Overexpression of the renin-angiotensin system is important in the pathogenesis of macroangiopathy (MA). Patients with diabetes with end-stage renal failure have elevated serum angiotensin-converting enzyme (ACE) activity compared with their nonuremic counterparts. Because their major cause of death is MA, the significance of serum ACE activity on outcome of this group of patients is studied. We performed a prospective cohort study of 49 patients with type 2 diabetes on continuous ambulatory peritoneal dialysis (CAPD) therapy. Baseline serum ACE activity was determined by a modified spectrophotometric method and followed up at a median of 34 months. The prevalence of MA (defined as ischemic heart disease, sudden cardiac arrest, stroke, or peripheral vascular disease) and all-cause mortality rates were studied. Risk for MA is associated with serum ACE activity (median with MA, 69.0 U/L [range, 46.0 to 100.1 U/L] versus without MA, 57.2 U/L [range, 36.3 to 81.0 U/L]; P = 0.02). At the end of follow-up, 48% of patients (24 of 49 patients) died, 70% of MA. The group that died had increased baseline serum ACE activity (nonsurvivors, 65.0 U/L [range, 33.5 to 100.0 U/L] versus survivors, 49.4 U/L [range, 36.4 to 86.5 U/L]; P < 0.05) and MA rates (nonsurvivors, 77% versus survivors, 36%; P < 0.01). Cox regression analysis performed with age, sex, mean blood pressure, body mass index, metabolic control, Kt/V, residual renal function, serum albumin level, and ACE activity showed that baseline serum ACE activity (P = 0.033) is an independent predictor for mortality in patients with type 2 diabetes on CAPD therapy. Among patients with type 2 diabetes on CAPD therapy, serum ACE activity is associated with risk for MA and is an independent predictor for mortality. Whether ACE inhibition will have a beneficial effect on the outcome of these patients needs further investigation.
Copyright 2002 by the National Kidney Foundation, Inc.