Retinal Vessel Diameters and Risk of Impaired Fasting Glucose or Diabetes

The association between a smaller retinal arteriolar-to-venular ratio (AVR) and incident diabetes may be due to arteriolar narrowing, venular dilatation, or both. We investigated associations between baseline vessel diameters and incident impaired fasting glucose or diabetes in a population-based cohort (aged 55 years). Baseline retinal vessel diameters (1990-1993) were measured on digitized images of 2,309 subjects with a normal glucose tolerance test (postload glucose \<7.8 mmol/l). At follow-up (1997-1999), impaired fasting glucose was defined as 6.1-7.0 mmol/l and diabetes as 7.0 mmol/l and/or antidiabetic medication use. Odds ratios (ORs) per SD increase in venular diameters were 1.13 (95% CI 1.00-1.29) for impaired fasting glucose and 1.09 (0.90-1.33) for diabetes. ORs per SD decrease in arteriolar diameters were 1.12 (0.98-1.27) and 1.08 (0.89-1.31) and per SD decrease in AVR were 1.29 (1.13-1.46) and 1.19 (0.98-1.45). After adjustment for cardiovascular risk factors, the associations were unaltered for venules and disappeared for arterioles. After stratification on age, associations between venular dilatation and impaired fasting glucose (1.23 [1.02-1.47]) or diabetes (1.18 [0.89-1.56]) were mainly present in participants aged \