Lower ambulatory nocturnal SBP is associated with less cardiovascular and renal damage in normotensive hospitalized patients with chronic kidney disease

Objective: The impact of nocturnal blood pressure (BP) on target organ damage (TOD) in chronic kidney disease (CKD) patients with normotension has not been established. In this study, we determined whether nocturnal BP is correlated with cardiovascular and renal damage independent of the 24-h BP in CKD patients with normotension or hypertension.

Methods: A total of 1166 hospitalized patients with CKD not requiring dialysis were enrolled in this cross-sectional study, 421 and 745 of whom had normotension and hypertension, respectively. TOD was assessed by the left ventricular mass index (LVMI), estimated glomerular filtration rate (eGFR) and presence of proteinuria. Univariate and multivariable regression analyses were used to evaluate the relationships between nocturnal BP and TOD.

Results: In the multivariable-adjusted models, including the 24-h BP, nocturnal SBP was independently associated with the LVMI, eGFR and proteinuria in patients with normotension (P < 0.05), while the nocturnal DBP was not correlated with proteinuria. The nocturnal SBP was associated with LVMI and proteinuria, but not the eGFR in patients with hypertension. We did not demonstrate an association between nocturnal DBP and TOD in these patients. When nocturnal SBP in patients with normotension was further divided into tertiles [tertile 1 (<104 mmHg), tertile 2 (104-114 mmHg) and tertile 3 (≥114 mmHg)], multivariate analysis showed that tertile 3 was independently associated with TOD.

Conclusion: Nocturnal SBP was shown to be an independent risk factor for TOD in patients with normotension. Targeting a nocturnal ambulatory SBP to less than 114 mmHg or even less than 104 mmHg may help prevent TOD in patients with CKD.