REN and Hypertension: Specifically, the guidelines endorse the view that there is a higher prevalence of low-renin hypertension in individuals of African ancestry or Black ethnic backgrounds (Materson 2007, Gupta et al. 2010), attenuating response to beta-blockers and angiotensin-converting enzyme inhibitors (which work primarily by suppressing the renin–angiotensin system) and increasing the likelihood of response to calcium channel blockers (which work primarily by vasodilation).