Factors Associated with Baroreflex Sensitivity: Association with Morning Blood Pressure

Eguchi, Kazuo; Tomizawa, Hidenori; Ishikawa, Joji; Hoshide, Satoshi; Pickering, Thomas G.; Shimada, Kazuyuki

doi:10.1291/hypres.30.723

Cited by 21 publications

(13 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Although the maximum home SBP differs from BP variability in that it refers specifically to transient changes in BP, these 2 variables often have similar associations with other clinical indices, such as arterial stiffness and baroreceptor dysfunction. 1,24,25 In the present study, age and PWV, both of which may be involved in the impairment of the arterial baroreflex, 26,27 were independent determinants of the size of the maximum home SBP. Thus, a baroreceptor dysfunction could be potentially involved in the mechanisms of larger-value maximum home SBP.…”

Section: Discussionsupporting

confidence: 49%

Maximum Value of Home Blood Pressure

et al. 2011

Self Cite

View full text Add to dashboard Cite

Abstract-The maximum office systolic blood pressure (SBP) has been shown to be a strong predictor of cardiovascular events, independently of the mean SBP level. However, the clinical implications of maximum home SBP have never been reported. We investigated the association between the maximum home SBP and target organ damage (TOD). We assessed the left ventricular mass index (LVMI) and carotid intima-media thickness (IMT) using ultrasonography and the urinary albumin/creatinine ratio (UACR) as measures of TOD in 356 never-treated hypertensive subjects. Home BP was taken in triplicate in the morning and evening, respectively, for 14 consecutive days with a memory-equipped device. The maximum home SBP was defined as the maximum mean triplicate BP reading in the 14-day period for each individual and was significantly correlated with LVMI (rϭ0.51, PϽ0.001), carotid IMT (rϭ0.40, PϽ0.001), and UACR (rϭ0.29, PϽ0.001). The correlation coefficients with LVMI and carotid IMT were significantly larger for the maximum home SBP than the mean home SBP. In multivariate regression analyses, the maximum home SBP was independently associated with LVMI and carotid IMT, regardless of the mean home BP level. In the prediction of left ventricular hypertrophy and carotid atherosclerosis, the goodness-of-fit of the model was significantly improved when the maximum home SBP was added to the sum of the mean office and home BPs (Pϭ0.002 and PϽ0.001, respectively). These findings indicate that assessment of the maximum home SBP, in addition to the mean home SBP, might increase the predictive value of hypertensive TOD in the heart and artery. Key Words: maximum home systolic blood pressure Ⅲ mean home systolic blood pressure Ⅲ left ventricular mass index Ⅲ carotid intima-media thickness Ⅲ urinary albumin/creatinine ratio Ⅲ aging Ⅲ arterial stiffness I t has been believed that transient increases in blood pressure (BP) might be construed as noise and merely an obstacle to reliable estimation of usual BP (conceived as the true underlying average BP over a period of time). In this case, such increases would result in substantial underestimation of the strength of the real association between usual BP and cardiovascular risk, a so-called "regression dilution bias." 1 Rothwell et al 2 recently showed that the maximum systolic BP (SBP) reached in an office setting was a strong predictor of cardiovascular events, independently of the mean SBP over 12 to 36 months. Ko et al 3 also showed that the maximum SBP during the first 72 hours of acute ischemic stroke was strongly associated with the development of brain hemorrhagic transformation, independently of the mean SBP level. Thus, subjects with episodic high BP might be at a high cardiovascular risk.One drawback of the use of the maximum SBP in routine clinical management of hypertension is that obtaining it requires several office visits over a period of time. One possible way to solve this is to observe the maximum SBP derived from self-measurement at home, because this selfmeasurement makes it p...

show abstract

Section: Discussionsupporting

confidence: 49%

Maximum Value of Home Blood Pressure

et al. 2011

Self Cite

View full text Add to dashboard Cite

show abstract

“…We felt it important to clearly delineate these mechanisms in otherwise healthy individuals to document the "normal" physiological response in the absence of any cofounding pathology and/or medications. Although the study of young healthy individuals is limited as far as generalizing the results to clinical populations, diurnal variation in baroreflex sensitivity is robust in hypertensive patients, 12,13 and our findings, therefore, bring to question whether better management of cardiovascular events may be achieved through interventions targeted specifically at the neural and/or mechanical components. The potential for the use of targeted therapy has been suggested in relation to sympathetic baroreflex function.…”

Section: Clinical Perspectivesmentioning

confidence: 80%

“…35 Studies using spontaneous baroreflex indices have consistently shown that the highest sensitivities occur during the night, with reduced sensitivities in the morning after waking. 10,12,13,33 However, the variations during the daytime have not been consistent between studies. For example, Tochikubo et al 12 found the circadian variation to be bimodal with a secondary peak in baroreflex sensitivity at 7:00 PM and trough at 11:00 PM.…”

Section: Comparison With Previous Studiesmentioning

confidence: 88%

Diurnal Variation in the Mechanical and Neural Components of the Baroreflex

et al. 2011

View full text Add to dashboard Cite

Abstract-Diminished baroreflex sensitivity in the morning negatively influences morning coronary blood flow and blood pressure control in hypertensive patients. Our aim was to determine the contribution of the mechanical and neural components of the cardiac baroreflex to diurnal variation in blood pressure control. In 12 healthy participants, we used the modified Oxford method to quantify baroreflex sensitivity for rising (G up ) and falling (G down ) pressures in the morning (7:00 AM) and afternoon (4:00 PM). Beat-to-beat blood pressure, R-R intervals, and carotid artery diameter measurements were recorded. Integrated sensitivity was determined by plotting R-R intervals against systolic blood pressure. The mechanical component was carotid artery diameter plotted against systolic blood pressure, and the neural component was R-R intervals plotted against carotid artery diameter. Linear mixed models were used to compare the integrated, mechanical, and neural sensitivities between morning and afternoon. We found significant diurnal variation in integrated sensitivity, with an attenuated response in the morning (G up ϭ13.0Ϯ0.6; G down ϭ6.3Ϯ0.4 ms/mm Hg) when compared with the afternoon (G up ϭ15.1Ϯ0.6; G down ϭ12.6Ϯ0.4 ms/mm Hg). For rising pressures, the diminished integrated sensitivity in the morning was caused by a reduction in mechanical sensitivity, whereas for falling pressures it was caused by a reduction in neural sensitivity. Our findings explicate the mechanisms underlying diurnal variation in baroreflex function. Pharmacological and lifestyle interventions targeted specifically at the diminished component of the cardiac baroreflex in the morning may lead to better management of hypertension. (Hypertension. 2011;58:51-56.)Key Words: circadian rhythms Ⅲ baroreflex Ⅲ blood pressure Ⅲ heart rate Ⅲ carotid artery B lood pressure (BP) exhibits a circadian rhythm, with the lowest pressures occurring during nocturnal sleep and a rapid "morning surge" after waking. 1 BP is most reactive to a given level of physical activity in the morning, 2 and risk of orthostatic intolerance is also greater at this time compared with the afternoon. 3 In a number of prospective studies (reviewed by Kario 4 ), the morning surge in BP has been found to be an independent risk factor for cardiovascular and cerebrovascular events, which also peak between 6:00 AM and 12:00 PM. 5,6 There is a wealth of evidence that BP control varies significantly over a 24-hour period, with studies in the frequency domain indicating the presence of a circadian rhythm in sympathovagal balance. 7,8 However, investigations directed at unraveling the autonomic mechanisms governing these time-of-day differences are lacking.The arterial baroreflex control of vagal neural outflow is quantified by the responses in R-R interval to changes in systolic BP. 9 Previous studies have identified diurnal variation in baroreflex sensitivity in both normotensive and hypertensive people, with reduced sensitivities after waking compared with during sleep. 10 -13 Moreover,...

show abstract

“…Morning SBP has been shown to inversely correlate with baroreflex sensitivity (37) and to be a strong risk marker for stroke in elderly subjects (38). The morning SBP surge has also been reported as a predictor of cerebrovascular events (12,13).…”

Section: Discussionmentioning

confidence: 99%