Reproducibility of blood pressure variability, white‐coat effect and dipping pattern in untreated, uncomplicated and newly diagnosed essential hypertension

Abstract

Objective: To investigate the reproducibility of blood pressure (BP) variability, white‐coat effect (WCE) and nocturnal dipping pattern in untreated patients with uncomplicated essential hypertension using 24‐hour ambulatory BP monitoring (ABPM). Methods: Seventy‐five newly diagnosed, untreated essential hypertensive subjects (54 men, 21 women 47.6 ± 9.3 years) were recruited for the study based on conventional measured BP from a total of 180 patients referred for ABPM. Of these, 65 patients underwent repeated ABPM after 4 weeks observation without treatment. Reproducibility of BP, nocturnal dipping pattern, WCE and BP variability were assessed using different methods. Results: The average 24‐hour BP (140.8 ± 11.9/91.8 ± 6.4 vs. 140.5 ± 14.5/90.7 ± 7.6 mmHg, ns) or PP (49.6 ± 10.8 vs. 49.8 ± 9.8 mmHg, ns) did not change, nor did daytime BP or PP. The WCE diminished significantly during the observation period (reduction in SBP WCE Δ8.2 ± 12.5 mmHg, p < 0.0001, in DBP WCE, Δ3.3 ± 9.2 mmHg, p = 0.008 and in PP WCE Δ4.8 ± 11.2 mmHg, p = 0.002). Variability in SBP, DBP and PP decreased consistently and significantly during the observation period. The nocturnal dipping pattern was unchanged in 82% of the patients. In 12% non‐dipping pattern was converted to dipping pattern after repeated measurement. Conclusion: Average ABPs are highly reproducible in patients with uncomplicated essential hypertension of limited duration. Similarly, nocturnal dipping pattern reproduced satisfactorily. These measures have important clinical applicability. The white‐coat effect as well as variability are greatly attenuated during repeated measurements, and these measures may thus be of less utility in clinical practice.