Articles about Eye Health and Disease 2002
 

Retinal Artery Narrowing Associated with Increased Risk of Developing of Diabetes Mellitus

(From Tien Yen Wong MD and the Atherosclerosis Risk in Communities Study, et al., JAMA 2002;287:2528-2533.)

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. The retinal arteries and veins of the eye are clearly visible for evaluation, and represent one of the few examples where living blood vessels can be directly examined in the body.  This study examined the relationship of retinal arteriolar narrowing, a marker of microvascular damage from aging, hypertension, and inflammation, to the development of diabetes in healthy middle-aged persons.

The results of the study stem from the The Atherosclerosis Risk in Communities Study.  This is an ongoing population-based, prospective 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). The study evaluated the relationship between the development of diabetes (defined as fasting glucose levels of 126 mg/dl, diabetic medications use, or physician diagnosis of diabetes at the fourth examination) to the appearance of the retinal arteries and veins in the retinal photographs.  The retinal arteriole-to-venule ratio (AVR) is a commonly used relationship that allows a comparison between the diameter of retinal arterioles compared to retinal veins, and can be measured in photographs.  Cases of a low AVR indicate that the retinal artery is becoming narrowed in relationship to the vein, which is common in arteriosclerosis.

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 a lower AVR at baseline.  5.2% of persons with the lowest AVR measurements (narrowest arteries) developed diabetes, compared with only 2.4% of those with the best AVR measurements.  This was found to be a statistically significant difference, even after controlling for fasting glucose and insulin levels, family history of diabetes, obesity, physical activity, blood pressure, and other factors.  Persons in the lowest 1/4 of AVR measurements (narrowest arteries) were 71% more likely to develop diabetes than those in the highest 1/4. This association persisted with different diagnostic criteria, such as using a higher fasting blood sugar level as a diagnosis of diabetes, 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 body fat.

The investigators concluded that retinal arteriolar narrowing is independently associated with risk of diabetes, supporting a microvascular role in the development of clinical diabetes.

 

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