Comparison of home and ambulatory blood pressure measurement in the diagnosis of masked hypertension

INTRODUCTION: The best method to diagnose masked hypertension is controversial. The objective of the present study was to compare home blood pressure (HBP) and ambulatory blood pressure (ABP) measurement in the evaluation of masked hypertension. METHODS: Two hundred and sixty-one individuals from the general population underwent office BP (duplicate measurements on four visits), HBP (duplicate measurements on seven days) and 24-h ABP measurement, and risk factor evaluation. Target organ damage was assessed by echocardiography and 24-h urinary albumin measurement. Masked hypertension was defined as normal office BP (<140/90 mmHg) with elevated out-of-office BP (HBP >or=135/85 mmHg, daytime ABP >or=140/85 mmHg or both). RESULTS: HBP and ABP detected 10.6 and 11.4% of masked hypertension, respectively. Only 59% of patients diagnosed as masked hypertensive with ABP measurement also had masked hypertension on HBP measurement. Masked hypertensive patients had higher BMI, waist-to-hip ratio and serum insulin levels than normotensive individuals. They also had greater waist-to-hip ratio than sustained hypertensive individuals. Target organ damage in masked hypertension was between that of normotension and that of sustained hypertension. Office normotensive individuals with elevated HBP tended to have higher rates of cardiovascular risk factors and target organ damage than patients with elevated ABP. CONCLUSION: HBP and ABP detect a similar, but not an identical, group of masked hypertensive individuals. Their agreement in the diagnosis of masked hypertension is only moderate. Our results suggest that HBP measurement can be used to diagnose masked hypertension, but this diagnosis is not analogous with that made with ABP measurement.