Discussion on using ambulatory blood pressure monitoring in the diagnostic criteria of white coat and masked hypertension / 上海交通大学学报（医学版）

ABSTRACT

Objective • To investigate different methods on the diagnosis of white coat and masked phenomena in ambulatory blood pressure monitoring (ABPM). Methods • Information of clinical characteristics and laboratory data were collected, and measurements of office blood pressure (OBP) and ambulatory blood pressure (ABP) in 274 subjects were performed, including 46 persons with high normal OBP (SBP/DBP 130-139/85-89 mmHg) (1 mmHg=0.133 kPa), 187 untreated patients with grade 1 and grade 2 hypertension (SBP/DBP 140-179/90-109 mmHg), and 41 treated hypertensive patients. Differences of 95th and 5th percentile between OBP and daytime ABP, were respectively taken as the cutoff for the definition of white coat phenomenon and masked phenomenon. Results • If white coat and masked phenomenon were diagnosed according to the current hypertension guidelines, the prevalence of white coat phenomenon did not differ between untreated and treated hypertensive patients (11.2% vs 7.3%, P=0.460). In the untreated group, the prevalence of white coat phenomenon was higher in grade 2 than in grade 1 hypertension (20.0% vs 8.5%, P=0.033), whereas the prevalence of white coat hypertension did not differ (2.2% vs 7.0%, P=0.230). The prevalence of masked hypertension was 73.9% in high normal blood pressure group. The prevalence of masked uncontrolled hypertension was 4.9%. If the difference of 95th percentile (≥20.50/20.50 mmHg) and 5th percentile (≤-18.67/-6.00 mmHg) between OBP and daytime ABP were, respectively, used as the cutoff for the definition of white coat and masked phenomenon, the prevalence of white coat phenomenon did not differ between treated and untreated groups (12.2% vs 9.1%，P=0.543). In the untreated group, the prevalence of white coat phenomenon was higher in grade 2 than in grade 1 hypertension (24.4% vs 4.2%, P=0.000). The prevalence of masked phenomenon did not differ between persons with high normal OBP (15.2%) and untreated (5.9%) as well as treated hypertensive patients (12.2%) (P>0.05). Conclusion • The percentile methods may be useful for the diagnosis of white coat and masked phenomena.