Non-dipping blood pressure in CKD: common, and linked to death and progression

Design

Systematic review and meta-analysis of 63 mainly retrospective studies

Population

54,515 patients with ambulatory BP monitoring (33,825 with CKD)

Primary outcome

Prevalence of non-dipping and associated outcomes in CKD

Effect

Prevalence 53%; dippers vs non-dippers mortality RR 0.60 (95% CI 0.49-0.72)

A systematic review and meta-analysis included 63 studies of patients who had ambulatory blood pressure monitoring: 33,825 with CKD and 20,690 without. Non-dipping was defined as a night-time fall of less than 10%.

About 53% of patients with CKD were non-dippers, and people without CKD were less likely to be (RR 0.69, 95% CI 0.63 to 0.75). Among those with CKD, preserved dipping was associated with lower mortality (RR 0.60), fewer cardiovascular events (RR 0.63) and slower CKD progression (RR 0.64). Almost all studies were retrospective cohorts, and heterogeneity was high.

Clinic readings cannot detect non-dipping, and half of CKD patients have it. This supports using ambulatory monitoring more often in CKD to identify a high-risk group and to confirm control across 24 hours. Whether restoring dipping, for example by moving drugs to the evening, improves outcomes is not shown here; that question has had conflicting trial results.

• Consider ambulatory blood pressure monitoring in patients with CKD, especially when clinic readings and organ damage do not match.
• Treat non-dipping as a marker of higher cardiovascular and renal risk.
• Look for causes of non-dipping such as volume overload and sleep apnoea.
• Do not assume that bedtime dosing will improve outcomes; the evidence is inconsistent.
• Where ambulatory monitoring is unavailable, home readings including an evening measurement may help.

Why it matters

Half of CKD patients have a high-risk blood pressure pattern that clinic readings will never show.

Don't overread it

Observational associations from retrospective cohorts; they do not show that changing night-time pressure improves outcomes.

The statistics, in plain English

A risk ratio of 0.60 for death means dippers had about 40% lower mortality than non-dippers in these studies. Because the studies were observational, non-dipping may be a marker of sicker patients rather than a cause of harm.

Read the rest in the app

You have read your two free briefings this month. The app carries all 27 specialties, every morning, free — and this finding is waiting in it.

Get Daily Doctor — free

Scan to keep reading on your phone. No account needed to start.