Subclinical arterial damage in untreated masked hypertensive subjects detected by home blood pressure measurement

Background: Masked hypertension (MHT: normal office blood pressure [BP] + elevated BP out of the office) is a significant predictor of target organ damage and cardiovascular disease. The purpose of this study was to investigate the subclinical arterial damage in unmedicated subjects with MHT detected by home BP measurement. Methods: We recruited 282 subjects not taking antihypertensive medication, who had at least one of the following five cardiovascular risk factors: high BP, hyperlipidemia, diabetes mellitus, current smoking, and chronic kidney disease. Furthermore, we classified them into four groups (normotension [NT], white-coat hypertension [WCHT], MHT, and sustained hypertension [SHT]) by office BP (140/90 mm Hg) and home BP (135/85 mm Hg) measurements. Arterial damage was evaluated by measuring carotid intima-media thickness (IMT) and brachial-ankle pulse wave velocity (baPWV). Results: Subjects with MHT had a higher prevalence of habitual alcohol drinkers than the other groups, and higher pulse rates at home than those with NT and WCHT. After adjustment for covariates, carotid IMT was the highest in MHT among the four groups (mean: 1.01 v 0.83 mm for NT, 0.86 mm for WCHT, and 0.91 mm for SHT, all P<.01). The baPWV was also significantly higher in MHT than NT and WCHT (mean: 1940 v 1663 and 1733 cm/sec, all P<.01), whereas the difference between MHT and SHT (2023 cm/sec) was not significant. Conclusions: This study shows that masked hypertensives detected by home BP are at higher risk for increased arterial damage than normotensives or white-coat hypertensives, and potentially than sustained hypertensives.