Differential associations between kidney and vascular health biomarkers in young adults stratified by blood pressure status: The African Prospective study on the Early Detection and Identification of Cardiovascular disease and Hypertension study.

OBJECTIVE

Hypertension and kidney disease share common pathophysiological pathways involved in endothelial dysfunction including increased oxidative stress and chronic inflammation. The precise early-stage mechanisms associated with nephron-specific kidney injury remain unclear. We aimed to explore associations of kidney function biomarkers with markers representing these mechanisms in young adults stratified by blood pressure status [according to 2018 European Society of Cardiology (ESC)/European Society of Hypertension (ESH) guidelines].

METHODS

We cross-sectionally analysed 1055 adults. Kidney biomarkers included estimated glomerular filtration rate (eGFR), urinary albumin-to-creatinine ratio (uACR), alpha-1 microglobulin (uA1M), neutrophil gelatinase-associated lipocalin (uNGAL), uromodulin (uUMOD) and CKD273 classifier. Markers of oxidative stress [gamma-glutamyl transferase (GGT); malondialdehyde (MDA)], inflammation [interleukin 6 (IL-6); C-reactive protein (CRP); fibrinogen] and endothelial function [soluble intercellular adhesion molecule-1; soluble vascular cell adhesion molecule-1 (sVCAM-1); von Willebrand factor antigen (vWF ag ); monocyte chemoattractant protein-1 (MCP-1); plasminogen activator inhibitor-1 activity (PAI-1 act ); urinary nitrate-to-nitrite ratio] were analysed.

RESULTS

Individuals in the hypertensive group (mean age 24.8 years; 73.2% men; 39% Black) had higher GGT, CRP, IL-6, MCP-1 and PAI-1 act levels (all P  ≤ 0.024) compared to their normotensive counterparts. In individuals with hypertension, eGFR associated negatively and uNGAL positively with IL-6, while uA1M associated positively with PAI-1 act (all P  ≤ 0.047). In the same group, UMOD associated positively with fibrinogen and CKD273 classifier negatively with MCP-1 (all P  ≤ 0.021). In contrast, eGFR associated positively with MDA and negatively with GGT, CKD273 classifier associated positively with GGT, sVCAM-1 and vWF ag , and uACR associated negatively with CRP (all P  ≤ 0.033) in normotensives.

CONCLUSION

In young adults, mechanisms linked to early nephron-specific kidney injury biomarkers differ according to blood pressure status.