Renal protection with angiotensin receptor blockers: where do we stand?

The increasing burden on health care providers from chronic kidney disease (CKD) is due to the escalating prevalence of obesity, hypertension and type 2 diabetes. The gradual decline in kidney function in the presence of these risk factors is also associated with increased cardiovascular disease. Excess angiotensin II production by the renin-angiotensin system is responsible, at least in part, for development of hypertension and for damage in the kidneys and the cardiovascular system. Pharmacological targeting of the renin-angiotensin system not only reduces blood pressure, but may also provides more direct vascular protection. Angiotensin receptor blockers (ARBs) are better tolerated than angiotensin-converting enzyme inhibitors and, thus, may be a more practical therapeutic option. Clinical studies have demonstrated the efficacy of irbesartan, losartan, telmisartan and valsartan in the management of CKD. All ARBs tested to date have proved effective in improving at least some aspects of renal dysfunction. Few within-class comparative studies exist. Telmisartan provides superior reductions in proteinuria to losartan, however, even when blood pressures are equalized with concomitant antihypertensives. This superiority is probably linked to higher receptor affinity, longer plasma half-life and higher lipophilicity of telmisartan compared with other ARBs. The reduction of proteinuria with ARBs is also linked to improved cardiovascular outcomes. After a decade of research, there is now substantial evidence to show that the use of ARBs provides an efficacious treatment option for the prevention of renal disease progression in patients with hypertension and/or diabetes.