The hidden hand of chloride in hypertension

Among the environmental factors that affect blood pressure, dietary sodium chloride has been studied the most, and there is general consensus that increased sodium chloride intake increases blood pressure. There is accruing evidence that chloride may have a role in blood pressure regulation which may perhaps be even more important than that of Na+. Though more than 85 % of Na+ is consumed as sodium chloride, there is evidence that Na+ and Cl- concentrations do not go necessarily hand in hand since they may originate from different sources. Hence, elucidating the role of Cl- as an independent player in blood pressure regulation will have clinical and public health implications in addition to advancing our understanding of electrolyte-mediated blood pressure regulation. In this review, we describe the evidence that support an independent role for Cl- on hypertension and cardiovascular health.