• Change from baseline (Visit 6) in 24 hour proteinuria, after one year of treatment (study end) with telmisartan 80 mg versus valsartan 160 mg.
  

• Change from baseline in 24 hour albuminuria, creatinine clearance, estimated GFR, serum creatinine, 24 hour sodium excretion, ADMA, 8-iso-prostaglandin F2a, hs CRP, doubling of serum creatinine, composite of cardiovascular morbidity and mortality.
  

This is a randomised, double-blind, double-dummy, forced titration, multicentre, parallel group trial in patients with essential hypertension, diabetes mellitus type 2 and diabetic nephropathy.

After a 4-6 week Run-in period, patients are randomised to one of the treatment groups and receive either Telmisartan 40 - 80 mg or Valsartan 80 - 160 mg. The treatment regimen is a forced titration with the lower dose given for 2 weeks and the higher dose given for the rest of the treatment period summing up to 52 weeks of treatment. During the treatment period, 8 visits to the investigator are scheduled in order to control blood pressure, renal function parameters and safety. In addition, parameters of endothelial function and oxidative stress are measured at baseline, 6 months and after one year of treatment.

Study Hypothesis:

Non-inferiority of telmisartan 80 mg compared to valsartan 160 mg will be tested using the following set of hypotheses:

Null Hypothesis:

The overall mean change from baseline in UPER (24 hour urinary protein excretion rate) for telmisartan 80 mg is inferior to that for valsartan 160 mg by 0.5 g/day or more.

Alternative Hypothesis:

The overall mean change from baseline in UPER (24 hour urinary protein excretion rate) for telmisartan 80 mg is less than 0.5 g/day worse than that for valsartan 160 mg.

Comparison(s):

In order to test the non-inferiority hypothesis, analysis of covariance with treatment and centre as main effects and baseline as a covariate will be performed. Time-to-event data will be analysed using the log-rank test.