title: Potassium: weighing the evidence for supplementation.
abstract: Changes in potassium levels clearly have hemodynamic significance. In mechanistic terms, they affect the transmembrane potential of vascular smooth muscle cells. They also influence the levels and activity of pressor hormones and of intracellular messengers involved in vasoconstriction. Furthermore, they alter the body's handling of sodium. As the net result, perhaps, of these phenomena, chronic supplementation of dietary potassium is associated with a small but appreciable decline in blood pressure. In humans, the effect, which could be predicted epidemiologically, has been demonstrated in studies of potassium administration in hypertensive patients. In experimental animals, the effect is most pronounced in salt-sensitive models of hypertension. The studies done to date do not permit firm recommendations about modification of dietary potassium content for hypertensive patients. However, in certain clinical settings, potassium repletion even for mildly depressed levels is vitally important, and in other circumstances, excess potassium clearly is dangerous. Still, indications are emerging that potassium may be valuable in preventing renal damage and stroke, quite apart from any effect on hypertension itself. Continued investigation will be of great value in the effort to arrive at a firm understanding of the precise roles that potassium may play in the treatment of hypertension or the prevention of its sequelae.
mesh_terms: D000818:Animals; D002463:Cell Membrane Permeability / Q000187:drug effects; D004231:Diuresis / Q000187:drug effects; D005069:Evaluation Studies as Topic; D005527:Food, Fortified; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D006973:Hypertension / Q000188:drug therapy* / Q000378:metabolism / Q000517:prevention & control; D009131:Muscle, Smooth, Vascular / Q000187:drug effects; D011188:Potassium / Q000008:administration & dosage* / Q000097:blood / Q000378:metabolism; D014661:Vasoconstriction / Q000187:drug effects; D014664:Vasodilation / Q000187:drug effects
chemical_list: D011188:Potassium