Cumulative Blood Pressure Load and Incident CKD

Rationale & ObjectiveThe association of long-term cumulative blood pressure (BP) loads with the risk of incident chronic kidney disease (CKD) remains a matter of debate. This study aimed to investigate this association among healthy Korean adults with normal kidney function.Study DesignProspective cohort study.Setting & ParticipantsWe analyzed 5,221 participants without CKD in the Korean Genome and Epidemiology Study. Cumulative systolic and diastolic BP (SBP and DBP) loads were calculated as the ratios of the areas under the curve (AUC) for SBP ≥120 mmHg or ≥80 mmHg for DBP divided by the AUC for all SBP or DBP measurements during the exposure period. These AUCs were categorized into four groups: group 0 (reference), cumulative BP load of 0 and groups 1-3, tertiles of cumulative BP loads.OutcomePrimary endpoint was incident CKD defined as a composite of an estimated glomerular filtration rate (eGFR) below 60 mL/min/1.73 m2 or proteinuria greater than 1+ on dipstick examination for at least two consecutive measurements ≥90 days apart.Analytical ApproachMultivariable Cox proportional hazards regression to estimate the independent association of cumulative BP loads with incident CKD.ResultsHigher cumulative SBP and DBP loads were associated with an increased risk of incident CKD (hazard ratio [HR] 1.23, 95% confidence interval [CI] 1.12-1.35 for SBP and HR 1.14, 95% CI 1.04-1.26 for DBP loads for each 1.0 unit greater load). Compared to SBP group 0, groups 2 and 3 were associated with 1.94- and 1.89-fold greater risk of incident CKD. Compared to DBP group 0, groups 2 and 3 were associated with 1.42- and 1.54-fold greater risks. These associations of high cumulative BP loads with an increased risk of incident CKD remained consistent even in subgroups not taking antihypertensive agents or without prior hypertension diagnosis.LimitationsThe assessment of CKD outcomes relied on eGFR and spot urine tests.ConclusionsThese findings highlight the association between high cumulative SBP and DBP loads and the occurrence of CKD, even in individuals with normal BP levels.