A 2011 meta-analysis of 5 RCTs (total 2975 patients) that compared ACE inhibitor therapy with placebo in diabetic patients without hypertension and albuminuria found that ACE inhibitors reduced the risk of new-onset microalbuminuria or macroalbuminuria by 18% (relative risk [RR]=0.82; 95% confidence interval [CI], 0.73-0.92).1 Normal albuminuria was defined in all included studies as an albumin excretion rate of <30 mg/d on a timed specimen confirmed with 3 serial measurements.
The RCTs included patients treated with lisinopril, enalapril, and perindopril. All but one examined patients with type 1 diabetes (2781 patients). The study that evaluated type 2 diabetes (194 patients) assessed patients with hypertension who used other antihypertensives to achieve normal blood pressure targets before ACE inhibitor initiation, a potential limitation.
Compared with placebo or no treatment, ACE inhibitor therapy reduced the risk of death from any cause (6 studies; 11,350 patients; RR=0.84; 95% CI, 0.73-0.97).1 Patient populations across pooled RCTs were heterogeneous, including subjects with type 1 and type 2 diabetes, with or without hypertension, and with or without albuminuria.
ACE inhibitors increase risk of cough
Patients taking an ACE inhibitor have an increased risk of cough (6 studies; 11,791 patients; RR=1.84; 95% CI, 1.24-2.72).1 ACE inhibitor therapy doesn’t increase the risk of headache or hyperkalemia.
ARBs don’t help prevent diabetic kidney disease in normotensive patients
The 2011 meta-analysis also included 5 RCTs (4604 patients, approximately 3000 with type 2 diabetes and more than 1000 with type 1 diabetes) that compared ARBs with placebo in patients without hypertension.1 Unlike ACE inhibitor therapy, ARB treatment didn’t significantly affect new-onset microalbuminuria or macroalbuminuria (RR=1.06; 95% CI, 0.67-1.69).
The trials evaluated losartan, candesartan, olmesartan, and valsartan. One study used other antihypertensives to achieve target blood pressure, and another included patients of any albuminuria status.
Compared with placebo or no treatment, ARBs didn’t reduce the risk of death (5 studies; 7653 patients; RR=1.12; 95% CI, 0.88-1.41).1 All 5 RCTs assessed normoalbuminuric patients. Three of the 5 studies examined normotensive patients; one evaluated only hypertensive patients, and another assessed mostly hypertensive patients.
ARBs usually don’t produce significant adverse effects
Within the meta-analysis, ARBs didn’t increase risk of cough, headache, or hyperkalemia.1