Obesity and salt intake are both established factors contributing to cardiovascular disease development. Recently, studies found a controversial positive relationship between dietary salt and obesity. Therefore, the authors investigated whether obesity-related measures are associated with 24-hour urinary sodium in a healthy biethnic population. The study included 761 adults (20-30 years) with complete 24-hour urinary sodium, anthropometry, and bioelectrical impedance measurements. In single regression analyses all obesity-related measures related positively with 24-hour urinary sodium (P ≤ .008). However, with multivariate adjustments for energy intake, accelerometery, age, sex, black and white ethnicity, and other covariates, only body surface area (BSA) remained independently associated with 24-hour urinary sodium (R 2 = 0.72, β = .05, P = .039). To conclude, we found a consistent and robust positive relationship between BSA and estimated salt intake -but not with traditional obesity measures such as body mass index (BMI). Further studies are needed to investigate body surface area and potentially, skin area, in salt handling.

Background The burden of cardiovascular disease (CVD) and hypertension is rapidly increasing in low- and middle-income countries. This is evident not only in adults, but also in children. Recent estimates of prevalence in children are lacking, particularly in Africa. As such, we conducted a systematic review and meta-analysis to provide updated estimates of paediatric hypertension in Africa. Methods We searched PubMed and EBSCO to identify articles published from January 2017 to November 2020. Studies were assessed for quality. We combined results for meta-analyses using a random effects model (Freeman-Tukey arcsine transformation). Heterogeneity was quantified using the I 2 statistic. Findings In the narrative synthesis of 53 studies, publication bias was low for 28, moderate for 24, and high for one study. Hypertension prevalence ranged substantially (0·2%-38·9%). Meta-analysis included 41 studies resulting in data on 52918 participants aged 3 to 19 years from ten countries. The pooled prevalence for hypertension (systolic/diastolic BP≥95th percentile) was 7·45% (95%CI 5·30-9·92, I 2 =98.96%), elevated blood pressure (BP, systolic/diastolic BP≥90th percentile and <95th percentile) 11·38% (95%CI 7·94-15·33, I 2 =98.97%) and combined hypertension/elevated BP 21·74% (95%CI 15·5-28·69, I 2 =99.48%). Participants categorized as overweight/with obesity had a higher prevalence of hypertension (18·5% [95%CI 10·2-28·5]) than those categorized as underweight/normal (1·0% [95%CI 0·1-2·6], 4·8% [95%CI 2·9-7·1], p<0·001). There were significant differences in hypertension prevalence when comparing BP measurement methods and classification guidelines. Interpretation Compared to a previous systematic review conducted in 2017, this study suggests a continued increase in prevalence of paediatric hypertension in Africa, and highlights the potential role of increasing overweight/obesity. Funding This research was funded in part by the Wellcome Trust [Grant number:214082/Z/18/Z]. LJW and SAN are supported by the DSI-NRF Centre of Human Development at the University of the Witwatersrand.

Objective: Inflammatory mediators have been implicated in the early stages of cardiovascular disease development, including hypertension. Since global reports reflect a higher hypertension prevalence in black than white populations, we hypothesise the involvement of specific inflammatory mediators. We therefore compared a detailed range of 22 inflammatory mediators between young black and white adults, and determined the relationship with blood pressure. Approach and Results: We included 1197 adults (20-30 years; 50% black; 52% female) with detailed ambulatory blood pressures. Blood samples were analysed for 22 inflammatory mediators. For pro-inflammatory mediators, the black adults had higher C-reactive protein, interferon-inducible T-cell alpha chemoattractant, macrophage inflammatory protein 3 alpha (all p≤0.008), but lower interferon-gamma, interleukin (IL)-1β, IL-8, IL-12, IL-17A, and tumour necrosis factor alpha (all p≤0.048). For anti-inflammatory mediators the black group consistently had lower levels (IL-5, IL-10 and IL-13 (all p≤0.012)), resulting in generally higher pro-to-anti-inflammatory ratios in black than white adults (p≤0.001). In mediators with proand anti-inflammatory functions, the black group had lower granulocyte-macrophage colony-stimulating factor and IL-6 (both p≤0.010). These patterns were confirmed after adjustment for age, sex and waist circumference, or when stratifying by hypertensive status, sex and socioeconomic status. Multi-variable adjusted regression analyses and factor analysis yielded no relationship between inflammatory mediators and blood pressure in this young healthy population. Conclusions: Black and white ethnic groups each consistently presented with unique inflammatory mediator patterns regardless of blood pressure, sex or social class. No association with blood pressure was seen in either of the groups.

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Background The role of inflammation in the development of hypertension remains incompletely understood. While single inflammatory mediators have been shown to associate with changes in blood pressure (ΔBP), the role of clusters of inflammatory mediators has been less comprehensively explored. We therefore determined whether individual or clusters of inflammatory mediators from a large biomarker panel were associated with ΔBP over 4.5 years, in young healthy adults. Methods We included 358 adults (white, n = 156; black, n = 202) with detailed information on ambulatory blood pressure (BP) at baseline and follow-up. Baseline blood samples were analysed for 22 inflammatory mediators using multiplexing technology. Principal component analysis was used to study associations between clusters of inflammatory mediators and ΔBP. Results In the total cohort in multivariable-adjusted regression analyses, percentage change in 24hr systolic BP associated positively with Factors 1 (Interferon-gamma, interleukin (IL)-4, IL-7, IL-10, IL-12, IL-17A, IL-21, IL-23, macrophage inflammatory protein (MIP)-1α, MIP-1β, TNF-α, granulocyte-macrophage colony-stimulating factor (GM-CSF)) and 2 (IL-5, IL-6, IL-8, IL-13). Change in daytime systolic BP associated positively with Factors 1, 2 and 3 (C-Reactive protein, IL-1β, IL-2, MIP-3α). Subgroup analysis found these findings were limited to white study participants. Numerous associations were present between individual inflammatory mediators (Interferon-gamma, GM-CSF, IL-4, IL-6, IL-7, IL-8, IL-10, IL-12, IL-13, IL-17A, IL-21, IL-23, MIP-1α and MIP-1β) and ΔBP in the white but not black subgroups. Conclusion We found independent relationships between numerous inflammatory mediators (individual and clusters) and ΔBP over 4.5 years. The relationship between inflammatory markers and ΔBP was only found in white participants. ClinicalTrials.gov (Identifier: NCT03292094)..

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Purpose Low-grade inflammation and a diet high in salt are both established risk factors for cardiovascular disease. High potassium (K +) intake was found to counter increase in blood pressure due to high salt intake and may potentially also have protective anti-inflammatory effects. To better understand these interactions under normal physiological conditions, we investigated the relationships between 22 inflammatory mediators with 24-h urinary K + in young healthy adults stratified by low, medium and high salt intake (salt tertiles). We stratified by ethnicity due to potential salt sensitivity in black populations. Methods In 991 healthy black (N = 457) and white (N = 534) adults, aged 20-30 years, with complete data for 24-h urinary sodium and K + , we analysed blood samples for 22 inflammatory mediators. Results We found no differences in inflammatory mediators between low-, mid-and high-sodium tertiles in either the black or white groups. In multivariable-adjusted regression analyses in white adults, we found only in the lowest salt tertile that K + associated negatively with pro-inflammatory mediators, namely interferon gamma, interleukin (IL)-7, IL-12, IL-17A, IL-23 and tumour necrosis factor alpha (all p ≤ 0.046). In the black population, we found no independent associations between K + and any inflammatory mediator. Conclusion In healthy white adults, 24-h urinary K + associated independently and negatively with specific pro-inflammatory mediators, but only in those with a daily salt intake less than 6.31 g, suggesting K + to play a protective, anti-inflammatory role in a low-sodium environment. No similar associations were found in young healthy black adults.

A major obstacle to tackling the growing burden of chronic disease in South Africa is lack of testing, particularly where individuals face multiple barriers to accessing health services. We conducted a pilot study to evaluate a cardiometabolic self-measurement kit, including assessment of blood pressure, obesity and urine analysis, amongst adults in Soweto, South Africa. Participants (N = 94) were recruited by researchers during community health screening and were provided with a home test kit including a tablet with self-measurement instructions. The participants entered their results on the tablet and, on completion, the researcher immediately repeated the measurements. We interviewed 10% of participants to understand their experience and views of the kits. Concordance correlation coefficients ranged from 0.78 for waist circumference to 0.93 for height, while the overall percentage agreement ranged from 80.5% for both urine protein and urine glucose testing to 91.4% for the identification of central obesity (ratio of waist circumference to height of ≥ 0.5). Participants saw the need for self-testing and found the process for the most part simple, though urine testing and height self-assessment presented some challenges. This pilot study suggests that self-assessment at home has the potential to facilitate the identification of individuals at risk for cardiometabolic disease in low-income settings, adding to a growing body of evidence on the use of self-testing in disease prevention and detection. However, we would not recommend self-testing for urine glucose and protein without further study.