Prognostic Effect of Isolated Nocturnal Hypertension in Chinese Patients With Nondialysis Chronic Kidney Disease

Abstract

Background: Isolated nocturnal hypertension (INH) has been studied among the general population and hypertensive patients. However, little insight is available on the prognostic effect of INH in patients with chronic kidney disease (CKD). This study investigated the prognostic effect of INH in a cohort of Chinese patients with nondialysis CKD.

Methods and results: A total of 588 Chinese CKD patients who were admitted to the Third Affiliated Hospital of Sun Yat-Sen University were enrolled in this study. We monitored blood pressure (BP) throughout the day and followed health outcomes in the 588 CKD patients admitted to our hospital division. We recorded time to total mortality, cardiovascular mortality, renal events, and cardiovascular events. A total of 370 (62.92%) individuals had nocturnal hypertension, which included 136 (23.13%) patients with INH. Multivariable Cox regression analyses showed that nocturnal BP was a significant risk factor for renal events and cardiovascular events in CKD patients, even when adjusted for clinic BP, 24-hour BP, or daytime BP. Patients with nocturnal hypertension showed a worse prognosis compared with patients with nocturnal normotension (P<0.05), and nocturnal hypertension (versus nocturnal normotension) was associated with an increased risk for renal events (hazard ratio [HR], 3.81; 95% CI, 1.74-8.36) and cardiovascular events (HR, 8.34; 95% CI, 1.98-35.07). In addition, patients with INH had a worse prognosis than patients with normotension (P<0.017), whereas INH (versus normotension) was associated with a higher risk of renal events (HR, 2.78; 95% CI, 1.16-6.65) and cardiovascular events (HR, 6.82; 95% CI, 1.52-30.63).

Conclusions: INH was associated with a poor prognosis in Chinese nondialysis CKD patients.

Keywords: ambulatory blood pressure monitoring; chronic kidney disease; hypertension; isolated nocturnal hypertension; kidney; kidney (diabetes); prognosis.

Figure 1

Patient selection and assignment to different ambulatory blood pressure status. ABPM indicates ambulatory blood pressure monitoring; CKD, chronic kidney disease; eGFR, estimated glomerular filtration rate.

Figure 2

Kaplan–Meier survival curves as a function of patients with or without nocturnal hypertension. A, Cumulative survival curves for total mortality in patients with or without nocturnal hypertension. B, Cumulative survival curves for cardiovascular mortality in patients with or without nocturnal hypertension. C, Cumulative survival curves for renal events in patients with or without nocturnal hypertension. D, Cumulative survival curves for cardiovascular events in patients with or without nocturnal hypertension. P<0.001 indicated a comparison between the nocturnal normotension and nocturnal hypertension groups.

Figure 3

Kaplan–Meier survival curves as a function of patients with normotension (NT), isolated nocturnal hypertension (INH), or day‐night sustained hypertension (DNH). A, Cumulative survival curves for total mortality in patients with INH or NT or DNH. B, Cumulative survival curves for cardiovascular mortality in patients with INH or NT or DNH. C, Cumulative survival curves for renal events in patients with INH or NT or DNH. D, Cumulative survival curves for cardiovascular events in patients with INH or NT or DNH. P<0.001 indicated a comparison between these 3 groups.