Isolated Systolic Hypertension in Young Individuals: Pathophysiological Mechanisms, Prognostic Significance, and Clinical Implications.

Isolated systolic hypertension (ISH) is the most common form of hypertension in older persons and its predictive value for adverse outcome is well known. However, ISH can be frequently found also in young individuals, especially among males, but its prognostic significance in this setting is still controversial. Increased large artery stiffness is the main determinant of ISH in elderly patients whereas the mechanisms that lead to ISH in the young are still debated. According to some authors ISH in youth is a totally benign condition that can be called "spurious hypertension" a phenomenon due to enhanced pulse pressure amplification of the pulse wave from central to peripheral sites. According to others the main determinant of ISH in young individuals is increased sympathetic activity and the consequent hyperkinetic state characterized by elevated heart rate and stroke volume. This phenomenon is often amplified by a powerful alarm reaction to the medical visit. However, recent research has shown that ISH in the young is a heterogeneous condition and that in some individuals also increased arterial stiffness can play a role. Although ISH seems to be a benign condition chiefly in young men, only few longitudinal data assessing the association with adverse outcomes are available. Future studies with long term follow-up are needed to better understand the clinical significance of this condition.