Impaired cerebral vasoreactivity in white coat hypertensive adolescents

Background and purpose: Although its incidence is not high, adolescent hypertensionmay predict hypertension and increased cardiovascular risk in adulthood. Therefore,the aim of the present study was to assess whether cerebrovascular reactivity is alteredin adolescent white coat and sustained hypertensive patients compared to healthyteenagers.Methods: Fifty-nine normotensive, 47 white coat hypertensive (WCH), and 73 sus-tained hypertensive (SH) adolescents were studied. WCH and SH were differentiatedby ambulatory blood pressure monitoring. Cerebrovascular reactivity was assessed bytranscranial Doppler breath-holding test and was expressed in percent (%) change tothe resting cerebral blood flow velocity value.Results: The percent increase in middle cerebral artery mean blood flow velocity after30 s of breath holding was lower in both WCH (5.3 ± 3.1%) and SH (9.5 ± 2.6%)groups indicating lower vasodilatory reactivity compared to healthy adolescents(12.1 ± 2.2%). Additionally, serum nitric oxide (NOx) concentrations were lower inboth WCH (30.6 ± 11 lM) and SH (30.7 ± 22.4 lM) groups compared to controls(38.8 ± 7.6 lM).Conclusions: Both white coat and sustained hypertension result in decreased vaso-dilatory reaction to CO