Abstract P184: Is Home Blood Pressure More Strongly Associated with Coronary Artery Calcification Than Clinic Blood Pressure Measured Under an Appropriate Condition?

Abstract

Background / Objective: A number of studies have shown that home blood pressure (HBP) is more strongly associated with atherosclerotic diseases than clinic blood pressure (CBP). In previous studies, however, measurement of CBP under suboptimal conditions might have undermined the usefulness of CBP for prediction of atherosclerotic diseases. Therefore, we conducted a cross-sectional analysis to clarify whether HBP is more strongly associated with coronary artery calcification (CAC) than strictly measured CBP among a general population of Japanese men. Methods: From 2006 to 2008, we recruited 1094 male participants randomly selected from the residents in Kusatsu City, Shiga, Japan. CBP was measured twice consecutively by a trained physician using electrical device after 5 minutes of complete rest in a sitting position in a silent room. The participants were asked to measure HBP with an electrical device once in the morning during the consecutive 7 days. HBP was measured in seated position after 2 minutes of rest, within an hour after waking up, after urination and before breakfast. The mean of 2 measurements of CBP and the mean of 7 days of HBP were used in the analysis. CAC was assessed using computed tomography. Presence of CAC was defined as Agatston score >10. After exclusion of 175 participants with missing data on HBP, CBP, or CAC, a total of 919 people were included into the present analysis. We calculated multivariable-adjusted odds ratios (ORs) for presence of CAC per one standard deviation (SD) increase of CBP and HBP, then compared by adding interaction terms to the statistical model. ORs were adjusted for age, body mass index, history of cardiovascular diseases, smoking, ethanol consumption, blood sugar, serum total cholesterol, high density lipoprotein cholesterol, and use of medication (hypertension, dyslipidemia, and diabetes mellitus). Results: The mean systolic CBP (SD) and HBP (SD) were 136.8 (19.0) mmHg and 137.2 (18.5) mmHg, respectively. CBP and HBP were highly correlated (r = 0.74 P <0.001). The difference between CBP and HBP was not significant (P = 0.595). CAC was found in 454 (49.4%) participants. Multivariable-adjusted ORs (95% confidence interval) for presence of CAC were comparable between CBP (1.34 (1.14 - 1.58) per 1SD increase) and HBP (1.37 (1.16 - 1.62) per 1SD increase) (P heterogeneity = 0.819). When mean value of the first 2 days of HBP was used as a sensitivity analysis, we found almost the same results (P heterogeneity = 0.992). Similar results were also obtained for diastolic CBP and HBP (P heterogeneity = 0.968 for 7 days of HBP, 0.566 for 2 days of HBP). Conclusion: In conclusion, the association of CBP measured in an ideal condition with CAC was comparable with that of HBP.