Stability of diurnal blood pressure rhythm during 48-hour ambulatory blood pressure monitoring

Evaluation of nocturnal blood pressure (BP) fall is important for prognosis and selection of antihypertensive therapy. We assessed stability of BP diurnal rhythm in 56 hospitalized hypertensive patients by means of 48-hour ambulatory BP monitoring. According to the degree of congruence of BP fall during two nights of monitoring the following groups of patients were distinguished: with similar diurnal BP rhythm in both nights (72% of all patients, including 42% with sufficient and 30% with insufficient nocturnal BP decline), with different diurnal BP rhythms - with sufficient fall of BP in one night and insufficient in another (28% of all patients). BP variability in all patients did not change and could be considered very stable. Thus when insufficient nocturnal BP fall is detected its stability should be confirmed by repeat BP monitoring.