title: Novel versus traditional risk markers for diabetic retinopathy.
abstract: OBJECTIVE
  To explore the relative contribution of novel and traditional risk markers for diabetic retinopathy (DR).
  
  
  METHODS
  A clinic-based study of 224 diabetic patients (85 type 1, 139 type 2) from a diabetes clinic was performed. DR was graded from fundus photographs according to the Airlie House Classification system and classified as absent or present (at least ETDRS level 14). Novel risk markers assessed included serum apolipoprotein (Apo) AI and B, skin microvascular responses to acetylcholine (endothelium-dependent) and sodium nitroprusside (endothelium-independent) iontophoresis, flicker-light-induced retinal vasodilation and retinal vascular tortuosity. Relative contribution was determined by semi-partial correlation coefficient generated from a logistic regression model containing all traditional and novel risk markers simultaneously.
  
  
  RESULTS
  There were 144 (64.3%) participants with DR. Of the novel markers, ApoAI, flicker-light-induced vasodilation and retinal arteriolar tortuosity were significantly associated with DR, independently of traditional measures (all p < 0.03). Diabetes duration contributed most (51%) to the risk of DR, followed by ApoAI (16%), systolic blood pressure (13%), retinal arteriolar tortuosity (8%) and flicker-light-induced venular and arteriolar dilation (3% and 0.5%, respectively).
  
  
  CONCLUSIONS
  ApoAI and retinal arteriolar tortuosity made considerable contributions to DR risk, independently of traditional risk markers. Findings from this study suggest that serum ApoAI and retinal arteriolar tortuosity may be novel and independent risk markers of DR.
authors.affiliation: Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, University of Melbourne, 32 Gisborne Street, Melbourne, VIC 3002, Australia.
authors.forename: M B
authors.initials: MB
authors.lastname: Sasongko
authors.forename: T Y
authors.initials: TY
authors.lastname: Wong
authors.forename: T T
authors.initials: TT
authors.lastname: Nguyen
authors.forename: J E
authors.initials: JE
authors.lastname: Shaw
authors.forename: A J
authors.initials: AJ
authors.lastname: Jenkins
authors.forename: J J
authors.initials: JJ
authors.lastname: Wang
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016632:Apolipoprotein A-I / Q000097:blood*; D001160:Arterioles / Q000473:pathology* / Q000528:radiation effects; D015415:Biomarkers / Q000097:blood; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D003930:Diabetic Retinopathy / Q000097:blood* / Q000175:diagnosis / Q000473:pathology* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008027:Light; D008297:Male; D008875:Middle Aged; D012171:Retinal Vessels / Q000473:pathology* / Q000528:radiation effects; D012307:Risk Factors; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D014664:Vasodilation / Q000528:radiation effects; D055815:Young Adult
chemical_list: C505693:APOA1 protein, human; D016632:Apolipoprotein A-I; D015415:Biomarkers