Microvascular Disease Linked to Type 2 Diabetes Risk

Microvascular disease may predict subsequent development of type 2 diabetes mellitus 

Even in patients thought to be at low risk, according to results of a study published in the May 15 issue of The Journal of the American Medical Association. Narrowing of the retinal arterioles was independently associated with diabetic risk even in patients without a family history of diabetes or other documented risk factors.  

"Microvascular disease has been hypothesized to contribute to the development of diabetes," write Tien Y. Wong, MD, MPH, from the University of Wisconsin, Madison, and colleagues. "The retinal arterioles offer an excellent opportunity to explore, noninvasively, the prognostic importance of microvascular disease."

Using data from the Atherosclerosis Risk in Communities Study, an ongoing population-based, prospective cohort study, the investigators identified 7993 persons without diabetes, aged 49 to 73 years, who had retinal photographs taken during their third examination.

After a median follow-up of 3.5 years, 291 persons (3.6%) developed diabetes. The incidence of diabetes increased with lower retinal arteriole-to-venule ratio (AVR), and was 2.4% in the highest AVR quartile, 3.1% in the second quartile, 4.0% in the third quartile, and 5.2% in the lowest quartile (P<.001). After controlling for other risk factors, persons in the lowest AVR quartile were 71% more likely to develop diabetes than those in the highest quartile.

Changing the diagnostic criteria for diabetes (from a fasting blood sugar of 126 mg/dL to 141 mg/dL) did not weaken the association, which extended to people without family history of diabetes mellitus, impaired fasting glucose, or adiposity.

While acknowledging other potential weaknesses of this study, the authors note that "we have only shown a short-term association between AVR and incident diabetes; further study is required to determine whether longer-term associations exist."

JAMA. 2002; 287(19):2528-2533