title: Retinal arteriolar narrowing and risk of diabetes mellitus in middle-aged persons.
abstract: BACKGROUND
  Microvascular processes have been hypothesized to play a role in the pathogenesis of type 2 diabetes mellitus, but prospective clinical data regarding this hypothesis are unavailable.
  
  
  OBJECTIVE
  To examine the relation of retinal arteriolar narrowing, a marker of microvascular damage from aging, hypertension, and inflammation, to incident diabetes in healthy middle-aged persons.
  
  
  METHODS
  The Atherosclerosis Risk in Communities Study, an ongoing population-based, prospective cohort study in 4 US communities that began in 1987-1989. Included in this analysis were 7993 persons aged 49 to 73 years without diabetes, of whom retinal photographs were taken during the third examination (1993-1995).
  
  
  METHODS
  Incident diabetes (defined as fasting glucose levels of > or =126 mg/dL [7.0 mmol/L], casual levels of > or =200 mg/dL [11.1 mmol/L], diabetic medications use, or physician diagnosis of diabetes at the fourth examination) by quartile of retinal arteriole-to-venule ratio (AVR).
  
  
  RESULTS
  After a median follow-up of 3.5 years, 291 persons (3.6%) had incident diabetes. The incidence of diabetes was higher in persons with lower AVR at baseline (2.4%, 3.1%, 4.0%, and 5.2%, from highest to lowest AVR quartile; P for trend < .001). After controlling for fasting glucose and insulin levels, family history of diabetes, adiposity, physical activity, blood pressure, and other factors, persons in the lowest quartile of AVR were 71% more likely to develop diabetes than those in the highest quartile (odds ratio [OR], 1.71; 95% confidence interval [CI], 1.13-2.57; P for trend =.002). This association persisted with different diagnostic criteria (OR, 1.92; 95% CI, 1.10-3.36; P for trend =.01, using a fasting glucose level of > or =141 mg/dL [7.8 mmol/L] as a cutoff), and was seen even in people at lower risk of diabetes, including those without a family history of diabetes, without impaired fasting glucose, and with lower measures of adiposity.
  
  
  CONCLUSIONS
  Retinal arteriolar narrowing is independently associated with risk of diabetes, supporting a microvascular role in the development of clinical diabetes.
authors.affiliation: Department of Ophthalmology, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260. ophwty@nus.edu.sg
authors.forename: Tien Yin
authors.initials: TY
authors.lastname: Wong
authors.forename: Ronald
authors.initials: R
authors.lastname: Klein
authors.forename: A Richey
authors.initials: AR
authors.lastname: Sharrett
authors.forename: Maria I
authors.initials: MI
authors.lastname: Schmidt
authors.forename: James S
authors.initials: JS
authors.lastname: Pankow
authors.forename: David J
authors.initials: DJ
authors.lastname: Couper
authors.forename: Barbara E K
authors.initials: BE
authors.lastname: Klein
authors.forename: Larry D
authors.initials: LD
authors.lastname: Hubbard
authors.forename: Bruce B
authors.initials: BB
authors.lastname: Duncan
mesh_terms: D000368:Aged; D000375:Aging / Q000502:physiology; D003920:Diabetes Mellitus / Q000453:epidemiology* / Q000209:etiology*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000503:physiopathology; D007249:Inflammation; D016015:Logistic Models; D008297:Male; D008833:Microcirculation / Q000502:physiology; D008875:Middle Aged; D010781:Photography; D011446:Prospective Studies; D015356:Retinal Artery Occlusion / Q000209:etiology / Q000503:physiopathology*; D012171:Retinal Vessels / Q000502:physiology; D012307:Risk Factors