Abstract

Objective: To examine the relationship of retinal vascular caliber with diabetes, glycemia and diabetic retinopathy.

Research Design and Methods: Population-based study using data from the Multi-Ethnic Study of Atherosclerosis (MESA), comprising 5,976 persons (whites, blacks, Hispanics and Chinese) residing in six U.S. communities who were free of clinical cardiovascular disease at baseline. Retinal vascular caliber was measured from digital retinal photographs.

Results: There were 4585 persons with normal fasting glucose (NFG), 499 with impaired fasting glucose (IFG), 165 persons with diabetes with retinopathy signs and 727 with diabetes without. After multivariate analysis, retinal arteriolar caliber increased from 143.8 μm in subjects with NFG to 144.5 μm in IFG and 146.1 μm in diabetes (p<0.001 for trend). Retinal venular caliber increased from 214.4 μm in NFG to 216.7 μm in IFG and 218.0 μm in diabetes (p<0.001 for trend). Retinal venular caliber was significantly larger with increasing levels of fasting glucose and hemoglobin A_1C. In a sub-group analysis by ethnicity, the association between wider arteriolar caliber and diabetes was evident in whites only, while wider venular caliber and diabetes was evident in Hispanics and Chinese only. In people with diabetes, eyes with retinopathy had larger retinal venular but not arteriolar caliber.

Conclusions: Retinal arteriolar and venular calibers are larger in persons with diabetes, but the pattern of associations appears to vary by ethnicity. Retinal venular caliber is additionally associated with retinopathy signs. These findings add further to the concept that variations in retinal vascular caliber may reflect early diabetic microvascular damage.