Measurement of trough-to-peak ratios of four antihypertensive drugs on the basis of 24-H ambulatory blood pressure monitoring. Different methods may give different results.

The use of Fourier analysis in the calculation of trough to peak ratio from ambulatory blood pressure measurements

“…length of this interval and the number of data points needed to reliably estimate the trough effect are usually not specified. 3,5 The mean trough responses during the last 2 h of the dose interval were similar after TBA and smoothing by FA (TBA: −12.8 (±2.0); FA: −12.8 (±1.8) mm Hg). In contrast to BP changes at peak, the mean and median BP changes at trough, obtained by either method of analysis, were practically identical (TBA: median −11.5 (PI, −34.6 to 7.4); FA: median −12.5 (PI, −32.8 to 5.6) mm Hg), indicating a normal distribution.…”

“…The same may also occur with TBA if an inappropriately long averaging interval is chosen. 5,7 Another way to minimise the influence of outliers is to increase the length of the period during which the peak effect is evaluated. Zanchetti et al 3 have described various ways in which the peak effect can be determined from 24-h ambulatory BP data.…”

“…[2][3][4][5][6] In consequence, values for T:P ratios reported for the same drug vary greatly according to the method of calculation. [7][8][9][10] BP is subject to short-lived fluctuations, linked to factors such as physical activity, mental stress and meal times.…”

Lisinopril versus enalapril: evaluation of trough:peak ratio by ambulatory blood pressure monitoring

“…6 This rather arbitrary limit seems meaningless, however, unless the method by which the T:P ratio of a drug is determined is specified. 15,[17][18][19][20][21][22] In the last years, many excellent reviews addressing the methodology of T:P ratio assessment, especially from 24-h ABPM data, have been published. [15][16][17][18][19]21,22 In these papers, many recommendations have been made for calculation of T:P ratios.…”

“…15,[17][18][19][20][21][22] In the last years, many excellent reviews addressing the methodology of T:P ratio assessment, especially from 24-h ABPM data, have been published. [15][16][17][18][19]21,22 In these papers, many recommendations have been made for calculation of T:P ratios. Not only do these guidelines need validation in prospective studies, but also the value of the T:P ratio as an index of 24-h BP control still needs to be established, as there are no prospective studies showing a relation between T:P ratio and target organ damage.…”