Prognostic value of kidney function biomarkers for target organ injury in young adults stratified by blood pressure status: the African-PREDICT study.

BACKGROUND AND AIMS: Kidney function biomarkers are valuable early risk predictors for target organ injury (TOI), yet their prognostic value remains underexplored in young hypertensive adults. We aimed to determine whether baseline kidney biomarkers could predict TOI over 4.8-years in young adults, stratified by follow-up blood pressure status.

METHODS AND RESULTS: In this prospective study (N = 561 adults aged 20-30 years at baseline), baseline 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. Cox regression assessed the prognostic value of kidney biomarkers for increased TOI [including pulse wave velocity (PWV) carotid intima-media thickness (cIMT), left ventricular mass index (LVMi) and relative wall thickness (RWT)] at follow-up. In the normotensive, incident and sustained hypertensive groups, PWV, cIMT, LVMi and RWT increased from baseline to follow-up (all p ≤ 0.033). In normotensives, higher levels of tubular biomarkers (uNGAL and uA1M) were associated with a lower risk of increased cIMT and LVMi, while higher eGFR and lower uA1M were associated with increased RWT (all p ≤ 0.026). In individuals who developed hypertension, lower eGFR predicted higher PWV and LVMi, while higher uACR and CKD273 scores were associated with increased RWT (all p ≤ 0.026). In the sustained hypertensives, lower uUMOD and CKD273 scores predicted increased cIMT, whereas higher eGFR was associated with increased RWT (all p ≤ 0.039).

CONCLUSION: Kidney biomarkers, even within normal ranges, are associated with early cardiovascular changes in young adults and these relationships are strongly modified by blood pressure status.