Nocturnal Systolic Hypertension and Adverse Prognosis in Patients with CKD

Abstract

Background and objectives: Nocturnal hypertension is associated with adverse outcomes in patients with CKD. However, the individual association of entities of nocturnal hypertension according to achievement of systolic and/or diastolic BP goals with kidney failure and cardiovascular outcomes of CKD is not clear.

Design, setting, participants, & measurements: Our study analyzed data from participants in the Chinese Cohort Study of Chronic Kidney Disease. Nocturnal hypertension was categorized into three entities: isolated nocturnal diastolic hypertension with diastolic BP ≥70 mm Hg and systolic BP <120 mm Hg, isolated nocturnal systolic hypertension with systolic BP ≥120 mm Hg and diastolic BP <70 mm Hg, and nocturnal systolic-diastolic hypertension with both systolic BP ≥120 mm Hg and diastolic BP ≥70 mm Hg. Associations of nocturnal hypertension entities with kidney failure and cardiovascular outcomes were evaluated by Cox regression.

Results: In total, 2024 patients with CKD stages 1-4 were included in our analysis (mean age, 49±14 years; 57% men; eGFR=51±29 ml/min per 1.73 m²; proteinuria: 0.9 [0.4-2.1] g/d). Among them, 1484 (73%) patients had nocturnal hypertension, with the proportions of 26%, 8%, and 66% for isolated nocturnal diastolic hypertension, isolated nocturnal systolic hypertension, and nocturnal systolic-diastolic hypertension, respectively. Three hundred twenty kidney events and 148 cardiovascular events were recorded during median follow-up intervals of 4.8 and 5.0 years for kidney and cardiovascular events, respectively. After adjustment, isolated nocturnal systolic hypertension was associated with a higher risk for cardiovascular events (hazard ratio, 3.17; 95% confidence interval, 1.61 to 6.23). Nocturnal systolic-diastolic hypertension showed a higher risk for both kidney failure (hazard ratio, 1.71; 95% confidence interval, 1.17 to 2.49) and cardiovascular outcomes (hazard ratio, 2.19; 95% confidence interval, 1.24 to 3.86). No association was observed between isolated nocturnal diastolic hypertension with either kidney failure or cardiovascular events.

Conclusions: Nocturnal systolic hypertension, either alone or in combination with diastolic hypertension, is associated with higher risks for adverse outcomes in patients with CKD.

Keywords: ambulatory blood pressure monitoring; cardiovascular events; chronic kidney disease; end-stage renal disease; hypertension; nocturnal systolic hypertension.