PREVALENCE OF WHITE-COAT HYPERTENSION AND MASKED HYPERTENSION IN KOREAN AMBULATORY BLOOD PRESSURE REGISTRY FOR PRIMARY CARE CLINIC SETTING, PILOT STUDY DATA

Abstract

Objective: Ambulatory blood pressure (ABP) monitoring was recommended as the preferred diagnostic tool to clinic blood pressure (CBP) measurement in diagnosing hypertension. But the implementation issue for primary care physician, the major service provider in hypertension, has been challenging and clinical implication of ABP monitoring (ABPM) in primary care setting is largely unknown in Korea.

Design and Method: For 32 primary care clinic distributed in South Korea, 259 subjects were enrolled for the pilot study in preparing large scale ABPM registry in primary car setting in 2015. White-coat hypertension (WCH) was defined as CBP3 140/90 mmHg and daytime ABP < 135/85 mmHg and masked hypertension (MH) was defined as CBP < 140/90 mmHg and daytime ABP3 135/85 mmHg.

Results: Age was 54.5 ± 13.4 (n = 259) and female was 46.3%. CBP was 133.1 ± 20.5 mmHg and daytime ABP was 129.4 ± 15.9 mmHg. Nocturnal systolic blood pressure (BP) was 120.6 ± 16.6 mmHg and non-dipper was 64.9%. WCH and MH were 15.8% and 10.0%, respectively. For 98 subjects on antihypertensive medication, calcium antagonist was the most frequently prescribed (82.5%). WCH and MH for treated patients were 16.3% and 9.2%, respectively. Among the factor tested for MH, only abdominal circumference was with borderline significance (OR: 1.22, p = 0.07). For WCH, no factor was suggested to be related.

Conclusions: In the pilot study, relatively lower prevalence of masked hypertension could suggest the difference in the clinic environment or clinical background of the patents. But abdominal obesity may be a significant remaining factor for masked hypertension in primary care setting.