Youth With Type 2 Diabetes Have Higher Risk Of Retinopathy Compared To T1D

A recent study set out to assess the risk-profile of developing diabetes-associated ocular complications (DOAC) among a population-based cohort of children diagnosed with either type 1 diabetes (T1D) or type 2 diabetes (T2D) throughout a 50-year period.

Led by Brian G. Mohney, MD, Department of Ophthalmology, Mayo Clinic, investigators found diabetic retinopathy, proliferative diabetic retinopathy, and the need for pars plana vitrectomy occurred within a shorter diabetes duration for children with T2D in comparison with T1D, with an almost two-time risk of developing retinopathy in children with T2D.

Study Methods

In doing so, Mohney and colleagues collected the medical records of all patients younger than 22 years old who were newly diagnosed with diabetes from January 1970 - December 2019 in Olmsted County, Minnesota.

They noted a diagnosis of T1D was confirmed for inclusion if the medical record reported a diagnosis of insulin-dependent diabetes mellitus or type 1 diabetes with subsequent treatment consistent with management of T1D. On the other hand, a diagnosis of T2D was confirmed as non-insulin-dependent diabetes mellitus or type 2 diabetes.

Any change in retinopathy status was recorded during follow-up eye examination through 40 years of age. The DOACs assessed in the study included nonproliferative diabetic retinopathy (NPDR), proliferative diabetic retinopathy (PDR), diabetic macular edema (DME), a visually significant cataract (VSC), and the need for pars plana vitrectomy (PPV).

Main outcomes were estimated using the Kaplan-Meier Survival method, including an additional calculation of hazard ratios (HR) and 95% CI for comparison.

What were their findings?

Data show a total of 1362 unique individuals with a diagnostic code of diabetes before 22 years of age, with 606 meeting inclusion criteria. Of that number, 525 (86.6%) underwent ≥1 eye examination after diagnosis of diabetes, excluding 81 (13.4%) without an examination.

Additionally, the children met diagnostic criteria to distinguish between T1D (n = 461, 87.8%) and T2D (n = 64, 12.2%), while they were followed up for a mean of 13.6 years and 8.6 years, respectively. The mean age of children at diagnosis of diabetes was 12.1 years, with a total of 264 male children (50.3%).

In terms of demographic data, White children made up a significantly larger percentage of the T1D cohort, in comparison to the T2D cohort (384, 83.3% versus 35, 54.7%; P < .001), while Asian and Black children (9, 14.1% versus 3, 0.7%; P < .001) and Black (12, 18.7% versus 21, 4.5%; P < .001) made up a larger percentage of the T2D cohort.

Mohney and team observed diabetes-associated ocular complications occurred in 147 of the 461 children (31.2%) with T1D during a mean follow-up of 14 years and in 17 of 64 children (26.6%) with T2D. during a mean follow-up of 9 years.

Data show the HR of the risk between T1D and T2D rates of developing complications were 1.88 (95% CI, 1.13 - 3.12; P = .02) for any diabetic retinopathy (NPDR or greater), 2.33 (95% CI, 0.99 - 5.50, P = .0.48) for PDR, 1.49 (95% CI, 0.46 - 4.89, P = .50) for diabetic macular edema, 2.43 (95% CI, 0.54 - 11.07; P = .24) for a visually significant cataract, and 4.06 (95% CI, 1.34-12.33; P = .007) for requiring pars plana vitrectomy by 15 years after the diagnosis of diabetes.

Adjustments for race using self-identification of White or not White, the adjusted HR of developing any type of retinopathy was 1.63 (95% CI, 0.96 - 2.79, P = .07) and the adjusted HR of developing PDR was 2.02 (95% CI, 0.79 - 5.16, P = .14).

By 15 years of diabetes duration, data show the relative risk of developing retinopathy in patients with T2D versus T1D was 1.88 (95% CI, 1.33 - 3.12, P = .02).

What were the takeaways?

Overall, investigators noted the cohort’s data show patients with T2D developed vision-threatening retinopathy from a shorter diabetes duration, as well as at a higher rate compared to children with T1D.

“This suggests that the natural history of retinopathy development among youth diagnosed with T2D may differ from that in youth diagnosed with T1D, where patients with T2D may be more susceptible to developing retinopathy than those with T1D despite controlling for diabetes disease duration,” investigators wrote.

The study, “Ocular Sequelae in a Population-Based Cohort of Youth Diagnosed With Diabetes During a 50-Year Period,” was published in JAMA Ophthalmology.