| Summary: | Background. No longitudinal study addressed whether systolic blood pressure level (SBPL) or variability (SBPV) predict arterial properties or vice versa.
Methods and Results. In families randomly recruited from a Flemish population, we determined SBPL and SBPV from 5 consecutive blood pressure readings. The indexes of SBPv were variability independent of mean (VIM), the difference between maximum and minimum SBPL (MMD), and average real variability (ARV). We measured carotid intima-media thickness (cIMT) and distensibility (cD) by ultrasound and carotid-femoral pulse wave velocity (cfPWV) by tonometry (SphygmoCor, version 8.2). Effect sizes were computed for 1 SD increments in the predictors, while accounting for covariables and family clusters. Among 1171 participants (51.0% women; mean age, 39.8 years), followed up for 2.48 years (median), higher SBPL predicted (P≤0.036) higher cIMT (+14 μm), lower cD (–1.57 10-3/kPa) and faster cfPWV (+0.298 m/s) at follow-up, whereas none of the SBPV indexes predicted the arterial traits at follow-up (P≥0.11). In a subset of 749 participants, followed up for another 3.07 years, lower cD predicted (P≤0.026) higher SBPL (+1.69 mm Hg), VIM (+0.304 units), MMD (+1.05 mm Hg) and ARV (+0.389). Higher cfPWV predicted a 1.06 mm Hg increase SBPL (P = 0.027).
Conclusions. Temporality and effect size suggest that SBPL but not SBPV cause arterial stiffening and cIMT thickening. Carotid stiffening, independent of SBPL, predicts SBPV, possibly because baroreflexes originating from a stiffer carotid artery wall are impaired. Finally, stiffening of the aorta contributes to the age-related SBPL possibly because faster returning reflected waves augments SBPL.
Figure 1Flow chart of participants1.
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