ESH 2007 Milan: New study shows renal protection in hypertensive patients with type 2 diabetes

(Jun. 2007) Today AMADEO™, one of the first studies to compare the protective potential of two angiotensin receptor blockers in hypertensive patients with diabetic nephropathy, was presented at the European Society of Hypertension, Milan. The results from this study show that telmisartan reduces proteinuria to a significantly greater extent than losartan.

Commenting on the results, Prof. Ellen Burgess, Foothills Hospital in Calgary, Canada said "The AMADEO™ results are encouraging for an increasing number of patients with type 2 diabetes because they suggest that telmisartan could improve renoprotection. It is particularly interesting that the observed effect was seen despite the study being controlled for blood pressure." She continued "Telmisartan has already shown superior blood pressure lowering compared to losartan and, in AMADEO™, patients were allowed to take other medication, if needed, to ensure similar blood pressure in both treatment groups. This suggests that the protective benefits seen with telmisartan here are an additional attribute beyond its established blood pressure lowering effects."

Diabetic nephropathy is a kidney disease that occurs approximately in one third of patients with diabetes mellitus 2. These study results could, therefore, have a positive impact on millions of type 2 diabetes patients as well as healthcare systems worldwide. The prevalence of diabetes is projected to increase at an alarming rate from 171 million in 2000 to 366 million by 2030, with the upsurge in obesity closely linked to increased type 2 diabetes. Over time, diabetic nephropathy can lead to end-stage renal disease, a serious condition that needs dialysis and increased medical care and resources. End-stage renal disease has tripled in prevalence over the past two decades4 and has huge associated healthcare costs, predicted to be US$28billion by 2010 in the US alone.

AMADEO™, a randomized, double-blind, forced-titration, parallel-group, multicentre study, included 860 hypertensive patients (>130/80mmHg) with type 2 diabetes and overt nephropathy from 124 centres in 10 countries. Patients were randomized to receive treatment with either telmisartan 80mg or losartan 100mg. To ensure BP control in the two patient groups other non-ARB treatments (hydrochlorothiazide or calcium channel blocker) were added, if needed.

After one year’s treatment, telmisartan was significantly more effective than losartan in reducing the amount of protein excreted in the urine. The primary end point of the study was reduced by 29% with telmisartan vs. 20% with losartan; p= 0.0284.

Telmisartan was superior to losartan on the primary endpoint, a change from baseline after 12 months (log transformed Urinary Protein creatinine ratio) of 0.71 (95% CI; 0.66, 0.77) vs. 0.80 (95% CI; 0.74, 0.87) for losartan; p=0.0284.

No significant difference in blood pressure control or number of adverse events was observed between the two treatments groups.

Proteinuria (high levels of protein in the urine) is a very important signal for disease severity in diabetic nephropathy and is also considered a relevant cardiovascular risk factor. Renal outcomes trials have shown that reductions of >30% at six months are strongly linked to slowed progression to end-stage kidney disease and reduced cardiovascular events.

AMADEO™ successfully concludes the series of PROTECTION^® studies which are part of an extensive ongoing trial programme, including clinical and observational studies, investigating the outstanding effects of telmisartan compared with other treatments for hypertension, including other available ARBs. The trials established the effects of telmisartan in providing powerful blood pressure reductions from morning to morning as well as organ-protective effects.

Telmisartan has a longer duration of action than all other members of the ARB class; it takes approximately 24 hours for half the dose of telmisartan to be eliminated from the body compared to five to 15 hours for other ARBs. Telmisartan is 99.5% bound to serum protein and is excreted almost entirely via non-renal pathways. Clinical trials have shown that telmisartan provides powerful and consistent blood pressure reduction over a full 24 hour period.