Role of vascular adaptation in determining systolic BP in young adults

Abstract

Background: Two individuals can have a similar pulse pressure (PP) but very different levels of systolic blood pressure (SBP), although the underlying mechanisms have not been described. We hypothesised that, for a given level of PP, differences in SBP relate to peripheral vascular resistance (PVR) and we tested this hypothesis in a large cohort of healthy young adults. Methods and Results: Demographic, biochemical and haemodynamic data from 3103 subjects were available for the current analyses. In both males and females, for a given level of PP, higher SBP was associated with significantly higher body weight, body mass index, heart rate and PVR (P<0.05 versus those with lower BP for all comparisons). Moreover, stratifying individuals by quartiles of PP and PVR revealed a stepwise increase in SBP from the lowest to highest quartile for each variable, with the highest SBP occurring in those in the highest quartile of both PP and PVR (P<0.001 for overall trend for both sexes). PVR was also increased with increasing tertile of minimum forearm vascular resistance, in both males (P=0.002) and females (P=0.03). Conclusion: Increased PVR, mediated in part through altered resistance vessel structure, strongly associates with the elevation of SBP for a given level of PP in young adults. An impaired ability to adapt PVR appropriately to a given level of PP may be an important mechanism underlying elevated SBP in young adults.