Objective: To study the effect of lisinopril on the exercise-induced urinary albumin excretion rate.
Research design and methods: A total of 26 IDDM patients with normoalbuminuria were randomized into two groups, with one group receiving placebo (n = 13, age 36 +/- 3 years, BMI 24.5 +/- 1.1 kg/m2) and the other group receiving an average of 15 mg lisinopril daily (n = 13, age 34 +/- 2 years, BMI 24.4 +/- 0.9 kg/m2). Overnight and exercise-induced urinary albumin excretion rate was measured at baseline and after 1 and 2 years of treatment. Two patients in the placebo group and none in the lisinopril group developed microalbuminuria.
Results: In the lisinopril group, the exercise-induced urinary albumin excretion rate diminished 46% after the 1st year (P = 0.059) and 66% (P < 0.01) after the 2nd year. However, it remained unchanged in the control group. Systolic blood pressure (sBP) and diastolic blood pressure (dBP) were similar at baseline and after 1 year, but at 2 years, sBP was 13 mmHg lower (P = 0.03) and dBP was 9 mmHg lower (P = 0.052) in the lisinopril group as compared with the control group. The dBP decreased significantly at 1 and 2 years in the lisinopril group, while there was no significant change in the sBP. In the whole group at baseline, the overnight albumin excretion rate correlated with HbA1c (r = 0.50, P < 0.01) and the duration of diabetes (r = 0.39, P < 0.05), and sBP correlated with both the overnight (r = 0.42, P < 0.05) and the exercise-induced (r = 0.48, P < 0.05) albumin excretion rate.
Conclusions: Glycemic control and blood pressure are directly related to the overnight albumin excretion rate also in normotensive normoalbuminuric IDDM patients. Lisinopril treatment reduces the exercise-induced urinary albumin excretion rate in such patients. These data suggest a protective effect of lisinopril against the development of microalbuminuria.