Nocturnal Systolic Hypertension and Adverse Prognosis in Patients with CKD

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.