LB02.03: EVALUATION OF DAY-BY-DAY BLOOD PRESSURE VARIABILITY IN CLINIC (DO WE STILL NEED STANDARD DEVIATION?). (June 2015)

• Record Type: Journal Article
• Authors: Ryuzaki, M.; Nakamoto, H.; Hosoya, K.; Komatsu, M.; Hibino, Y.
• Is Part Of: Journal of hypertension. Volume 33(2015)Supplement 1
• Publication Date: 2015-06
• Subjects: Hypertension -- Periodicals; Hypertension -- Periodicals; 616.132005
• DOI: 10.1097/01.hjh.0000467581.27993.39
• Languages: English
• ISSNs: 1473-5598

Abstract

Abstract : Objective: Blood pressure (BP) variability correlates with cardio-vascular disease as BP level itself. There is not known easy way to evaluate the BP variability in clinic. To evaluate the usefulness of maximum-minimum difference (MMD) of BP in a month compared to standard deviation (SD), as an index of BP variability. Design and method: Study-1: Twelve patients (age 65.9 ± 12.1 y/o) were enrolled. Measurements of home systolic (S) BP were required in the morning. The 12 months consecutive data and at least 3 times measurements a month were required for including. (Mean 29.0 ± 4.5 times/month in the morning). We checked the correlation between MMD and SD. Study-2: Six hemodialized patients monitored with i-TECHO system (J of Hypertens 2007: 25: 2353–2358) for longer than one year were analyzed. As in study-1, we analyzed the correlation between SD and MMD of SBP. Measurements: 17.4 ± 11.9 times per month. Study-3: The data from our previous study (FUJIYAM study Clin. Exp Hypertens 2014: 36:508–16) were extracted. 1524 patient-month morning BP data were calculated as in study-1. Picking up data measuring more than 24 times a month, 517 patient-month BP data were analyzed. We compared the ratio to 25 times measured data of SD and MMD, in the setting 5, 10, 15, 20 times measured data. Results: Study-1: SBP, MMD was correlated very well to SD (p < 0.0001, R=0.923). Equation of SBPSD = 1.275+ 0.208xMMD. Study-2: R = 0.884 (P < 0.0001) SBPSD = 2.17+ 0.22xMMD. Study-3: R = 0.842(P < 0.0001), if we used all data measurements > 2 times. If data were extracted (measurements>24 times), correlation was 0.927 (P < 0.0001). The equation of SBPSD = 1.520+ 0.201xMMD. The ratios of SD to 25 times were as follows; 0.956 in 5 times, 0.956 in 10, 0.979 in 15, 0.991 in 20 times. The ratios of MMD to 25 times were as follows; 0.558 in 5, 0.761 in 10, 0.874 in 15, 0.944 in 20. Conclusions: We can assume SD easily by measuring MMD as an index of day-by-day BP variability of a month. The equation formulas were very similar though the patients' groups were different. But we have to be careful how many times patients measure in a month.