A new research letter identified key risk factors for the development and progression of diabetic retinopathy in young adults with type 1 diabetes. Using data from the Swedish National Diabetes Register, the study featured in the letter evaluated the impact of risk factors beyond glucose control on diabetic retinopathy development and progression over an extended follow-up period from January 1998 to December 2017.

The cohort in this registry-based study included 9,358 individuals with type 1 diabetes (T1D) who were tracked for an average of 11 years. Mean baseline hemoglobin A1c (HbA1c) was 7.9% (63 mmol/mol). Both sexes were included—44% female—and participants were a mean age of 14 years at baseline. Incidence of diabetic retinopathy (DR), ranging from simplex DR to proliferative retinopathy, was assessed at intervals spanning 8 to 20 years after T1D diagnosis.

HbA1c was the strongest predictor of DR. For any DR, the odds ratio (OR) was 1.81 per 1-SD increase in HbA1c. OR was 2.66 for proliferative DR or need for laser photocoagulation.

Higher body mass index increased DR risk (OR = 1.30 for any DR), as did increased systolic and diastolic blood pressure (SBP, DBP). OR for SBP was 1.24 for any DR and was 1.35 for proliferative DR in DBP. Smokers had a 20% increased risk of any DR (OR = 1.20), while higher high-density lipoprotein (HDL) cholesterol was protective (OR = 0.87).

Hyperglycemia was the dominant factor for severe DR, while obesity and hypertension were less predictive.

In their JAMA Ophthalmology article, the researchers concluded: “This study confirms hyperglycemia as the dominant risk factor for retinopathy but also highlights that overweight, obesity, and hypertension need to be managed not only for cardiovascular diseases but also to potentially reduce the risk of retinopathy.”

A full list of author disclosures can be found in the published research