ISOLATED SYSTOLIC HYPERTENSION IN UREMIC PATIENTS ON HEMODIALYSIS

Prevalence of Isolated Systolic Hypertension (ISH) defined as systolic blood pressure > 160 mmHg and diastolic blood pressure < 90 mmHg was studied in a population of 148 patients treated by hemodialysis whose 80 had undergone ambulatory blood pressure (ABP) recording during the interdialytic period. All patients were treated 3 times 4 hours a week. ABP was recorded for 48 hours between two sessions of hemodialysis using a Delmar Avionic Presurometer (PIV). Prevalence of ISH was 12.5 %, while that of systolic-diastolic hypertension (SDH) was 15 %. Average age at the time of the study was respectively 59 +/- 13 yrs ISH and 49 +/- 11 yrs SDH (p < 0.01) while that of patients with normal blood pressure (N) was 57 +/- 10 yrs. Mean duration of HD treatment was no different between groups: 5.3 +/- 3.5 yrs ISH, 5.0 +/- 4.2 yrs SDH and 5.0 +/- 4.3 yrs N. Causes of end-stage renal disease were similar in each group. All patients with ISH and SDH and 42 % of N pts were receiving antihypertensive treatment at the time of ABP recording. Finally, level of anemia and percentage of patients treated by EPO were similar in each group. Prevalence of arteriosclerosis obliterans of the lower limbs was significantly higher in ISH group (70 %) than in N group (15 %) and SDH group (16 %) (p < 0.01), ABP recording during intra and interdialytic period showed that: ISH was always present at the end of HD session despite efficient ultrafiltration; ISH was sustained during interdialytic period despite antihypertensive drugs; half of patients with ISH had lost circadian rhythm vs 36 % in N patients and 40 % in SDH patients; finally, frequency of severe hyperparathyroidism was significantly higher in ISH group than N group (X2 = 7.2 ; p > 0.01). We conclude that isolated systolic hypertension in uremic patients is: not related to age, duration of HD, level of anemia and treatment by EPO; significantly related to arteriosclerosis obliterans of the lower limbs and severe hyperparathyroidism; not improved by ultrafiltration and antihypertensive treatment.