NEW YORK (Reuters Health) – The onset of type 2 diabetes before middle age is independently associated with a higher prevalence and greater severity of diabetic retinopathy, investigators in Australia have found.
“This further supports the importance of delaying development of diabetes and also implies a need for more stringent metabolic targets for younger individuals,” Dr. Jencia Wong and colleagues write in the October issue of Diabetes Care.
To determine correlates of risk for diabetic retinopathy, the research team at the University of Sydney studied two groups of patients: 624 patients with type 2 diabetes duration of 20-30 years, and group 852 patients with type 2 diabetes duration of 10-12 years. Patients were also stratified according to age of onset and glycemic control.
Multivariate regression analysis showed that age of onset is a risk factor for the development of retinopathy, independent of disease duration, glycemic control, and other risk factors. Compared with patients who developed diabetes after age 55, the risk of retinopathy was nearly doubled among patients diagnosed before age 45.
The greatest impact was observed among patients with a diabetes diagnosis before 45 years of age and a mean A1C > 9% — who had an odds ratio of retinopathy of 16.6 — compared with patients with a diabetes diagnosis after age 55 and a mean A1C < 7%.
“This suggests an increased inherent tissue susceptibility to the damaging effects of hyperglycemia at a younger age,” Dr. Wong and her associates conclude.
Diabetes Care 2008;31:1985-1990.