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Letter to the editor
Editor, – I refer to the article 'Hypertension in diabetes' (Aust Prescr 2002;25:8-10).
The author suggests that while AT1 receptor antagonists may have the same benefits as ACE inhibitors, this has yet to be shown in clinical trials. I would draw your attention to the recently published PRIME program,1,2 which evaluated the effects of irbesartan on morbidity and/or mortality in patients with hypertension and type 2 diabetes across the continuum of early and advanced stages of diabetic renal disease.
The PRIME program consisted of two trials, IRMA 2 and IDNT.
In IRMA 2, the irbesartan 300 mg group demonstrated a 70% relative risk reduction in the primary end-point of progression to overt proteinuria, compared with a control group (placebo in addition to other non-excluded antihypertensive therapies), p = 0.0004.1
In IDNT, the primary end-point was the time until the first occurrence of doubling of serum creatinine, or end-stage renal disease, or all-cause mortality. The irbesartan group demonstrated:
- a 20% relative risk reduction in the primary end-point compared with the control group (placebo in addition to other non-excluded and antihypertensive therapies), p = 0.02
- a 23% relative risk reduction versus the amlodipine group, p = 0.006.2
In a recently updated position statement by the American Diabetes Association on diabetic nephropathy,3 the recommendation is that in treatment of albuminuria/nephropathy both ACE inhibitors and the AT1 receptor antagonists can be used. The recommendations are as follows:
- in hypertensive and non-hypertensive type 1 diabetic patients with microalbuminuria or clinical albuminuria, ACE inhibitors are the initial treatment of choice
- in hypertensive type 2 diabetic patients with microalbuminuria or clinical albuminuria, AT1 receptor antagonists are the initial drugs of choice.
While the AT1 receptor antagonists are a newer class of drug, and data in the past have been limited, there is certainly a growing body of evidence such as PRIME on their use in hypertensive diabetic patients.
- Parving HH, Lehnert H, Brochner-Mortensen J, Gomis R, Andersen S, Arner P. The effect of irbesartan on the development of diabetic nephropathy in patients with type 2 diabetes. N Engl J Med 2001;345:870-8.
- Lewis EJ, Hunsicker LG, Clarke WR, Berl T, Pohl MA, Lewis JB, et al. Renoprotective effect of the angiotensin-receptor antagonist irbesartan in patients with nephropathy due to type 2 diabetes. N Engl J Med 2001;345:851-60.
- American Diabetes Association. Diabetic nephropathy: position statement. Diabetes Care 2002;25(Suppl 1):S85-S89.
- Brenner BM, Cooper ME, de Zeeuw D, Keane WF, Mitch WE, Parving HH, et al. Effects of losartan on renal and cardiovascular outcomes in patients with type 2 diabetes and nephropathy. N Engl J Med 2001;345:861-9.