THE ASSOCIATION OF MASKED HYPERTENSION AND TARGET ORGAN DAMAGES IN TWO KOREAN POPULATIONS IN RURAL AREAS

Abstract

Objective: Masked hypertension (MH) in hypertension (HT) management is marked with poor prognosis regardless of the drug therapy. But the physiology or pathogenesis behind is not well understood. Clinical study results have been focused on the neglected pressure overload which could result in more subclinical organ damage. But epidemiologic study on MH showed highly variable results regarding the prevalence and the associated factor with MH.

Design and Method: For the subject participated in ambulatory blood pressure monitoring (ABPM) examination during epidemiologic survey performed in Yangpyeong and Yeojoo counties in year 2009 and 2011, respectively. Subjects in Yangpyeong was relatively older (56.3 ± 10.4 (n = 133) vs 46.3 ± 8.5 (n = 180), p = <0.0001). MH was defined as normal clinic BP and elevated daytime ABPM 3 135/85 mmHg. Asymptomatic target organ damage such as echocardiographic left ventricular mass index (LVMI), brachial ankle pulse wave velocity (baPWV), ankle brachial index (ABI), and estimated GFR (eGFR) related to MH were investigated.

Results: Age was 50.5 ± 10.5 and the female was 54%. The overall prevalence of MH was 29.7% (n = 81/273) whereas whitecoat HT and sustained HT were 6.2% (n = 17/273) and 14.3% (n = 39/273), respectively. Compared to normotension, MH showed significantly higher baPWV (1442.8 vs 1332.7 cm/sec, p = 0.0002) but there were no differences in LVMI (73.3 ± 21.4 vs 76.4 ± 21.5 gm/m², p = 0.3179), ABI, or eGFR. Compared to normotensive or MH, sustained HT group showed significantly higher LVMI (73.3 ± 21.4 vs 91.9 ± 19.6 gm/m², p < 0.0001) and baPWV (1332.7 ± 215.5 vs 1704.1 ± 289.3 cm/s, p < 0.0001). Compared to MH, sustained HT showed significantly higher baPWV (p < 0.0001) and LVMI (p = 0.0002).

Conclusions: In our population study including relatively young subjects, it was shown that vascular stiffness was more sensitive marker to demonstrate the difference in the organ damage between normotensive and masked hypertension.