24-hour diastolic BP variability linked to renal decline in diabetic kidney disease

ObjectiveDiabetic kidney disease (DKD) is the leading cause of end-stage renal disease (ESRD) worldwide. Blood pressure variability (BPV), especially diastolic BPV (DBPV), is closely linked to renal microcirculation but remains understudied in DKD. This study aimed to evaluate the association of DBPV with renal progression, identify an optimal risk threshold, and explore antihypertensive drug implications.MethodsWe conducted a retrospective cohort study of 2,143 DKD patients who underwent 24-hour ambulatory BP monitoring (ABPM) between 2018 and 2022, with a median follow-up of 4.8 years. Multiple DBPV parameters including standard deviation (SD), coefficient of variation (CV), average real variability (ARV), and nocturnal dipping were analyzed. Dynamic changes in DBPV were assessed in 1,328 patients with serial ABPM data.ResultsAfter full adjustment, 24-hour DBP ARV was the strongest predictor of renal outcomes. Each 1 mmHg increase was associated with 18% higher odds of rapid estimated glomerular filtration rate (eGFR) decline (OR = 1.18, 95%CI:1.13–1.23), 22% higher ESRD risk (HR = 1.22, 95%CI:1.15–1.29), and 20% higher composite renal event risk (HR = 1.20, 95%CI:1.14–1.26). ROC analysis determined the optimal threshold of 24-hour DBP ARV for ESRD prediction as 10.2 mmHg (sensitivity=76.2%, specificity=61.8%), above which ESRD risk increased 3.1-fold. Patients with increased DBPV over time had a 2.4-fold higher ESRD risk than those with decreased DBPV. Calcium channel blockers (CCBs) were associated with lower DBP ARV than RAAS inhibitors or beta-blockers. Adding 24-hour DBP ARV to traditional risk models significantly improved ESRD prediction (C-statistic: 0.73 to 0.80). The association was stronger in patients with advanced DKD or severely increased albuminuria, and combined high DBP ARV and SBP ARV conferred a 4.5-fold higher ESRD risk.Conclusion24-hour DBP ARV (threshold 10.2 mmHg) is an independent predictor of renal progression in DKD. Rising DBPV amplifies renal risk, and CCBs may better reduce DBPV. Incorporating ABPM-derived DBPV into DKD management improves risk stratification and supports personalized interventions.