Effects of valsartan, benazepril and their combination in overt nephropathy of type 2 diabetes: A prospective, randomized, controlled trial

AIMS

To evaluate whether angiotensin-converting enzyme (ACE) inhibitor and angiotensin II receptor blocker (ARB) combination therapy is more nephroprotective than ACE inhibitor or ARB monotherapy in people with type 2 diabetes and overt nephropathy.

MATERIALS AND METHODS

In this prospective, randomized, open, blind-endpoint phase III trial sponsored by the Italian Drug Agency, 103 consenting patients with type 2 diabetes, aged >40 years, with serum creatinine levels 159 to 309 μmol/L, spot morning urinary albumin-creatinine ratio > 1000 mg/g (or > 500 mg/g in those on ACE inhibitor or ARB therapy at inclusion) were stratified by centre and randomized to 4.5-year treatment with valsartan 320 mg/d (n = 36), benazepril 20 mg/d (n = 34) or halved doses of both medications (n = 33). The primary endpoint was end-stage renal disease (ESRD). Modified intention-to-treat analyses were performed.

RESULTS

Recruitment took place between June 2007 and February 2013 at 10 centres in Italy and one in Slovenia. A total of 77 participants completed the study and 26 were prematurely withdrawn. During a median (interquartile range) of 41 (18-54) months, 12 participants on benazepril (35.3%) and nine on combination therapy (27.3%) progressed to ESRD, versus five on valsartan (13.9%). Differences between benazepril (hazard ratio [HR] 3.59, 95% confidence interval [CI] 1.25-10.30; P = 0.018) or combination therapy (HR 3.28, 95% CI 1.07-10.0; P = 0.038) and valsartan were significant, even after adjustment for age, gender and baseline serum creatinine, systolic blood pressure and 24-hour proteinuria (HR 5.16, 95% CI 1.50-17.75, P = 0.009 and HR 4.75, 95% CI 1.01-22.39, P = 0.049, respectively). Adverse events were distributed similarly among the groups.

CONCLUSIONS

In people with type 2 diabetes with nephropathy, valsartan (320 mg/d) safely postponed ESRD more effectively than benazepril (20 mg/d) or than halved doses of both medications.

Cardiovascular disease: what's all the AGE/RAGE about?

Advanced glycation end-products (AGEs) are involved in mediating the effects of hyperglycaemia in diabetes. The most important receptor for AGEs is the receptor for advanced glycation end-products (RAGE). Binding of AGEs to RAGE converts transient cellular stimulation into sustained cellular dysfunction driven by long-term activation of the pro-inflammatory transcription factor NF-kB. Different splice variants of RAGE exist, including a soluble form that binds to AGEs but lacks the intracellular domain and thus fails to induce signal transduction. In this context, soluble RAGE may act as a therapeutic agent for AGE-induced effects. The balance between the synthesis of sRAGE and full-length RAGE may be an important determinant of AGE-induced dysfunction. An increasing amount of evidence suggests that AGEs either directly or via their interaction with RAGE play a pivotal role in the development and acceleration of atherosclerotic cardiovascular disease. These effects will be summarised in this review, together with the effects of therapeutic strategies targeting AGE/RAGE interactions. These treatments appear to have significant clinical potential, most likely in combination with currently used agents such as inhibitors of the renin-angiotensin system or statins, to reduce the major burden of diabetes, its associated cardiovascular disease.