Non-symmetrical double-logistic analysis of 24-h blood pressure recordings in normotensive and hypertensive rats

Head, Geoffrey A.; Лукошкова, Е. В.; Mayorov, Dmitry N.; Buuse, Maarten van den

doi:10.1097/00004872-200411000-00008

Cited by 32 publications

(40 citation statements)

References 22 publications

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“…times greater). Interestingly, this is closely similar to what we observed in spontaneously hypertensive rats, in whom the arousal rate of increase in HR was 2.4 times the rate of decline (4). By contrast, normotensive rats showed a symmetrical HR pattern.…”

Section: Discussionsupporting

confidence: 90%

Nonsymmetrical double logistic analysis of ambulatory blood pressure recordings

Head

Reid

Лукошкова³

2005

Journal of Applied Physiology

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Head, Geoffrey A., Christopher M. Reid, and Elena V. Lukoshkova. Nonsymmetrical double logistic analysis of ambulatory blood pressure recordings. J Appl Physiol 98: [1511][1512][1513][1514][1515][1516][1517][1518] 2005. First published November 5, 2004; doi:10.1152/japplphysiol.00647.2004.-We developed an asymmetric double logistic curve-fitting procedure for circadian analysis that can determine the rate of change in variables during the day-to-night separately from the night-to-day transition for use in animal studies. We now have applied this procedure to 24-h systolic (SAP) and diastolic arterial pressure (DAP) and heart rate ambulatory recordings from 302 patients. In 292 cases, all parameters showed a pattern of higher day and lower night values. In men there was a similar rate of transition between day and night or from night to day for both SAP and DAP that lasted 3-4 h, indicating a symmetrical diurnal pattern. By contrast, women showed a faster rate of decrease in mean arterial pressure in the evening compared with men (P Ͻ 0.05) and therefore showed an asymmetric diurnal SAP pattern. For both men and women, there was a markedly greater rate of morning increase in heart rate compared with the rate of evening decrease (2.2-and 1.9-fold, respectively, P Ͻ 0.001). The logistic method provided a better fit than the square-wave or the cosinor method (P Ͻ 0.001) and more appropriately detected nondippers. We conclude that analysis of ambulatory recordings by a new logistic curve-fitting method reveals more rapid reductions in evening SAP in women than men but both have two-to threefold more rapid morning rates of tachycardia. The ability of the double logistic method to determine the diurnal blood pressure rates of change independently is key to determining new markers for cardiovascular risk. circadian rhythm; male-female differences; logistic equation; heart rate AMBULATORY BLOOD PRESSURE (ABP) monitoring devices are now very widely used for detecting white coat hypertension, for adjusting drug therapy for hypertensive patients, as well as for predicting the level of hypertension-induced enlargement of the heart and thickening of the blood vessels (10). ABP recorders have also confirmed earlier findings by invasive methods that there is a clear diurnal pattern in blood pressure (BP). Values are highest in the morning, decrease gradually during the day, and reach the lowest values at night. Although the exact mechanisms for the rhythm are not yet fully understood, physical activity and periods of rest strongly influence the diurnal BP pattern (7).Known methods of analysis of circadian rhythms have generally involved averaging BP records at fixed clock times or synchronizing records relative to the time of waking. Thus the data are segmented into a higher pressure period, approximating the daytime awake period, and a low-pressure period corresponding to the nighttime sleep period. The difference in these two BP levels constitutes the major circadian variation in BP. However, this approach is rather limited, ...

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Section: Discussionsupporting

confidence: 90%

Nonsymmetrical double logistic analysis of ambulatory blood pressure recordings

Head

Reid

Лукошкова³

2005

Journal of Applied Physiology

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“…Files were recorded using ART acquisition (Data Sciences International, Minneapolis, MN) or Labview data acquisition. 36 …”

Section: Telemetrymentioning

confidence: 99%

Reduced Phosphoinositide 3-Kinase (p110α) Activation Increases the Susceptibility to Atrial Fibrillation

Pretorius

Woodcock

et al. 2009

The American Journal of Pathology

153

133

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Atrial fibrillation (AF) is the most common sustained arrhythmia presenting at cardiology departments. A limited understanding of the molecular mechanisms responsible for the development of AF has hindered treatment strategies. The purpose of this study was to assess whether reduced activation of phosphoinositide 3-kinase (PI3K, p110␣) makes the compromised heart susceptible to AF. Risk factors for AF, including aging, obesity, and diabetes, have been associated with insulin resistance that leads to depressed/defective PI3K signaling. However, to date, there has been no link between PI3K(p110␣) and AF. To address this question, we crossed a cardiac-specific transgenic mouse model of dilated cardiomyopathy (DCM) with a cardiac-specific transgenic mouse expressing a dominant negative mutant of PI3K (dnPI3K; reduces PI3K activity). Adult (ϳ4.5 months) double-transgenic (dnPI3K-DCM), single-transgenic (DCM-Tg, dnPI3K-Tg), and nontransgenic mice were subjected to morphological, functional/ECG, microarray, and biochemical analyses. dnPI3K-DCM mice developed AF and had depressed cardiac function as well as greater atrial enlargement and fibrosis than DCM-Tg mice. AF was not detected in other groups. Aged DCM-Tg mice (ϳ15 months) with a similar phenotype to dnPI3K-DCM mice (4.5 months) did not develop AF , suggesting loss of PI3K activity directly contributed to the AF phenotype. Furthermore, increasing PI3K activity reduced atrial fibrosis and improved cardiac conduction in DCM-Tg mice. Finally, in atrial appendages from patients with AF, PI3K activation was lower compared with tissue from patients in sinus rhythm. These results suggest a link between PI3K(p110␣) and AF. (Am J Pathol

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“…Um exemplo foi documentado no Britsh Heart Journal por meio de uma carta de Gerbes, Haen e Arbogast (1985) criticando o método estatístico utilizado por Davies (DAVIES et al, 1984) A elevação da pressão arterial em uma segunda fase do ciclo claro/escuro considerada por Gerbes et al como sendo erro de coleta, pode ser considerada um padrão ultradiano desse ritmo (VEGLIO et al, 1994;RABBIA et al, 1997;SCORZONI et al, 1997;HERMIDA et al, 2002;PEREZ-LLORET et at 2004;). Como forma de avaliar esse padrão ultradiano da pressão arterial, Head (2004) propõe o método duplo-logistico como forma de medir os componentes ultradianos apresentados pela pressão arterial e frequência cardíaca (HEAD et al, 2005). Esse método consiste em seis pontos (Figura 24); P1; momento de maior valor na curva durante a fase escura.…”

Section: Discussionunclassified

“…Representação da curva ajustada do método duplo-logístico para a dados de frequência cardíaca de um sujeito. Pontos escuros representam a fase escura e as claras a fase clara do ciclo claro/escuro Head et al (2004).…”

Section: Discussionunclassified

“…O método duplo-logístico tem sido utilizado em uma série de estudos (HEAD et al, 2005;HEAD et al, 2006;HEAD 2010HEAD et al, 2010, nos quais os autores demonstraram ser o método mais adequado tanto para comparações rítmicas em animais quanto em humanos, não vindo a ser um método que desqualifique o Cosinor, mas possivelmente o complemente (HEAD et al 2004;KATZ et al, 2012).…”

Non-symmetrical double-logistic analysis of 24-h blood pressure recordings in normotensive and hypertensive rats

Cited by 32 publications

References 22 publications

Nonsymmetrical double logistic analysis of ambulatory blood pressure recordings

Nonsymmetrical double logistic analysis of ambulatory blood pressure recordings

Reduced Phosphoinositide 3-Kinase (p110α) Activation Increases the Susceptibility to Atrial Fibrillation

Avaliação do efeito hipotensivo pós-exercício em diferentes fases do dia

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