Normotensive non-dipping blood pressure profile does not predict the risk of chronic kidney disease progression

The lack of a decrease in nocturnal blood pressure is a risk factor for the progression of chronic kidney disease (CKD); however, it currently remains unknown whether it is a risk factor in normotensive CKD patients. We conducted a retrospective cohort study and enrolled 676 CKD patients who underwent ambulatory blood pressure monitoring (ABPM). According to their nocturnal blood pressure dipping pattern (>10%: dipper or <10%: non-dipper) and average 24-h systolic blood pressure (>130/80 mmHg: hypertension or <130/80 mmHg: normotension), patients were divided into four groups. The estimated glomerular filtration rate (eGFR) decline over 2 years and relevant clinical parameters were analyzed among groups. Among all participants, 82.7% were non-dippers and half of them were normotensive. The eGFR decline was the most rapid in hypertensive non-dipper patients (4.73 ± 0.45 ml/min/1.73 m²/2 years), and was not significantly different between normotensive non-dipper (1.31 ± 0.49 ml/min/1.73 m²/2 years) and dipper patients (1.69 ± 0.80 ml/min/1.73 m²/2 years). A multivariate regression analysis revealed that the amount of urinary protein (95% confidence interval (CI): 1.51-2.63), 24-h systolic blood pressure (95% CI 1.13-1.45), and eGFR (95% CI 1.02-1.44) were associated with a rapid eGFR decline. We conclude that, according to the ABPM-based analysis, a non-dipping blood pressure pattern in normotensive CKD patients does not predict the risk of a rapid decline in eGFR. This suggests that the control of blood pressure, rather than its circadian rhythm, is essential for the preservation of eGFR.