Predictors of masked hypertension among treated hypertensive patients: An interesting association with orthostatic hypertension

Background Masked hypertension (MH) entails an increased cardiovascular risk. Therefore, it is important to identify those individuals who would benefit the most from out-of-office blood pressure (BP) measurement. We sought to determine the prevalence and identify predictors of MH among adult hypertensive patients under treatment. Methods Treated hypertensive patients aged ≥ 18 years underwent office (duplicate sitting and standing BP in 1 visit) and home BP measurements (duplicate measurements for 4 days in the morning, afternoon, and evening; at least 16 measurements) and completed a questionnaire regarding risk factors and history of cardiovascular disease. MH was defined as normal office BP (<140/90mm Hg) with elevated home BP (≥135/85mm Hg, average of all readings discarding first day measurements). Patients with a systolic BP rise upon standing ≥5mm Hg were considered to have orthostatic hypertension (OHT). Variables indentified as relevant predictors of MH were entered into a multivariable logistic regression analysis model. Results Three hundred and four patients were included (mean age = 66.7 ±13.8; 67.4% women). The prevalence of MH in the whole population was 12.4% and was 20.9% among patients with office-controlled hypertension. Factors independently associated with MH were age (odds ratio (OR) = 1.08, 95% confidence interval (CI) = 1.03-1.14), high-normal office systolic BP (OR = 5.61, 95% CI = 1.39-22.57), history of peripheral artery disease (PAD) (OR = 8.83, 95% CI = 1.5-51.84), moderate alcohol consumption (OR = 0.08, 95% CI = 0.01-0.73), and OHT (OR = 3.65, 95% CI = 1.27 to 10.51). Conclusions Easily measurable parameters such as age, office systolic BP, history of PAD, and OHT may help to detect a population at risk of MH that would benefit from home BP monitoring.