EXERCISE ACTIVATES RENAL DYSFUNCTION IN HYPERTENSION

A bilateral, exercise-mediated renal functional abnormality was first described more than a decade ago. The disturbance is specific for hype rtension, is seen in different forms of hypertension, and has been stu died most extensively in hypertensives with renovascular disease. The bilateral-abnormal exercise renogram identifies the disturbance. Hyper tensives with unilateral renovascular disease were studied in the cont inuing evaluation of the bilateral function disturbance. We examined 3 1 hypertensives with documented unilateral renovascular disease, all o f whom had renography at rest and during 60 to 80 W ergometric exercis e. An additional seven normotensives and 17 essential hypertensives se rved as controls, and had the same sequence of studies. All patients r eported upon continued on to an infusion clearance with I-131-hippurat e and In-111-diethylenetriamine pentaacetic acid to determine glomerul ar filtration rate (GFR) and effective renal plasma now (ERPF) at rest , and during 25 W ergometric exercise. Eighteen of 31 hypertensives wi th unilateral renovascular disease were found to have a bilateral-abno rmal exercise renogram. Clearance examinations in these identified a p rominent reduction of the GFR and a lesser decrease in the ERPF during exercise. Hypertensives with normal exercise renograms did not have t he exercise mediated abnormal clearance pattern. Similar results were observed in the control population of essential hypertensives, 65% of whom developed the functional disturbance. The seven normotensives con trols did not exhibit the exercise mediated function changes. We concl ude that an exercise-mediated bilaterally occuring functional disturba nce exists in certain hypertensives, who then have a bilateral-abnorma l exercise renogram. Associated with this is a distinctly abnormal cle arance during exercise which is characterized by a low filtration frac tion.