Prevalence, progression and modifiable risk factors for diabetic retinopathy in youth and young adults with youth-onset type 1 and type 2 diabetes: The SEARCH for Diabetes in Youth Study

Objective: To determine the prevalence, progression and modifiable risk factors associated with development of DR in a population-based cohort of youth-onset diabetes. 

Research Design and Methods: We conducted a multicenter, population-based prospective cohort study (2002 to 2019) of youth and young adults with youth-onset type 1 (n=2519) and type 2 diabetes (n=447). Modifiable factors included baseline and change from baseline to follow-up in BMI z-score, waist/height ratio, systolic and diastolic blood pressure z-score, and A1C. DR included evidence of mild or moderate non-proliferative DR or proliferative retinopathy. Prevalence estimates were standardized to estimate the burden of DR and inverse probability weighting for censoring was applied for estimating risk factors for DR at two points of follow-up. 

Results: DR in youth-onset type 1 and type 2 diabetes is highly prevalent, with 52% of those with type 1 diabetes and 56% of those with type 2 diabetes demonstrating retinal changes at follow-up (12.5 [SD: 2.2] years from diagnosis). Higher baseline A1C, increase in A1C across follow-up, and increase in diastolic and systolic blood pressure were associated with observation of DR at follow-up for both diabetes types. Increase in A1C across follow-up was associated with retinopathy progression. BMI z-score and waist/height ratio were inconsistently associated, with both positive and inverse associations noted. 

Conclusions: Extrapolated to all youth-onset diabetes in the U.S., we estimate 110,051 cases of DR developing within ~12 years post-diagnosis. Tight glucose and blood pressure management may offer opportunity to mitigate development and progression of DR in youth-onset diabetes.