Abstract
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.
Keywords: prevention and control
Abstract
Einleitung
In den letzten Jahren hat die diabetische Nephropathie an großer Bedeutung gewonnen, da sie mittlerweile die Hauptursache für die terminale Niereninsuffizienz und damit zu einer großen Kostenbelastung des Gesundheitswesens geworden ist.
Die Mikroalbuminurie ist der erste klinische Marker einer diabetischen Nephropathie und damit bei der Diagnostik einer diabetischen Nephropathie von besonderer Bedeutung.
Fragestellung
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Welchen Stellenwert hat die Bestimmung der Albuminausscheidung im Urin bezüglich Vorsorge und Verlaufskontrolle der diabetischen Nephropathie?
a) Bei Typ 1-Diabetikern
b) Bei Typ 2-Diabetikern
-
Wann sollte zur Vorsorge und Verlaufskontrolle der diabetischen Nephropathie eine Bestimmung der Albuminausscheidung im Urin erfolgen?
a) Bei Typ 1-Diabetikern
b) Bei Typ 2-Diabetikern
Welches Verfahren weist ökonomisch und medizinisch die beste Wirksamkeit auf?
Methodik
Die bei der breit angelegten systematischen Literaturrecherche in den wichtigsten Datenbanken (1998 bis 2004) ermittelten Publikationen bildeten neben den Ergebnissen einer Internetrecherche die Informationsgrundlage.
Ergebnisse
Unter den bearbeiteten 2.792 Publikationen befinden sich fünf Metaanalysen und Übersichtsarbeiten, ein Leitlinien-Clearingbericht (bezüglich 18 internationaler Leitlinien) und vier Leitlinien, die den Einschlusskriterien zum Diabetes mellitus Typ 1 entsprechen. Zum Thema Typ 2-Diabetes und Screening auf Mikroalbuminurie wurden ein HTA-Bericht, sieben Metaanalysen, ein Leitlinien-Clearingbericht (bezüglich 17 internationaler Leitlinien) und sieben Leitlinien ermittelt, die die Einschlusskriterien erfüllen.
Derzeit hat die Bestimmung der Albuminausscheidung im Urin einen hohen Stellenwert, da sie in den meisten publizierten Arbeiten und Leitlinien empfohlen wird.
Der Zeitpunkt der Albuminbestimmung ist abhängig vom Alter und Diabetestyp der Patienten. Während bei Typ 2-Diabetikern direkt nach der Diagnosestellung mit dem Screening begonnen werden sollte, wird das Screening bei Typ 1-Diabetikern erst fünf Jahre später empfohlen.
Die meisten Leitlinien raten ein jährliches Screening.
Diskussion und Schlussfolgerung
Bezüglich der Screeninguntersuchungen besteht in der Literatur weitgehend Übereinstimmung darüber, dass ein Screening notwendig und gerechtfertigt sei.
Diese Meinung basiert jedoch nur auf Studien mit einem sehr niedrigen Evidenzgrad, was zu einer kritischen Betrachtung dieser Haltung führen sollte.
Insbesondere die Spezifität des Screenings bei Typ 2-Diabetikern ist sehr gering. Das falsch positive Ergebnis des Screenings könnte bei einigen Patienten zu einer psychischen Belastung führen.
Zurzeit sind die therapeutischen Konsequenzen des Nachweises einer Mikroalbuminurie nur sehr gering, da die einzigen durch hohe Evidenzgrade belegten Therapiemöglichkeiten (optimale Therapie des Blutdrucks und strenge Einstellung der Blutzuckerwerte) bei allen Diabetikern angestrebt werden sollten.
Aus diesem Grund kann die Bestimmung der Albuminausscheidung im Urin bei Diabetikern zur Vorsorge und Kontrolle der diabetischen Nephropathie bis zum Nachweis des Nutzens durch methodisch gute, kontrollierte, klinische Studien nicht empfohlen werden.
Bei derzeit fehlendem Nachweis des Nutzens ist die Durchführung dieses Screenings nicht ökonomisch.
Executive Summary
1. The issue
Diabetes has become the main cause of end-stage renal disease. 30% to 40% of all type 1 and type 2 diabetic patients develop a diabetic nephropathy. The costs for the treatment of diabetic patients with end-stage renal disease have been rising in the last years and have become a relevant economic topic of the health service.
Diabetic nephropathy is diagnosed by clinical aspects. Patients suffering from diabetes mellitus for several years, diabetic retinopathy, and proteinuria are defined as patients with diabetic nephropathy. However, valid data for this definition are missing for type 2 diabetes.
The earliest clinical predictor of nephropathy is the appearance of low abnormal levels of albumin in the urine, known as microalbuminuria. This is the reason for developing tests for microalbuminuria.
2. 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?
3. Methods
Published literature from 1998 up to 2004 was identified by searching in the following databases: PSYCINFO, PSYNDEX, EMBASE, EMBASE Alert, Int. Health Technology Assessment, MEDLINE, MEDLINE ALERT, SCISEARCH, SOCIAL SCISEARCH, GEROLIT, Heclinet, AMED, Biosis Prev AB, Biotechnobase, Elsevier Biobase, Eth-med, Euroethics, SOMED, DARE, NEED, INAHTA, and Cochrane Library. Most of the guidelines were found by hand searching in the internet.
4. Results and discussion
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.
The methodological quality of the articles varied but was on average level. Most of these trials were cross-sectional and cohort studies. Almost each guideline recommends a screening for microalbuminuria every year. Type 1 diabetic patients should start the screening five years after diagnosis of diabetes. Different recommendations exist with regard to the screening for microalbuminuria in young type 1 diabetic patients, especially in puberty.
Microalbuminuric type 1 and type 2 patients should be screened every three to six months.
Most of these recommendations are only based on expert consensus. There are no randomised controlled trials which proof the recommendations.
Sensitivity and specificity of microalbuminuria are high in type 1 diabetes, whereas in type 2 diabetes sensitivity of the microalbuminuria is high but specificity is only moderate. As the test will be incorrectly positive in many type 2 diabetic patients, these patients suffer the threatening of dialysis. In addition, there is no real consequence of a positive test result regarding the therapy of the diabetic nephropathy. The only proofed therapy is to achieve strictly normal values of glycosylated hemoglobin (HbA1c) and a normal blood pressure (<120/80 mm Hg).
5. Conclusion
Most guidelines recommend an albumin screening every year, but these recommendations are only based on expert consensus.
The specificity of this screening is rather low.
False positive tests in type 2 diabetic patients cause psychological problems.
The consequence of a positive test leads to the recommendation to achieve a "normal blood pressure" and a "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.
Without the evidence of the benefit, this screening cannot be economic.
In order to prove a benefit of this screening, large, clinical, controlled trials are necessary.