Elevated blood pressure positively associates with alpha-1 microglobulin in prepubescent children: the ExAMIN Youth SA study

The relationship between kidney function and the soluble (pro)renin receptor in young adults: the African-PREDICT study

High renin angiotensin-aldosterone system (RAAS) activity is associated with target organ damage. Soluble (pro)renin receptor [s(P)RR] forms part of the RAAS cascade and is associated with kidney damage through both angiotensin II-dependent and -independent pathways. Additionally, s(P)RR levels are higher in hypertension and chronic kidney disease (CKD) patients. However, little is known regarding ethnic and sex differences in s(P)RR levels and its potential associations with kidney function in young healthy adults. Identifying these associations in young populations is essential for identification of areas of intervention to prevent CKD. This study aimed to compare levels of s(P)RR across ethnic and sex groups and determine s(P)RR associations with markers of kidney function, including estimated glomerular filtration rate (eGFR), urine albumin-to-creatinine ratio (uACR) and alpha 1-microglobulin (uA1M). The study included 1156 young healthy Black and White South Africans aged 20-30 years (Men, N = 555; Women, N = 601). We measured uA1M, albumin and creatinine in urine to calculate uACR. s(P)RR, cystatin C and creatinine were measured in serum and eGFR was calculated. Independent t-tests and multiple regression analyses were carried out to compare groups and explore associations. s(P)RR levels were higher in White participants, and higher in White men than in women (all p < 0.001). eGFR was higher in both Black men and women than in White men and women (both p ≤ 0.001). Both uA1M and uACR were higher in Black men than in White men (both p ≤ 0.003). We observed an independent negative association between eGFR and s(P)RR in Black women only (Adj.R2 = 0.309; Std. β=-0.141; p = 0.026), while uA1M associated positively with s(P)RR in the White group only (Adj.R2 = 0.063; Std. β = 0.115; p = 0.018). No associations were evident between uACR and s(P)RR in any of the groups. The positive association between uA1M and s(P)RR suggest that s(P)RR may contribute to kidney damage in young White participants through pathways associated with inflammation and fibrosis. A better understanding of mechanisms linking s(P)RR to kidney damage may lead to discovery of areas of therapeutic interventions for the prevention and treatment of CKD in different population groups. Trial registration ClinicalTrials.gov NCT03292094. Registration date 2017-09-12.

Urinary Biomarkers Of Kidney Function As Predictors Of Cardiovascular Health: A Systematic Review

PURPOSE OF REVIEW

The growing burden of cardiovascular diseases has become a significant concern in both adult and youth populations. Urinary biomarkers of kidney function could provide useful insights that may aid in the early identification of individuals at higher risk of adverse cardiovascular outcomes. This systematic review aimed to assess associations between urinary biomarkers of kidney function and different measures of cardiovascular health.

RECENT FINDINGS

PubMed, Scopus, and EBSCOhost were searched for articles published between January 2018 and December 2023. Studies exploring associations between urinary kidney biomarkers (alpha-1 microglobulin (uA1M), neutrophil gelatinase-associated lipocalin (uNGAL), uromodulin (uUMOD) and CKD273 classifier) and measures of cardiovascular health (blood pressure and markers of target organ damage) were included. We identified 1186 articles, with 22 studies eligible for inclusion. Among 12 studies reporting associations between uA1M and measures of cardiovascular health, six studies indicated positive associations with office blood pressure and three studies observed associations with different markers of target organ damage. Out of the nine studies that explored the link between uUMOD and cardiovascular health parameters, four found negative associations between uUMOD and blood pressure. With regard to uNGAL, only two out of the seven studies analysed reported varying associations with blood pressure, while neither of the two studies focusing on CKD273 observed any statistically significant results. Biomarkers of kidney tubule function, represented by uA1M and uUMOD, are relevant in the setting of cardiovascular health and should be assessed for utilisation in clinical practice to identify adverse cardiovascular outcomes at an early stage allowing for timely intervention.

Hypertension in sub-Saharan Africa: the current profile, recent advances, gaps, and priorities

Recent global and regional reports consistently confirm the high and increasing prevalence of hypertension in sub-Saharan Africa (SSA), with poor detection, treatment, and control rates. This narrative review summarises the burden of hypertension in SSA and recent findings from community-based hypertension management strategies. We further outline prominent risk factors according to recent data and associated underlying mechanisms for hypertension development. An extensive review of literature showed that most countries have reported on the prevalence of hypertension during 2017-2023, despite limitations linked to the lack of nationally representative studies, heterogeneity of sampling and data collection methods. Task-shifting approaches that assign roles to model patients and community health workers reported improved linkage to healthcare services and adherence to medication, with inconsistent findings on blood pressure (BP)-lowering effects over time. The regularly reported risk factors include unhealthy diet, sedentary lifestyle, increased adiposity and underweight, ageing, level of education, and/or income as well as psychosocial factors. Newer data on the pathophysiological mechanisms leading to hypertension and potential areas of intervention are reported from children and adults and include, among others, salt-handling and volume overload, endothelial function, BP dipping patterns and the role of human immunodeficiency virus . To conclude, significant strides have been made in data reporting from SSA on the burden of hypertension in the region as well as biomarker research to improve understanding and identification of areas of intervention. However, gaps remain on linkage between knowledge generation, translation, and implementation research. Coordinated studies addressing both discovery science and public health are crucial to curb hypertension development and improve management in SSA.

Phenotyping Kidney Function in Young Adults With High Blood Pressure: The African-PREDICT Study

Biomarkers of kidney function, including glomerular, tubular, and fibrotic markers, have been associated with blood pressure in elderly populations and individuals with kidney and cardiovascular diseases. However, limited information is available in young adults. In this study, we compared levels of several kidney function biomarkers between normotensive and hypertensive young adults and explored the associations of these biomarkers with blood pressure within these groups. In this cross-sectional assessment, twenty-four-hour (24-h) blood pressure measurements of 1055 participants (mean age = 24.6 years) were used to classify hypertension as per the 2018 ESC/ESH guidelines. Biomarkers of kidney function included estimated glomerular filtration rate, urinary albumin, alpha-1 microglobulin (uA1M), neutrophil gelatinase-associated lipocalin (uNGAL), uromodulin (uUMOD), and the CKD273 classifier. All urinary biomarkers, except for the CKD273 classifier, were standardized for urinary creatinine (Cr). In the hypertensive group (61.0% White; 73.2% men), urinary albumin-to-creatinine ratio (uACR), uNGAL/Cr and uUMOD/Cr were lower than the normotensive group. In multiple regression analyses, 24-h systolic blood pressure (SBP) (β = 0.14; p = 0.042), 24-h diastolic blood pressure (DBP) (β = 0.14; p = 0.040), and 24-h mean arterial pressure (MAP) (β = 0.16; p = 0.020) associated positively with uA1M/Cr in the hypertensive group, while 24-h MAP positively associated with uACR (β = 0.17; p = 0.017). In exploratory factor analysis, positive associations of 24-h DBP and 24-h MAP with a factor pattern including tubular biomarkers were observed in the hypertensive group (24-h DBP: β = 0.18; p = 0.026, 24-h MAP: β = 0.17; p = 0.032). In the setting of hypertension, high perfusion pressure in the kidneys may play a role in the development of proximal tubule damage and promote early deterioration in kidney function in young adults. Trial Registration: ClinicalTrials.gov identifier: NCT03292094.