Background: The aim of this study was to assess whether carotid intima-media thickness (IMT) is more strongly associated with home-measured blood pressure (BP) than clinic BP. Other risk factors associated with carotid atherosclerosis were also investigated.
Methods: We studied a representative unselected sample of the Finnish adult population (758 subjects aged 45-74 years). Subjects included in the study underwent a clinical interview, carotid ultrasonography, and measurement of clinic BP (mean of two measurements using a mercury sphygmomanometer) and home BP (mean of 14 duplicate measurements during 1 week using a validated, automatic device). Fasting blood samples for serum lipids and glucose were drawn.
Results: The Pearson correlation coefficients for carotid IMT and home/clinic BP differed significantly in favour of home measurement for systolic BP (0.34 versus 0.25, P < 0.001), diastolic BP (0.20 versus 0.07, P < 0.001) and pulse pressure (0.37 versus 0.27, P < 0.001). In a linear regression model (R = 0.32, P < 0.001), age (P < 0.001), home systolic BP (P = 0.002), serum triglycerides (P = 0.006), male sex (P = 0.009), smoking (P = 0.017), diabetes (P = 0.035), and low-density lipoprotein cholesterol (P = 0.041) were independently associated with increased IMT. The association between home BP and carotid IMT did not increase with the number of home measurements.
Conclusion: BP is one of the most important factors in the pathogenesis of atherosclerosis. Home-measured BP is more strongly associated with carotid atherosclerosis than clinic BP, even for a low number of measurements. These data support the application of home BP measurement in clinical practice.