Predictive factors for masked hypertension within a population of controlled hypertensives

CONTEXT: Prevalence of masked hypertension (MH) is far from negligible reaching 40% in some studies. The SHEAF study (Self measurement of blood pressure at Home in the Elderly: Assessment and Follow-Up) and others clearly showed that masked hypertension (MH) as detected by home blood pressure measurement (HBPM) is associated with poor cardiovascular prognosis. OBJECTIVE: Systematic HBPM to detect MH is not yet routine. The aim of this work is to better define the clinical profile of masked hypertensives within a population with controlled office blood pressure (BP) and the factors associated with a higher prevalence of MH. MATERIALS AND METHODS: BP was measured at the clinic by the doctor and at home by the patient himself. Risk factors for MH were analysed in a cohort of 1150 treated hypertensive patients over the age of 60 (mean age 70 +/- 6.5, 48.9% men) with controlled office BP. (SBP < 140 mmHg and DBP < 90 mmHg). RESULTS: 463 patients (40%) were masked hypertensives (SBP > or = 135 mmHg or DBP > or = 85 mmHg at home). Three parameters were associated with MH (odds ratio OR): office SBP (OR = 1.110), male gender (OR = 2.214) and age (OR = 1.031). Decision trees showed a 130 mmHg SBP was an efficient threshold to propose HBPM with a higher probability to detect MH. Subsequent variables were male gender and age over 70 in males. CONCLUSION: To detect masked hypertension, it would be logical to first of all select patients whose office SBP is between 130 and 140 mmHg.