SYMPATHETIC SKIN-RESPONSE AND R-R INTERVAL VARIATION IN CHRONIC UREMIC PATIENTS

Sympathetic skin response (SSR) and R-R interval Variation (RRIV) were studied in 36 chronic, nondiabetic uremics to compare with their nerv e conduction studies (NCS) and clinical dysautonomia. Abnormal SSR was noted in 5 (13.9%) patients, abnormal RRIV in 14 (38.9%), and abnorma l NCS in 26 (72.2%). The patients were classified into three groups: g roup (GP) 1: ''normal,'' n = 21 (58.3%), normal RRIV and SSR; GP 2: '' isolated parasympathetic dysfunction,'' n = 10 (27.8%), abnormal RRIV and normal SSR; and GP 3: ''sympathetic sudomotor dysfunction,'' n = 5 (13.9%), abnormal SSR. A significant difference in age was found amon g the three groups (GP 3 > GP 2 > GP 1; P < 0.0001, ANOVA). After cont rolling the age factor, we still noted a tendency toward increasing NC S disturbances (distal latency and nerve conduction velocity of perone al nerve; P < 0.05, multiple regression analysis) and frequencies of c linical autonomic symptoms (postural dizziness and impotence; P < 0.05 , Mantet-Hanszel test) from GP 1 to GP 3. Patients with abnormal SSR ( GP 3) displayed significantly higher frequencies of postural dizziness and impotence, indicating the relationship between an absence of SSR and clinical dysautonomia. (C) 1994 John Wiley and Sons, Inc.