Determination of albuminuria in the urine of diabetics for prevention and control of diabetic nephropathy

THE ISSUE: Diabetes has become the main cause of endstage renal disease. The costs for the treatment of diabetic patients with endstage renal disease have increased in the last years and have become a relevant economic topic of the health service. The first unspecific predictor of a diabetic nephropathy is an albuminuria. The screening for diabetic nephropathy uses microalbuminuria as a proof. OBJECTIVES: What significance does the determination of albuminuria have on the precaution and course-control of the diabetic nephropathy? a) in type 1 diabetic patients. b) in type 2 diabetic patients. Which is an appropriate time to determine the albuminuria for the purpose of precaution and course-control of the diabetic nephropathy? a) in type 1 diabetic patients. b) in type 2 diabetic patients. Which method of testing is most effective concerning economic and medical aspects? METHODS: Published literature from 1998 up to 2004 was identified by searching in the most important databases. Most of the guidelines were found by hand searching in the internet. RESULTS: Of 2,792 citation titles and abstracts examined, 274 articles were retrieved for full-text review. Five metaanalyses and reviews, one review about clearing of guidelines (regarding 18 international guidelines) and four guidelines met the inclusion criteria for screening for microalbuminuria and type 1 diabetes. Seven metaanalyses, one HTA report, one review about clearing of guidelines (regarding 17 international guidelines), and seven guidelines met the inclusion criteria for screening for microalbuminuria and type 2 diabetes. At the moment, the determination of albuminuria still has a great significance because it is recommended in most published literature and guidelines. The time to determine the albuminuria depends on the age of the patients and their type of diabetes. Type 2 diabetic patients should start the determination when the diabetes is diagnosed whereas the determination is recommended five years later when type 1 diabetic patients are concerned. Most guidelines recommend a screening for microalbuminuria every year. DISCUSSION AND CONCLUSION: All guidelines and most of the literature recommend this screening. However, these recommendations are only based on expert consensus. The specificity of this screening is rather low. False positive tests in type 2 diabetic patients will cause psychological problems. A positive test leads to the recommendation to achieve "normal blood pressure" and "normoglycaemia" - but this applies to each diabetic patient. Based on these facts, the screening for albuminuria in type 1 or type 2 diabetes patients cannot be recommended as long as benefit has not been demonstrated by large, clinical, controlled trials. Without an evidence of the benefit, this screening cannot be economic.