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CIRCADIAN-INFRADIAN INTERACTIONS OF BLOOD PRESSURE AND HEART RATE IN TREATED HYPERTENSIVE PATIENTS
Germaine Cornelissen, Franz Halberg, Tamara Breus, A.L. Miyasnikov, Agarwal Rajesh K.
Aim. To compare the time structure of daily casual measurements taken in the morning and in the evening.
Materials and methods. For about 3 months in 2001-2003, 32 patients at Myasnikov's cardiological center in Moscow, measured their blood pressure (BP) and heart rate (HR) manually once in the morning and once in the evening. All patients were treated for hypertension with indapamide alone or in combination with perindopril. On the average, records spanned 106.7 ± 25.3 days (mean ± SD). Morning and evening data from each patient were analyzed separately by the extended cosinor method. Specifically, periodograms were computed in the frequency range of one cycle in 84 days (12 weeks or ~ 3 months) to one cycle in 2.4 days (35 harmonic terms). Results were further summarized across all patients by population-mean cosinor.
Results. By population-mean cosinor, statistically significant components (P<0.05) found to characterize evening measurements of systolic (S) BP include a 2-week cycle (P=0.026), a desynchronized circaseptan rhythm with a period of about 6.5 days (P=0.040), and a prominent half-week variation (P=0.001) (P-values not corrected for multiple testing). The circaseptan (P=0.046) and half-week (P=0.036) components are also detected in evening measurements of diastolic (D) BP. In evening measurements of HR, the 2-week component is also prominently detected (P=0.007), whereas the month (4-week) (P=0.075) and the 6.5-day circaseptan component (P=0.088) only reach borderline statistical significance, the latter also corresponding to a spectral peak, suggesting that it involves more than merely phase synchronization. Apart from a monthly variation in HR (P=0.023), components detected in evening measurements are not found in the morning values. Discussion. Results indicate a clear difference in spectral structure between morning and evening BP and HR measurements, attesting not only to the presence of an important circadian variation, but also of interactions between the circadian and infradian changes in BP and HR. Differences are also found between the spectral structure of SBP and DBP on the one hand and that of HR on the other hand, providing further evidence for the different behavior of these two variables. The larger prominence of the half-week versus the circaseptan variation in BP observed in this study is in keeping with similar results found earlier in data from the Czech Republic, India, Japan and Minnesota. Apart from providing vital information regarding treatment efficacy in treated hypertensive patients, long-term BP and HR surveillance also offers a unique opportunity to study the effect of natural physical environmental factors from near and far on important physiological variables.
Материалы IX международного конгресса «Здоровье и образование в XXI веке» РУДН, Москва
Стр. [633]
