Aims: To assess the course of microalbuminuria in patients with Type 2 diabetes mellitus in general practice and the predictive value of urinary albumin concentration on all-cause mortality, cardiovascular mortality and cardiovascular morbidity.
Methods: Cohort study in Type 2 diabetic patients tested for microalbuminuria in 1992, and re-tested in 1998. During follow-up all cardiovascular morbidity and mortality were recorded.
Results: Of the original sample of 317 patients, 163 patients were re-tested. The mean change in urinary albumin concentration was +16.2 mg/l (range -122.0 to +602 mg/l). Seventy-five per cent of the patients without microalbuminuria in 1992 still had no microalbuminuria in 1998 and 40% of those with microalbuminuria in 1992 reverted to normoalbuminuria in 1998. Cox survival analysis, stratified for age, showed that microalbuminuria at baseline resulted in a risk ratio of all-cause mortality of 1.4 (95% confidence interval 0.8-2.7), of cardiovascular mortality of 1.2 (0.5-2.8) and of new cardiovascular events (including cardiovascular mortality) of 1.4 (0.8-2.3).
Conclusions: In the majority of patients the change of urinary albumin excretion was small, but the range was wide. A weak non-significant relationship between microalbuminuria and all-cause mortality and cardiovascular morbidity was observed.