Characteristics and Predictors of Masked Hypertension in Elderly Patients with Well-controlled Hypertension

ABSTRACT

BACKGROUND: Clinic-based blood pressure measurements may lead to untoward results in the management of hypertension. Masked hypertension (MH) has been shown to be related to a poor prognosis due to its hidden nature. The purpose of this study is to present the clinical predictors of MH in elderly patients over 65 years with well-controlled clinic blood pressure (CBP) and to evaluate the gap, the 'mask effect' (negative white-coat effect), between CBP and home blood pressure (HBP). METHODS: The BPs of 1,019 treated hypertensive patients were measured by a doctor at an out-patient clinic and by patients themselves at home. Clinical parameters for MH were analyzed in 511 patients with well-controlled CBP (45.6% men, mean age 57.1+/-9.0 years). RESULTS: Among the patients over 65 years (n=113, 46.8% men, mean age 68.4+/-7.3 years) and with well-controlled CBP, the prevalence of MH was 26.5% (30 patients). In multivariate-adjusted analysis, the risk of MH increased with physical inactivity (odds ratio [OR], 2.942; 95% confidence interval [CI], 1.039-8.329; p=0.042), use of beta-blocker (OR, 4.242; 95% CI, 1.528-11.785; p=0.06) and systolic clinic BP (OR, 1.083; 95% CI, 0.017-1.154; p=0.013). Furthermore, HBP correlated well with CBP (r=0.329; p<0.001) and further with degree of ME (r=0.723; p<0.001). CONCLUSION: In looking for MH, it would be useful to carefully assess patients taking beta-blockers, having higher CBP, and who are physically inactive by using self-monitoring home or ambulatory BP monitoring.