Invited commentary: Hypertension and arterial stiffness - Origins remain a dilemma

In this issue of the Journal, Chen et al. (Am J Epidemiol. 2016;183(7):599-608) present repeated measures of aorto-femoral pulse wave velocity, capacitive compliance (C₁), and oscillatory compliance (C₂) in the Bogalusa Heart Study, with the purpose of addressing which comes first: blood pressure elevation or arterial stiffening. After an average follow-up period of 7 years (2000-2010), the authors found that blood pressure at a mean age of 36 years predicted change in arterial stiffening by a mean age of 43 years, but not the reverse. Essential hypertension results from a mosaic of pathological mechanisms. It has been theorized that biological pathways involving increased sympathetic tone, insulin resistance, renin-angiotensin-aldosterone activation, and inflammation lead to hyperkinetic circulation, volume overload, and vascular remodeling. The resultant accelerated vascular aging may be assessed by determining the degree of arterial stiffness. The findings of Chen et al. add important empirical information to the literature but do not solve the dilemma regarding the origins of essential hypertension, partly because there are many techniques for estimating the many aspects of arterial stiffness which are not fully understood. Mathematical features of estimates might not be uniform across the age range. There is a need for tracking blood pressure and different aspects of arterial stiffness from childhood onward, with an aim of preventing hypertension in adult life.