Is there increased cardiovascular risk in essential hypertensive patients with abnormal kinetics of red blood cell sodium???lithium countertransport?

Na + transport kinetics were studied in red blood cells (RBCs) from 50 essential hypertensive patients and 30 normotensive controls. Seven hypertensive patients were characterized by the following: 1) a maximal rate of Na + −Li + countertransport higher than an upper normal limit of 525 μmol.litre cells −1 .h −1 ; 2) an apparent dissociation constant for internal Na + higher than an upper normal limit of 20.4 mmol.litre cells (in only five of the seven hypertensives); 3) no other kinetic abnormality in Na + , K + pump, Na + , K + cotransport or passive Na + permeability