Issue 142 Item 11 Risk of Retinopathy Is Lower in Type 2 With Onset in Youth

“The epidemic of type 2 diabetes in youth is likely to lead to an epidemic of microvascular disease while these patients are still young adults.” In a recent study it was shown that, the risk of retinopathy in relation to disease duration is lower in those who developed diabetes at a young age than in those with onset in adulthood.. JohnstonSue@uams.edu

Dr. Jonathan Krakoff and colleagues from the National Institutes of Health, Phoenix, Arizona, followed patients diagnosed with diabetes for microvascular complications in a longitudinal study of health in the Pima Indians of Arizona. They compared the risk of retinopathy and nephropathy in patients with youth-onset type 2 diabetes (before 20 years of age) with that in patients with adult-onset diabetes.

"Diabetes was diagnosed in 178 subjects before 20 years of age (youth), in 1359 subjects at 20 to 39 years of age (younger adults) and in 971 subjects at 40 to 59 years of age (older adults)," the authors note. They calculated incidence rates of retinopathy and nephropathy by age at diagnosis.

Thirty-five patients with youth-onset diabetes developed nephropathy over 25 years. This incidence rate was similar to that of patients with adult-onset diabetes (p = 0.77). However, those with youth-onset diabetes had significantly lower incidence rates of retinopathy (p = 0.007).

Specifically, compared with subjects in the adult-onset group, those in the youth-onset group had a lower risk of retinopathy after adjusting for fasting glucose level, sex, mean arterial pressure, and duration to first examination after diabetes diagnosis (hazard rate ratio [HRR] 0.42, p = 0.003). The risk of nephropathy was similar between the groups (HRR 1.2, p = 0.38).

Dr. Krakoff and colleagues point out that, although the risk of retinopathy in youth is relatively low, nonetheless a "substantial" proportion of such patients do develop retinopathy at a young age. Given that, along with the undiminished risk of nephropathy, they conclude that "the epidemic of type 2 diabetes in youth is likely to lead to an epidemic of microvascular disease while these patients are still young adults." Diabetes Care 2003;26:76-81.