A comparison of paediatric hypertension clinical practice guidelines and their ability to predict adult hypertension in an African birth cohort.

It remains unclear which paediatric hypertension clinical practice guideline (CPG) should be applied in an African population. We, therefore, aimed to compare commonly used CPG (2017 AAP, 2016 ESH, 2004 Fourth Report) developed in high-income countries for use in South African children at four paediatric ages (children: 5 years, 8 years; adolescents: 13 years, 17 years) to determine which best predicts elevated blood pressure (BP) in adulthood (22 years, 28 years). Moreover, the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for each specific paediatric CPG was calculated across the age points. The 2017 AAP definition identified more children and adolescents with hypertension when compared to the 2004 Fourth Report and 2016 ESH guidelines. In computed hazards ratios, ages 8 years to 17 years, all three paediatric CPG significantly predicted the risk of elevated BP in young adulthood (p ≤ 0.032). However, sensitivity to predict elevated BP at age 22 years for all CPG was generally low (17.0%-33.0%) with higher specificity (87.4%-93.1%). Sensitivity increased at age 28 years (51.4%-70.1%), while specificity decreased (52.8%-65.1%). Both PPV and NPV at both adult age points varied widely (17.9%-79.9% and 29.3%-92.5% respectively). The performance of these paediatric CPG in terms of AUC were not optimal at both adult age points, however, the 2017 AAP definition at age 17 years met an acceptable level of performance (AUC = 0.71). Our results, therefore, highlight the need for more research to examine if an African-specific CPG would better identify high-risk children to minimise their trajectory towards adult hypertension.

Pilot implementation of Bukhali: A preconception health trial in South Africa.

OBJECTIVES: This article describes the learnings from the pilot phase of the Healthy Life Trajectories Initiative, a preconception health trial for 18- to 25-year-old women in Soweto, South Africa. METHODS: The study compares two arms focussed on either physical and mental health (intervention; delivered by community health workers - 'Health Helpers') or standard of care plus (control; standard access to healthcare plus additional telephonic input on 'life skills'; delivered by call centre assistants). These are collectively referred to as Bukhali. Data on the pilot implementation of the Bukhali trial (n = 1655) were collected from (1) weekly team meetings, (2) two focus groups (one with the intervention team Health Helpers, n = 7; one with intervention participants, n = 8) and one paired interview with control call centre assistants (n = 2), (3) notes from eight debrief sessions with Health Helpers and (4) quantitative trial monitoring data. Qualitative data were thematically analysed. RESULTS: The findings clustered within three themes: (1) challenges for young women in Soweto, (2) priorities for young women in Soweto and (3) implementation challenges and perceptions of the intervention. Challenges were mostly related to tough socioeconomic circumstances and less prioritisation of living a healthier life. The priorities of employment and educational opportunities reflected the socioeconomic challenges, where health was not recognised as priority. The main challenge to participation and compliance with the trial was that young women in Soweto generally wanted a tangible and preferably financial and immediate benefit. Community peer sessions, despite being recommended by young women as part of the intervention development, were not successful. Many women also moved between multiple households within Soweto, which flagged concerns for a cluster trial and risk of contamination. CONCLUSION: Preconception health trials should consider socioeconomic challenges present in urban poor contexts. Learnings from the pilot phase significantly affected the design and implementation of the main Bukhali trial.

Urban young women's preferences for intervention strategies to promote physical and mental health preconception: A Healthy Life Trajectories Initiative (HeLTI).

This study aimed to qualitatively investigate young women's preferences for preconception intervention strategies to promote physical and mental health in a rapidly transitioning, urban setting. Four semi-structured focus group discussions were conducted with young women (n = 29, 18-24 years old) from Soweto, South Africa. Qualitative data were thematically analysed. Two main themes were identified: 1) challenges and needs of intervention beneficiaries; and 2) preferences for intervention strategies (content and delivery). The challenges participants mentioned could be classified as those relating to social pressure, identity, and socioeconomic circumstances. Mental health support appeared to be a greater need than physical health, and this featured in their preferences for intervention content, although a number of physical health topics were also mentioned (healthy eating and contraception). Participants had mixed preferences for intervention materials, ranging from printed to electronic and mobile resources. Their preferences for intervention activities ranged from educational sessions, to fun and interactive practical activities, and activities they could take home. Community health workers (CHWs) were the preferred agent of delivery for interventions, though participants emphasised the importance of CHWs having appropriate interpersonal skills and own life experience. Some women preferred one-on-one sessions with a CHW, while others preferred group sessions. While recognising the value of family sessions, young women were less enthusiastic about this approach. These findings provide valuable formative data for developing effective interventions to optimise young women's preconception health in urban Africa. These contextual realities should be acknowledged when addressing key physical and mental health issues facing young women.

Associations between dietary salt, potassium and blood pressure in South African adults: WHO SAGE Wave 2 Salt & Tobacco.

BACKGROUND & AIMS: In June 2016, South Africa implemented legislation mandating maximum sodium levels in a range of processed foods with a goal of reducing population salt intake and disease burden from hypertension. Our aim was to explore the relationship between salt and blood pressure (BP) in a subsample of the World Health Organization Study on global AGEing and adult health (SAGE) Wave 2 before implementation of legislation in South Africa. METHODS & RESULTS: Blood pressure (BP) was measured in triplicate (n = 2722; median age 56 years; 33% male) and 24-h urine collected in a nested subsample (n = 526) for sodium, potassium and creatinine analysis. Hypertension prevalence was 55% in older adults (50-plus years) and 28% in younger adults (18-49 years). Median salt intake (6.8 g/day) was higher in younger than older adults (8.6 g vs 6.1 g/day; p < 0.001), and in urban compared to rural populations (7.0 g vs 6.0 g/day; p = 0.033). Overall, 69% of participants had salt intakes above 5 g/day. Potassium intakes were generally low (median 35 mmol/day) with significantly lower intakes in rural areas and older adults. Overall, 91% of adults failed to meet the daily potassium recommendation of 90 mmol/d. Salt intakes above 5 g/day, and to a greater extent, a dietary sodium-to-potassium (Na:K) ratio above 2 mmol/mmol, were associated with significantly steeper regression slopes of BP with age. CONCLUSION: These preliminary results indicate that high dietary Na:K ratio may lead to a greater increase in BP and hypertension risk with age. Interventions to increase potassium intakes alongside sodium reduction initiatives may be warranted.

Recent advances in understanding hypertension development in sub-Saharan Africa.

Consistent reports indicate that hypertension is a particularly common finding in black populations. Hypertension occurs at younger ages and is often more severe in terms of blood pressure levels and organ damage than in whites, resulting in a higher incidence of cardiovascular disease and mortality. This review provides an outline of recent advances in the pathophysiological understanding of blood pressure elevation and the consequences thereof in black populations in Africa. This is set against the backdrop of populations undergoing demanding and rapid demographic transition, where infection with the human immunodeficiency virus predominates, and where under and over-nutrition coexist. Collectively, recent findings from Africa illustrate an increased lifetime risk to hypertension from foetal life onwards. From young ages black populations display early endothelial dysfunction, increased vascular tone and reactivity, microvascular structural adaptions as well as increased aortic stiffness resulting in elevated central and brachial blood pressures during the day and night, when compared to whites. Together with knowledge on the contributions of sympathetic activation and abnormal renal sodium handling, these pathophysiological adaptations result in subclinical and clinical organ damage at younger ages. This overall enhanced understanding on the determinants of blood pressure elevation in blacks encourages (a) novel approaches to assess and manage hypertension in Africa better, (b) further scientific discovery to develop more effective prevention and treatment strategies and

Leptin is positively associated with blood pressure in african men with a low body mass index: the SAfrEIC study.

Severe underweight may be a risk factor for hypertension in developing countries, although the manner whereby this occurs is unknown. Leptin is known to exert both beneficial and detrimental vascular effects, and is predictive of poor cardiovascular outcome at high levels, but also at low levels. We explored the relationship between blood pressure and leptin in black men from South Africa with a body mass index (BMI) in the underweight to normal range. We included 113 African men (BMI≤25 kg/m(2)) and took anthropometric, biochemical and cardiovascular measures. The blood pressure-leptin relationship was then investigated along quintiles of leptin and within BMI stratified median split (20 kg/m(2)) groups. Blood pressure increased across leptin quintiles 1-3 (p for trend≤0.040), whereas no relationship was observed along quintiles 3 to 5 (p for trend≥0.14) (adjusted for age and waist circumference). Blood pressure was similar in the two BMI median split groups (p≥0.083). In the low BMI group only, blood pressure associated positively with leptin following unadjusted, partial, and full adjustment (systolic blood pressure and diastolic blood pressure: R(2)=0.20-0.27, ß=0.32-0.34, p≤0.009). Decreasing leptin levels are not likely to contribute to hypertension prevalence in the underweight. Rather, in African men with a BMI≤20 kg/m(2), low leptin levels are positively and independently associated with elevated blood pressure, which is not seen at higher BMI (20-25 kg/m(2)). Our findings suggest a differential concentration dependent vascular effect of leptin in underweight and normal weight African men.

Evaluation of waist-to-height ratio to predict 5 year cardiometabolic risk in sub-Saharan African adults.

BACKGROUND AND AIMS: Simple, low-cost central obesity measures may help identify individuals with increased cardiometabolic disease risk, although it is unclear which measures perform best in African adults. We aimed to: 1) cross-sectionally compare the accuracy of existing waist-to-height ratio (WHtR) and waist circumference (WC) thresholds to identify individuals with hypertension, pre-diabetes, or dyslipidaemia; 2) identify optimal WC and WHtR thresholds to detect CVD risk in this African population; and 3) assess which measure best predicts 5-year CVD risk. METHODS AND RESULTS: Black South Africans (577 men, 942 women, aged >30years) were recruited by random household selection from four North West Province communities. Demographic and anthropometric measures were taken. Recommended diagnostic thresholds (WC > 80 cm for women, >94 cm for men; WHtR > 0.5) were evaluated to predict blood pressure, fasting blood glucose, lipids, and glycated haemoglobin measured at baseline and 5 year follow up. Women were significantly more overweight than men at baseline (mean body mass index (BMI) women 27.3 ± 7.4 kg/m(2), men 20.9 ± 4.3 kg/m(2)); median WC women 81.9 cm (interquartile range 61-103), men 74.7 cm (63-87 cm), all P < 0.001). In women, both WC and WHtR significantly predicted all cardiometabolic risk factors after 5 years. In men, even after adjusting WC threshold based on ROC analysis, WHtR better predicted overall 5-year risk. Neither measure predicted hypertension in men. CONCLUSIONS: The WHtR threshold of >0.5 appears to be more consistently supported and may provide a better predictor of future cardiometabolic risk in sub-Saharan Africa.