Nonsymmetrical double logistic analysis of ambulatory blood pressure recordings

Abstract

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, ...

Misclassification and discordance of measured blood pressure from patient’s true blood pressure in current clinical practice: a clinical trial simulation case study

“…Several other models were also available in the literature to describe the daily based variability of BP. Some models focused on the BP deference between daytime and nighttime BP such as the square wave fit model [27], some model focused on the transit phase between day time and night-time BP changes such as double logistic model [20,28,29]. The limitation of these models is the lack of description of the important features regarding BP fluctuations.…”

Response to "Analysis and Interpretation of 24-h Blood Pressure Profiles"

“…7 Thus each parameter signifies an important characteristic of the circadian cardiovascular profile. This method can best predict the path of the blood pressure during the rising phase, independent of other times of the day, and independent of how long it takes.…”

“…It has been suggested that this method constrains the pattern to a particular shape, but this assumption is not correct. The flexibility and independence of the parameters allows for the pattern to follow a single symmetrical cosine function, a saw tooth shape in either direction as well as a square wave-like shape (see Figure 1 of Head et al 7 ). This method, however, does not allow us to follow complex fluctuations within the plateaus as can the 4-or-moreelement Fourier method.…”

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

“…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.…”

“…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).…”