Long-term glycemic variability has been proposed as a contributor to microvascular complications beyond average glycemic exposure alone. A study published in Acta Diabetologica evaluated the relationship between long-term HbA1c variability and diabetic retinopathy (DR) in adults with diabetes participating in a systematic eye screening program.

The study screened 379 adults with type 1 and type 2 diabetes. Long-term glycemic variability was estimated using the coefficient of variation (CV) of serial HbA1c measurements. DR was evaluated using dilated fundus photography, and multivariable logistic regression analyses were performed to assess associations between HbA1c variability and DR after adjustment for potential confounding factors.

Findings

• DR prevalence was 12.4%, with most cases classified as mild non-proliferative DR.
• The median HbA1c coefficient of variation was 7.0%.
• In unadjusted analyses, mild DR incidence was higher in the low glycemic variability group than in the high variability group.
• After multivariable adjustment, higher HbA1c coefficient of variation demonstrated an independent relationship with DR presence (β = 0.643; P = 0.042).
• Diabetes duration and age also remained independently associated with DR (both P < 0.001).

The findings demonstrated that long-term glycemic variability estimated by HbA1c coefficient of variation was independently associated with DR in adults with diabetes. These results support further evaluation of glycemic variability as a potential contributor to microvascular risk beyond mean glycemic control.