EXCESS INTERDIALYTIC WEIGHT-GAIN PROVOKES ANTIHYPERTENSIVE DRUG-THERAPY IN PATIENTS ON MAINTENANCE HEMODIALYSIS

We studied 90 randomly selected patients with end-stage renal disease (ESRD) on maintenance hemodialysis to determine the relationship betwe en interdialytic weight gain (IDWG) and a) predialysis blood pressure, b) the use of antihypertensive medication, and c) the presence of lef t ventricular hypertrophy (LVH) on electrocardiogram. IDWG was express ed as a percent of the patients' preceding postdialysis weight. We als o documented their predialysis blood pressure, number and dose of anti hypertensive medications, and presence of LVH on a standard 12-lead el ectrocardiogram. The mean age of the study subjects was 58 +/- 15 year s. The 43 men and 47 women included 61 blacks, 16 whites, 10 Hispanics , and 3 Asians. All patients received thrice-weekly conventional dialy sis using a modified cellulose acetate dialyzer. The mean IDWG was 4.2 +/- 1.2%. Twenty-one (23%) of the 90 patients had LVH documented on e lectrocardiogram, and 49 (54.4%) of the 90 patients were receiving at least one antihypertensive medication. The mean predialysis systolic b lood pressure was 144 +/- 15 mmHg, while the predialysis diastolic blo od pressure was 81 +/- 7.8 mmHg. IDWG correlated with predialysis syst olic blood pressure (r = 0.23, p = 0.029) and with predialysis diastol ic blood pressure (r = 0.21, p = 0.045). Subjects receiving two or mor e antihypertensive medications had a greater IDWG (5 +/- 1.36) than th ose receiving either one antihypertensive medication (4.3 +/- 1.04%) o r no antihypertensive medication (3.8 +/- 0.98% (p<0.05 by ANOVA). Mul tiple regression analysis revealed that of all the variables examined, IDWG was the only determinant of both predialysis systolic blood pres sure (p = 0.03) and use of antihypertensive medication (odds ratio = 1 .9, p = 0.002, 95% C.I. 1.72,2.09). The presence of LVH was determined by the duration of ESRD (odds ratio = 0.9846, p = 0.06, 95% C.I. = .9 837,.9855). We conclude that excess interdialytic weight gain in patie nts on maintenance hemodialysis is associated with increased predialys is blood pressure and provokes the use of antihypertensive medication.