The heterogeneity of vascular findings in the kidneys of patients with benign essential hypertension.

As the interlobular arteries of the ageing kidney progressively accumulate intimal fibroplasia, these fibroplastic changes appear to introduce strictures upon the interlobular arteries. These strictures are expected to generate nephron heterogeneity, which is a uniquely disturbed setting peculiarly suited to sustaining both high and low renin forms of hypertension. Fibroplastic renovasculopathy accumulates with age at varying rates in different human populations, and these rates closely parallel the rise of blood pressure with age, as documented by community surveys. Here, I introduce the expression type 1 for hypertension in subjects with mild or minimal renovasculopathy, and type 2 for those with severe vasculopathy. Data reviewed here imply that variations in prevailing blood pressure levels between populations can be attributed entirely, or almost entirely, to type 2 hypertension. No practical test is available to detect nephron heterogeneity clinically. Tests for this purpose have not been and are not now in development. The reason for this deficiency is probably the general lack of suspicion regarding the existence of this pathological entity. Once the entity becomes the target of attention, a variety of tests for measuring its severity in clinical patients should follow readily.