Twenty-four-hour ambulatory blood-pressure variability is associated with total magnetic resonance-imaging burden in cerebral small-vessel disease

Clinical Interventions in Aging Dovepress open access to scientific and medical research Original Research Clinical Interventions in Aging downloaded from https://www.dovepress.com/ by 37.59.46.207 on 21-Dec-2018 For personal use only. Open Access Full Text Article Twenty-four-hour ambulatory blood pressure variability is associated with total magnetic resonance imaging burden of cerebral small-vessel disease This article was published in the following Dove Press journal: Clinical Interventions in Aging Shuna Yang* Junliang Yuan* Wei Qin Lei Yang Huimin Fan Yue Li Wenli Hu Department of Neurology, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China *These authors contributed equally to this work Background: Lacunae, brain atrophy, white matter hyperintensity, enlarged perivascular space and microbleed are magnetic resonance imaging (MRI) markers of cerebral small-vessel disease (cSVD). Studies have reported that higher blood pressure variability (BPV) predicted cardiovascular risk in hypertensive patients; however, the association between BPV and the total MRI burden of cSVD has not been investigated. In this study, we aimed to explore this relationship between BPV and cSVD MRI burden. Methods: We prospectively recruited patients who attended our hospital for annual physical examination. Twenty-four-hour ambulatory BP monitoring was performed using an automated system. BPV was quantified by SD, weighted SD, and coefficient of variation. One point was awarded for the presence of each marker, producing a score between 0 and 5. Spearman correlation and ordinal logistic regression analyses were used to test the relationship between BPV and total cSVD MRI burden. Results: A total of 251 subjects with an average age of 68 years were enrolled in this study, and 52.6% were male; 163 (64.94%) had one or more markers of cSVD. Correlation analysis indicated that higher systolic BP (SBP) levels and BPV metrics of SBP were positively related to higher cSVD burden. Ordinal logistic regression analyses demonstrated that higher SBP levels and SBP variability were independent risk factors for cSVD. There were no significant differences in 24-hour, day and night diastolic BP levels or BPV metrics of diastolic BP among the five subgroups. Conclusion: Twenty-four-hour, day and night SBP levels and SBP variability were positively related to cSVD burden. Higher SBP levels and SBP variability were independent risk factors for cSVD. Keywords: cerebral small-vessel diseases, blood pressure variability, ambulatory blood pressure monitoring, magnetic resonance-imaging burden Introduction Correspondence: Wenli Hu Department of Neurology, Beijing Chaoyang Hospital, Capital Medical University, 8 Gongti South Road, Chaoyang, Beijing 100020, China Tel +86 10 8523 1376 Email 1419 submit your manuscript | www.dovepress.com Clinical Interventions in Aging 2018:13 1419–1427 Dovepress © 2018 Yang et al. This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at https://www.dovepress.com/terms.php and incorporate the Creative Commons Attribution – Non Commercial (unported, v3.0) License (http://creativecommons.org/licenses/by-nc/3.0/). By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms (https://www.dovepress.com/terms.php). http://dx.doi.org/10.2147/CIA.S171261 Powered by TCPDF (www.tcpdf.org) Cerebral small-vessel disease (cSVD) is caused by a group of pathological processes involving the perforating cerebral arterioles, capillaries, and venules of the brain.1 Lacunae (small subcortical cerebral spinal fluid-containing cavities, typically .3 mm and ,15 mm in diameter), brain atrophy (lower brain volume not related to a specific macroscopic focal injury, such as trauma), white-matter hyperintensity (WMH; hyperintense areas on T2-weighted sequences and fluid-attenuated inversion recovery [FLAIR], isointense or hypointense areas on T1-weighted sequences with respect to normal brain), enlarged perivascular space (EPVS; perivascular compartments following the courses of small penetrating cerebral vessels, similar signal to cerebral spinal fluid), and Dovepress Clinical Interventions in Aging downloaded from https://www.dovepress.com/ by 37.59.46.207 on 21-Dec-2018 For personal use only. Yang et al microbleed (small punctate areas of hypointense on T2*- or susceptibility-weighted imaging [SWI] that are up to 10 mm in diameter) are considered magnetic resonance imaging (MRI) markers of cSVD.2,3 cSVD is a common vascular factor in dementia, a major contributor to mixed dementia, and the cause of about a fifth of all strokes worldwide.2 However, the pathogenesis of cSVD is not completely understood. Hypertension is a well-known major risk factor for cSVD.4,5 Twenty-four-hour ambulatory blood pressure monitoring (ABPM) has been proven to be a more useful and scientific method for predicting BP-related brain damage than single office BP measurement,6,7 and 24-hour ABP variability (ABPV) can be documented by 24-hour ABPM. Previous studies have shown that increased 24-hour ABPV is associated with increased target-organ damage, including cardiovascular and cerebrovascular events.8–10 Recent studies have demonstrated that higher 24-hour ABPV is associated with WMH, lacunar infarction, cSVD progression, and cognitive decline.11,12 In addition, some studies have found that higher 24-hour ABP levels are related to WMH, EPVS, and new cerebral microbleeds.13–15 However, these studies mostly focused separately on different MRI markers of cSVD. A “total cSVD score” was introduced to combine all single MRI markers of cSVD into one measure, which aimed to evaluate the total brain damage from cSVD.16,17 Age, hypertension, higher ABP levels, and other risk factors for cSVD have been found to be associated with total cSVD score.16,17 The previous “total cSVD score” did not take brain atrophy into consideration. Imaging studies have reported that the presence and severity of cSVD are associated with brain atrophy.18,19 Additionally, brain atrophy has been considered an important imaging measure in several studies that aimed to assess vascular damage to the brain, and it is thought to mediate, at least partially, the effects of vascular lesions on cognition.2,20,21 A scientific statement for cSVD from the American Heart Association/American Stroke Association also included brain atrophy as an MRI marker of cSVD.3 Therefore, in our opinion, brain atrophy should be included in the total cSVD score. To the best of our knowledge, no study has explored the relationship between 24-hour ABPV and total MRI burden of cSVD, including lacunae, brain atrophy, WMH, EPVS, and microbleeds. Therefore, in this stu (...truncated)