Regression of microalbuminuria in type 2 diabetics after switch to irbesartan treatment : an observational study in 38 016 patients in primary care.

OBJECTIVE

This study aimed to assess the blood pressure-lowering potency, renoprotective efficacy and safety of the angiotensin II type 1 (AT(1))-receptor blocker irbesartan in monotherapy or in combination with hydrochlorothiazide or other antihypertensive medications in patients with type 2 diabetes mellitus switched from various antihypertensive pretreatments.

DESIGN AND METHODS

Multicentre, open, prospective, 6-month observational study in 38 016 patients at 9838 general practitioners' offices throughout Germany. Microalbuminuria in type 2 diabetics was measured with semiquantitative immunological Micral-II urine dipstick tests.

MAIN OUTCOME MEASURE

Proportion of patients with albuminuria at baseline and at 3 and 6 months. Analysis of adverse events.

RESULTS

The study population consisted of an equal number of males and females, mean body mass index was 28.4 kg/m(2), and mean glycosylated haemoglobin (HbA(1c)) was 7.2%. After the switch to irbesartan (in 86% of patients to the 300mg dosage in mono- or combination therapy), mean systolic/diastolic blood pressure was decreased by 23/12mm Hg. Irbesartan treatment over 6 months reduced the proportion of patients with microalbuminuria from 49.2 to 23.2% (relative reduction: 52.8%; p < 0.05) and the rate of patients with macroalbuminuria from 6.0 to 4.4% (relative reduction: 26.7%; p < 0.05). The renoprotective effect of irbesartan was consistent in various subgroups (analyses by sex, weight, diabetes duration, insulin treatment, strength of blood pressure-lowering effect, and antihypertensive pretreatment). Tolerability was excellent: 99.6% of patients remained free of any adverse events during the study.

CONCLUSION

The profound blood pressure-lowering and renoprotective effect of irbesartan in type 2 diabetes documented in clinical endpoint studies was confirmed in second-line therapy in a large sample of primary-care patients. Furthermore, in patients switched from previous ACE-inhibitor therapy, the renoprotective effect of irbesartan was of the same magnitude as in the total cohort.