Beyond HbA1c: Albumin-corrected fructosamine is associated with diabetic retinopathy in well-controlled type 2 diabetes

AIMS: Diabetic retinopathy (DR) can occur in type 2 diabetes (T2DM) despite well-controlled glycaemia (HbA1c <7.0%), indicating that glycation-related factors beyond HbA1c may contribute to its development. Albumin-corrected fructosamine (AlbF) may provide complementary information on glycaemic exposure relevant to DR risk. METHODS: This retrospective cross-sectional study included 1,090 T2DM patients. AlbF was calculated as serum fructosamine/albumin ratio. DR was assessed by standardized ophthalmic examination. Multivariable logistic regression examined the association between AlbF and DR, adjusting for demographic, metabolic, and clinical covariates. Subgroup analyses were performed by HbA1c level. RESULTS: Higher AlbF was independently associated with DR. In fully adjusted models, each 10 μmol/g increase in AlbF was associated with 65% higher odds of DR (OR 1.65; 95% CI 1.40-1.95). The highest versus lowest AlbF tertile showed nearly fivefold higher odds (OR 4.77; 95% CI 2.99-7.60). The association remained significant in patients with HbA1c <7.0%. Adding AlbF modestly improved discrimination (ΔAUC=0.045; P=0.002), but this improvement should be interpreted cautiously. CONCLUSIONS: AlbF is independently associated with DR in T2DM, including well-controlled individuals. These findings suggest AlbF may reflect glycaemic aspects not captured by HbA1c. Given the cross-sectional design, results should be interpreted as associations, not prediction or causality.