Increased Serum Angiotensin-Converting Enzyme in End-Stage Renal Disease

K.W. Rumpf, MD, Department of Nephrology, University Hospital, Robert-Koch-Strasse 40, D-3400 Göttingen (FRG) Dear Sir, We read with interest the article by Silver stein et al. [1] concerning serum angiotensinconverting enzyme (SACE) activities in patients with renal disease. Contradictory results have been published on this topic in the past [2–5]. We would like to communicate our own data relating to SACE in 34 patients with end-stage renal failure on maintenance hemodialysis treatment. These data partially confirm the results of Silverstein et al. [1]. Moreover, they may give some insight into the mechanisms underlying the increase of SACE of this patient population. Our results are given in table I. It may be seen that in the patient group as a whole SACE [6,7] was significantly (t = 3.0898; p < 0.005) elevated as compared to normal controls. This is consistent with the findings of Silverstein et al. [1] and earlier results of Patel and Ansari↓l↑. Our group of 34 hemodialysis patients had been especially selected to comprise 20 patients with consistent hypotension (predialysis systolic blood pressure value consistently < 100 mm Hg). Further analysis of our data showed that SACE was significantly (t = 3.4539; p < 0.005) elevated in the hypotensive patient group only, whereas in the hypertensive/normotensive patient group only a slight elevation of SACE of borderline significance (t = 2.0367; p = 0.055) was detected. This finding is similar but not identical to the results of Silverstein et al. [1], who found elevated SACE activities in patients with low postdialysis blood pressure. Since some of our patients had evidence of liver disease (serological evidence of hepatitis B, alcoholic liver disease, or slightly elevated transaminase activities of unknown origin) – a situation in which increased SACE activities have been described 1 Supported by Deutsche Forschungsgemeinschaft (SFB-89-Kardiologie). Table I. Serum angiotensin-converting enzyme (SACE) activity in patients with end-stage renal failure on maintenance hemodialysis and in normal control (mean ± SD)