Persistent microalbuminuria after treatment with renin-angiotensin axis blockers: causes and results of treatment intensification

Abstract

Aims: The first phase of this study aimed to determine the causes of persistent microalbuminuria after treatment with renin—angiotensin axis (RAA) blocking drugs. In a second phase we tried to determine if strict control of blood pressure and intensive RAA blockade could induce remission or reduction of microalbuminuria in clinical (primary care) practice. Patients and methods: The study included both diabetic patients and non-diabetic hypertensive patients treated with RAA drugs in the presence of microalbuminuria. 211 patients were recruited (mean age 66.6±11.3 years, 111 men, 117 were diabetic). In the first phase treatment was optimized at standard doses. In the second phase treatment was increased during a three months period to reach a blood pressure (BP) < 130/80 mmHg by adding other antihypertensive treatment and to obtain maximal RAA blockade using long-acting drugs, increased dosage, or adding further medication at night. Results: Initial mean BP was 141±16/81±11 mmHg. BP control was unsatisfactory (control of systolic blood pressure [SBP] 19.3%; diastolic blood pressure [DBP] 37.6%). Dosage of RAA blocking drugs was inadequate in 21% of patients. Only 27.4% of patients were taking antihypertensive drugs at night. 30.1% of patients took once daily short acting drugs. During the studymean SBP was reduced to 137±13 mmHg (p < .001) and DBP decreased to 79±10 mmHg (p < .001). Control of SBP improved to 24.5% and DBP control went to 44.4%. Mean microalbuminuria decreased from 64.4±47.0 mg/day to 50.1±53.0 mg/day (p < .001) and the prevalence of microalbuminuria was reduced to 59.1%. Conclusions: Persistent microalbuminuria was associated with poor blood pressure control and inadequate drug dosage. Low frequency of administration of drugs at night and inappropriate once-daily pills intake were frequent. Strict control of blood pressure and intensive RAA blockade significantly reduced the prevalence of microalbuminuria.