Prevalence of microalbuminuria and its associated cardiovascular risk: German and Swiss results of the recent global i-SEARCH survey

QUESTION UNDER STUDY: The aim of this study was to determine the prevalence of microalbuminuria (MAU) in hypertensive patients attending an office or hospital based cardiologist or internist. An additional aim was to describe associations between MAU and cardiovascular risk factors as well as to investigate the role of pharmacotherapy. METHODS: International, observational, cross-sectional study of 22282 patients with 5605 attendees in Germany and Switzerland at 444 cardiology centers. Inclusion criteria were male and female outpatients, aged > or =18 years with currently treated or newly diagnosed hypertension (> or =140/90 mm Hg at rest on the day of the study visit) and no reasons for false positive dip stick tests. The main outcome measures were the prevalence of MAU, co-morbid cardiovascular risk factors or disease and their association with the presence of MAU, and the role of pharmacotherapy in modulating prevalence of MAU. RESULTS: Prevalence of MAU in Germany and Switzerland (53.1%) was high, but lower when compared to the prevalence in "other countries" (OC, 60.2%). Routine MAU measurement was performed in 52.9% of the practices only (32.9% OC), although physicians regarded MAU to be important for risk assessment and therapeutic decisions. MAU is highly correlated with a wide variety of cardiovascular risk factors and co-morbid cardiovascular conditions including high waist circumference (55.1% [95%CI 56.0; 59.7]), diabetes (59.1% [56.8; 61.3]), atrial fibrillation (62.3% [57.4; 66.9]) and peripheral arterial disease (67.1% [61.6; 72.2]). Angiotensin receptor blockers (ARBs) appeared to be associated with the lowest risk of MAU (52.1%). Calcium channel blockers (CCBs) were used more frequent in patients with MAU (28.7%) than without (23.4%). CONCLUSIONS: Patients with MAU are common in clinical cardiology and its presence is associated with a wide variety of cardiovascular risk factors and co-morbid cardiovascular conditions. A more aggressive multi-factorial treatment might help to reduce this risk constellation