title: Non-linear effects of blood pressure and glycosylated haemoglobin on progression of diabetic nephropathy.
abstract: OBJECTIVE
  To describe the long-term simultaneous impacts of blood pressure and glycosylated haemoglobin values on the risk of progression of diabetic nephropathy.
  
  
  METHODS
  Prospective, multicentre, 6-year follow-up study.
  
  
  METHODS
  One reference centre (university department of internal medicine) and nine general hospitals.
  
  
  METHODS
  A total of 601 type 1 diabetic patients on intensive insulin therapy with and without diabetic nephropathy.
  
  
  METHODS
  Progression of nephropathy was defined as change for the worse within five stages of nephropathy by at least one of these stages during the study period. By the use of logistic regression, the relationship between metabolic and blood pressure control and the risk of nephropathy progression was quantified.
  
  
  RESULTS
  The main determinants of nephropathy progression were glycosylated haemoglobin and blood pressure, which were both non-linearly associated with the risk of progression. No significant threshold levels for any of the predictors of progression were identified.
  
  
  CONCLUSIONS
  The results of this study underline the importance of optimizing metabolic and blood pressure control to arrest the progression of diabetic nephropathy without the evidence for a clinically relevant threshold effect.
authors.affiliation: Department of Metabolic Diseases, Heinrich-Heine-University of Düsseldorf, Germany. Sawicki@med.uni-duesseldorf.de
authors.forename: P T
authors.initials: PT
authors.lastname: Sawicki
authors.forename: R
authors.initials: R
authors.lastname: Bender
authors.forename: M
authors.initials: M
authors.lastname: Berger
authors.forename: I
authors.initials: I
authors.lastname: Mühlhauser
mesh_terms: D000328:Adult; D001794:Blood Pressure; D003928:Diabetic Nephropathies / Q000097:blood / Q000503:physiopathology*; D003971:Diastole; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006442:Glycated Hemoglobin / Q000378:metabolism*; D006801:Humans; D016015:Logistic Models; D008297:Male; D011446:Prospective Studies; D012306:Risk; D013599:Systole
chemical_list: D006442:Glycated Hemoglobin