title: Benefits of Renin-Angiotensin blockade on retinopathy in type 1 diabetes vary with glycemic control.
abstract: OBJECTIVE
  Optimal glycemic control slows diabetic retinopathy (DR) development and progression and is the standard of care for type 1 diabetes. However, these glycemic goals are difficult to achieve and sustain in clinical practice. The Renin Angiotensin System Study (RASS) showed that renin-angiotensin system (RAS) blockade can slow DR progression. In the current study, we evaluate whether glycemic control influenced the benefit of RAS blockade on DR progression in type 1 diabetic patients.
  
  
  METHODS
  We used RASS data to analyze the relationships between two-steps or more DR progression and baseline glycemic levels in 223 normotensive, normoalbuminuric type 1 diabetic patients randomized to receive 5 years of enalapril or losartan compared with placebo.
  
  
  RESULTS
  A total of 147 of 223 patients (65.9%) had DR at baseline (47 of 74 patients [63.5%] in placebo and 100 of 149 patients [67.1%] in the combined treatment groups [P = 0.67]). Patients with two-steps or more DR progression had higher baseline A1C than those without progression (9.4 vs. 8.2%, P < 0.001). There was no beneficial effect of RAS blockade (P = 0.92) in patients with baseline A1C ≤7.5%. In contrast, 30 of 112 (27%) patients on the active treatment arms with A1C >7.5% had two-steps or more DR progression compared with 26 of 56 patients (46%) in the placebo group (P = 0.03).
  
  
  CONCLUSIONS
  RAS blockade reduces DR progression in normotensive, normoalbuminuric type 1 diabetic patients with A1C >7.5%. Whether this therapy could benefit patients with A1C ≤7.5% will require long-term studies of much larger cohorts.
authors.affiliation: Department of Medicine, University of Minnesota, Minneapolis, MN, USA. hari0049@umn.edu
authors.forename: Tasma
authors.initials: T
authors.lastname: Harindhanavudhi
authors.forename: Michael
authors.initials: M
authors.lastname: Mauer
authors.forename: Ronald
authors.initials: R
authors.lastname: Klein
authors.forename: Bernard
authors.initials: B
authors.lastname: Zinman
authors.forename: Alan
authors.initials: A
authors.lastname: Sinaiko
authors.forename: M Luiza
authors.initials: ML
authors.lastname: Caramori
mesh_terms: D000328:Adult; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use; D001786:Blood Glucose / Q000187:drug effects; D003922:Diabetes Mellitus, Type 1 / Q000188:drug therapy* / Q000378:metabolism; D003930:Diabetic Retinopathy / Q000188:drug therapy* / Q000378:metabolism; D004656:Enalapril / Q000627:therapeutic use; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D019808:Losartan / Q000627:therapeutic use; D008297:Male; D012084:Renin-Angiotensin System / Q000187:drug effects*; D055815:Young Adult
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D001786:Blood Glucose; D004656:Enalapril; D006442:Glycated Hemoglobin; D019808:Losartan