-19 lockdown regulations. The resultant small sample (egg group n = 70; control group n = 85) was followed up to assess the feasibility of egg consumption for eight months in terms of dietary intake, egg usage and perceived effects of lockdown on child feeding. Egg consumption remained low in the control group, <10% consumed egg ≥4 days/week at the follow-up points. In the egg group, egg was frequently consumed at midpoint (daily 87.1%, 4−6 days 8.1%) and endpoint (daily 53.1%, 4−6 days 21.9%). At endpoint, dietary intake of cholesterol and vitamin D was higher, and intake of niacin and vitamin B6 lower in the egg group compared to the control group. Dietary diversity was low, 36.2% of the egg group and 18.9% of the control group (p < 0.05) achieved minimum dietary diversity at endpoint. No babies developed egg allergy or sensitization, and adjusted regression analysis showed that frequency of egg intake was not related with the incidence or duration of allergy-related symptoms. This study showed that frequent egg consumption can contribute safely to complementary food for babies, especially in low- and middle-income countries.

Medications for blood pressure, blood glucose, lipids, and anti-thrombotic medications: relationship with cardiovascular disease and death in adults from 21 high-, middle-, and low-income countries with an elevated body mass index.

AIMS: Elevated body mass index (BMI) is an important cause of cardiovascular disease (CVD). The population-level impact of pharmacologic strategies to mitigate the risk of CVD conferred by the metabolic consequences of an elevated BMI is not well described. METHODS AND RESULTS: We conducted an analysis of 145 986 participants (mean age 50 years, 58% women) from 21 high-, middle-, and low-income countries in the Prospective Urban and Rural Epidemiology study who had no history of cancer, ischaemic heart disease, heart failure, or stroke. We evaluated whether the hazards of CVD (myocardial infarction, stroke, heart failure, or cardiovascular death) differed among those taking a cardiovascular medication (n = 29 174; including blood pressure-lowering, blood glucose-lowering, cholesterol-lowering, or anti-thrombotic medications) vs. those not taking a cardiovascular medication (n = 116 812) during 10.2 years of follow-up. Cox proportional hazard models with the community as a shared frailty were constructed by adjusting age, sex, education, geographic region, physical activity, tobacco, and alcohol use. We observed 7928 (5.4%) CVD events and 9863 (6.8%) deaths. Cardiovascular medication use was associated with different hazards of CVD (interaction P < 0.0001) and death (interaction P = 0.0020) as compared with no cardiovascular medication use. Among those not taking a cardiovascular medication, as compared with those with BMI 20 to <25 kg/m2, the hazard ratio (HR) [95% confidence interval (95% CI)] for CVD were, respectively, 1.14 (1.06-1.23); 1.45 (1.30-1.61); and 1.53 (1.28-1.82) among those with BMI 25 to <30 kg/m2; 30 to <35 kg/m2; and ≥35 kg/m2. However, among those taking a cardiovascular medication, the HR (95% CI) for CVD were, respectively, 0.79 (0.72-0.87); 0.90 (0.79-1.01); and 1.14 (0.98-1.33). Among those not taking a cardiovascular medication, the respective HR (95% CI) for death were 0.93 (0.87-1.00); 1.03 (0.93-1.15); and 1.44 (1.24-1.67) among those with BMI 25 to <30 kg/m2; 30 to <35 kg/m2; and ≥35 kg/m2. However, among those taking a cardiovascular medication, the respective HR (95% CI) for death were 0.77 (0.69-0.84); 0.88 (0.78-0.99); and 1.12 (0.96-1.30). Blood pressure-lowering medications accounted for the largest population attributable benefit of cardiovascular medications. CONCLUSION: To the extent that CVD risk among those with an elevated BMI is related to hypertension, diabetes, and an elevated thrombotic milieu, targeting these pathways pharmacologically may represent an important complementary means of reducing the CVD burden caused by an elevated BMI.

The association between serum vitamin D and body composition in South African HIV-infected women.

BACKGROUND: HIV and antiretroviral therapy (ART) alter vitamin D metabolism, and may be associated with bone loss. OBJECTIVES: The aim of this study was to determine the association between serum 25-hydroxyvitamin D (25(OH)D) and body composition in postmenopausal South African women living with HIV and on ART. METHOD: In this 2-year longitudinal study on 120 women conducted in the North West province of South Africa, serum 25(OH)D concentration, bone mineral density (BMD) at three sites, lean mass and percentage of body fat (%BF) were measured by dual-energy X-ray absorptiometry (DXA). Multivariable linear mixed models were used to assess the association between serum 25(OH)D and body composition over 2 years. Linear mixed models were also used to determine the longitudinal association between lean mass, %BF and BMD. RESULTS: Vitamin D deficiency and insufficiency increased from baseline (10.2% and 19.5%) to 11.5% and 37.5%, respectively, after 2 years. Serum 25(OH)D decreased significantly, however, with a small effect size of 0.39 (P = 0.001), whilst total BMD (effect size 0.03, P = 0.02) and left hip femoral neck (FN) BMD (effect size 0.06, P = 0.0001) had significant small increases, whereas total spine BMD did not change over the 2 years. Serum 25(OH)D had no association with any BMD outcomes. Lean mass had a stronger positive association with total spine and left FN BMD than %BF. CONCLUSION: Serum 25(OH)D was not associated with any BMD outcomes. Maintenance of lean mass could be important in preventing bone loss in this vulnerable group; however, longer follow-up may be necessary to confirm the association.

Factors Associated with Bone Mineral Density and Bone Resorption Markers in Postmenopausal HIV-Infected Women on Antiretroviral Therapy: A Prospective Cohort Study.

The study aimed to determine factors associated with changes in bone mineral density (BMD) and bone resorption markers over two years in black postmenopausal women living with human immunodeficiency virus (HIV) on antiretroviral therapy (ART). Women (n = 120) aged > 45 years were recruited from Potchefstroom, South Africa. Total lumbar spine and left femoral neck (LFN) BMD were measured with dual energy X-ray absorptiometry. Fasting serum C-Telopeptide of Type I collagen (CTx), vitamin D and parathyroid hormone were measured. Vitamin D insufficiency levels increased from 23% at baseline to 39% at follow up. In mixed linear models serum CTx showed no change from baseline to end (p = 0.363, effect size = 0.09). Total and LFN BMD increased significantly over two years, but effect sizes were small. No significant change in spine BMD over time was detected (p = 0.19, effect size = 0.02). Age was significantly positively associated with CTx over time, and negatively with total and LFN BMD. Physical activity (PA) was positively associated with LFN BMD (p = 0.008). Despite a decrease in serum vitamin D, BMD and CTx showed small or no changes over 2 years. Future studies should investigate PA interventions to maintain BMD in women living with HIV.

Association between Objectively Determined Physical Activity Levels and Body Composition in 6-8-Year-Old Children from a Black South African Population: BC-IT Study.

Physical inactivity in children is a global pandemic in parallel with increasing obesity prevalence. However, studies assessing the association between physical activity (PA) and body composition (BC) report conflicting findings, possibly because of the different methodologies across studies, with objective methods promising reliable results. This study determines the association between objectively determined PA levels and BC in 6-8-year-old children from a black South African population. Ninety-three children aged 6-8 years, who formed part of a larger study on BC using the deuterium dilution method (DDM), were included. Height and weight were measured according to the standard procedures, and body mass index z-score was calculated. Fatness was determined by DDM. An accelerometer was used to measure PA levels. Regression models were performed to determine the relationship between PA and BC. Approximately 23% of the children did not meet the recommended PA guidelines and 27% were overfat. After adjustments were made, more time spent in vigorous PA was significantly associated with lower fat mass (ß = -0.25, p = 0.01, 95%CI: -11.08; -1.20) and fat mass % (ß = -0.20, p = 0.04, 95%CI: -12.63; -0.18). Participation in high PA, especially of high intensity, was associated with reduced adiposity in children. Behavioural changes such as increasing high intensity PA is strongly recommended for reducing adiposity.

Lifestyle factors associated with the transition from healthy to unhealthy adiposity among black South African adults over 10 years.

BACKGROUND AND AIMS: Obesity is associated with an increasing prevalence of cardiovascular diseases in Africa, but some obese individuals maintain cardiometabolic health. The aims were to track metabolically healthy overweight or obesity (MHO) over 10 years in African adults and to identify factors associated with a transition to metabolically unhealthy overweight or obesity (MUO). METHODS AND RESULTS: The participants were the South African cohort of the international Prospective Urban and Rural Epidemiological study. From the baseline data of 1937 adults, 649 women and 274 men were followed for 10 years. The combined overweight and obesity prevalence of men (19.2%-23.8%, p = .02) and women (58%-64.7%, p < .001), and the prevalence of the metabolic syndrome in all participants (25.4%-40.2%, p < .001) increased significantly. More than a quarter (26.2%) of the women and 10.9% of men were MHO at baseline, 11.4% of women and 5.1% of men maintained MHO over 10 years, while similar proportions (12.3% of women, 4.7% of men) transitioned to MUO. Female sex, age, and total fat intake were positively associated with a transition to MUO over 10 years, while physical activity was negatively associated with the transition. HIV positive participants were more likely to be MHO at follow-up than their HIV negative counterparts. CONCLUSIONS: One in two black adults with BMI ≥25 kg/m2 maintained MHO over 10 years, while a similar proportion transitioned into MUO. Interventions should focus on lower fat intakes and higher physical activity to prevent the transition to MUO.

The Relationship of Circulating Homocysteine with Fibrinogen, Blood Pressure, and Other Cardiovascular Measures in African Adolescents.

OBJECTIVES: To evaluate the associations between homocysteine (Hcy) and cardiovascular health in South African adolescents. STUDY DESIGN: Circulating Hcy concentrations of 172 South African adolescents (105 girls, ages 13 to <18 years) were measured. Anthropometric and cardiovascular factors were also included and cross-sectionally analyzed through general linear models. RESULTS: Hcy correlated positively with body weight (P = .03; after adjusting for multiple testing, it was not regarded as significant) and muscle mass (P = .01), but negatively with fibrinogen concentrations (P = .001). Across Hcy tertiles, blood pressure produced approximating U-shaped curves, with differences between the middle and upper tertiles (all P < .02). Forty percent of the adolescents had elevated blood pressure, of whom 37% fell in the lowest and 38% in the highest Hcy tertiles. Hcy differed between the sexes (with boys having higher Hcy), but not between subgroups based on puberty, weight, stunting, smoking, or alcohol consumption. CONCLUSIONS: Both high and low Hcy could be early contributing risk factors to cardiovascular health. The associations between Hcy and blood pressure suggest that dietary and lifestyle manipulation, to achieve the optimal range of Hcy, may be beneficial in preventing Hcy-related hypertension in adulthood. The inverse relationship between Hcy and fibrinogen remains to be clarified.

Erratum: Level of agreement between objectively determined body composition and perceived body image in 6- to 8-year-old South African children: The Body Composition-Isotope Technique study.

[This corrects the article DOI: 10.1371/journal.pone.0237399.].

Exclusive Breastfeeding, Child Mortality, and Economic Cost in Sub-Saharan Africa.

BACKGROUND: Sub-Saharan Africa remains the region with the highest under-5 mortality (U5M) rates globally. Emerging evidence revealed that exclusive breastfeeding (EBF) rates are significantly associated with a decreased risk for child mortality. Our aim with this study is to fill the gap of knowledge regarding the economic impact of EBF practices in relation to U5M in sub-Saharan African countries. METHODS: Data were gathered from the World Bank's database during the period 2000-2018. A meta-analytical approach was used to evaluate heterogeneity of country estimates and to perform an estimate of the prevalence of EBF and economic cost by country. The association between estimates of U5M and EBF prevalence was estimated and used to perform the total cumulative nonhealth gross domestic product loss (TCNHGDPL) attributable to U5M in 2018 and 2030. RESULTS: The prevalence of EBF increased by 1%, and U5M reduced significantly by 3.4 per 1000 children each year during 2000-2018. A U5M reduction of 5.6 per 1000 children could be expected if EBF prevalence improved by 10%. The TCNHGDPL in sub-Saharan Africa had a total value higher than $29 billion in 2018. The cost of U5M is estimated to increase to ∼$42 billion in 2030. CONCLUSIONS: If EBF prevalence improve by 10%, the related TCNHGDPL was estimated to be $27 billion in 2018 and $41 billion in 2030, therefore saving ∼$1 billion. Sub-Saharan Africa should imperatively prioritize and invest in essential approaches toward EBF implementation.

Effects and Reversibility of Pre- and Post-natal Iron and Omega-3 Fatty Acid Deficiency, Alone and in Combination, on Bone Development in Rats.

Both iron and omega-3 (n-3) polyunsaturated fatty acids may play an important role in bone development. The aim of this study was to investigate the effects of pre- and post-natal iron and n-3 fatty acid deficiency (FAD), alone and in combination, on bone development in rats, and to determine whether effects are reversible when a sufficient diet is provided post-weaning. Using a 2×2-factorial design, 56 female Wistar rats were allocated to one of four diets: (1) control, (2) iron deficient (ID), (3) n-3 FAD or (4) ID and n-3 FAD, and were maintained on the respective diets throughout gestation and lactation. At weaning (post-natal day [PND] 21), offspring (n = 24/group; male:female=1:1) were randomly allocated to either continue with their respective diets or to switch to the control diet until PND 42-45. Bone mineral density (BMD) and bone strength were determined using dual X-ray absorptiometry and three-point bending tests, respectively. Pre- and post-natal ID resulted in significantly lower BMD in the spine and bone strength in the left femur. Both ID and n-3 FAD resulted in lower BMD in the right femur, with an additive reduction in the combined ID and n-3 FAD group vs. controls. While negative effects of pre- and post-natal ID alone were reversed in offspring switched to a control diet post-weaning, lower BMD and bone strength persisted in offspring with combined ID and n-3 FAD during the prenatal and early post-natal period. Effects were not sex-specific. These results indicate that ID during early life may negatively influence bone development, with potential additive effects of n-3 FAD. While the effects of ID alone seem reversible, a combined ID and n-3 FAD may result in irreversible deficits in bone development.

Psychosocial barriers and enablers of exclusive breastfeeding: lived experiences of mothers in low-income townships, North West Province, South Africa.

BACKGROUND: Despite national efforts to promote exclusive breastfeeding (EBF), South Africa's EBF rate is only 32 %. The aim of this study was to examine the rate of EBF discontinuation and the lived experiences of breastfeeding mothers at postnatal time points 3-14 days, 4-8 weeks, 10-14 weeks and 20-24 weeks. METHODS: This community-based mixed-methods study collected data within a prospective cohort study on sociodemographics, the Edinburgh Postnatal Depression Scale (EPDS) and the Breastfeeding Self-Efficacy Scale-Short Form (BSES-SF) at 6-8 weeks with infant feeding data collected at 4-8, 10-14 and 20-24 weeks from 159 mothers living in low income areas. Six focus groups with 32 mothers with infants aged 6-24 weeks were conducted. Descriptive statistics was used for the quantitative data and thematic analysis for qualitative data. RESULTS: The majority of mothers were unmarried (84.9%), living with family (69.2%) and unemployed (74.2%). Exclusive breastfeeding decreased from 34% at 4-8 weeks to 9.7% at 20-24 weeks. Mixed feeding with infant formula increased from 17.0 to 30.6% and food feeding from 3.1 to 54.2%. While there were no statistically significant associations between EBF and any of the quantitative sociodemographic variables, in the qualitative data, codes associated with barriers were more than enablers. The themes were Mothers' attributes (wellbeing, experiences and relationships) with the code mother's stress the strongest barrier, Mother's knowledge, attitudes and practices of breastfeeding with the code conventional medicines the strongest barrier, Family environment with the code home setting the strongest barrier, Social environment with public spaces and places a barrier and in Baby cues the code baby stomach ailments the barrier. Within these same themes mother's positive emotions, benefits of breastfeeding, support in the home, access to information and services from health professionals and baby's health were strong enabling factors. CONCLUSIONS: Low EBF, high mixed feeding and a high EPDS score were explained by the barriers identified in the qualitative data. The data suggests that mothers from low-income households would be better supported through interventions that address food insecurity; family relationships and those that build confidence in mothers and resilience in confronting difficult and hostile breastfeeding environments.