Fasting plasma glucose variability is an independent risk factor for diabetic retinopathy and diabetic macular oedema in type 2 diabetes: An 8-year prospective cohort study

Importance Long-term stability in plasma glucose may affect the development of diabetic retinopathy (DR) and diabetic macular oedema (DMO). Background To investigate the associations between glycaemic variability and the development of DR and DMO in type 2 diabetes (T2D). Design An 8-year prospective cohort study. Participants 2005 patients with T2D. Methods DR and DMO were detected with non-mydriatic fundus photography. Main outcome measures The visit-to-visit variability of fasting glucose or HbA1c was calculated as the standard deviation (SD) or coefficient of variation (CV = SD/mean) of all records during the follow-up periods or before the onset of the targeted event. Cox regression analysis was used to evaluate the hazard ratios (HRs) for new-onset DR, proliferative diabetic retinopathy (PDR), and DMO. Results After adjusting for the baseline and mean follow-up values, the SD and CV of fasting glucose during the follow-up periods were both correlated with the development of PDR (SD: HR = 1.011, P = .005; CV: HR = 6.858, P < .001), and DMO (SD: HR = 1.008, P = .038; CV: HR = 4.027, P = .017). As for HbA1c, neither the SD nor CV was correlated with the development of DR, PDR, or DMO (P > .05 for all). Conclusions and relevance High visit-to-visit fasting glucose variability was associated with new-onset PDR and DMO, independent of baseline and mean follow-up fasting glucose and HbA1c in T2D. Long-term stability in plasma glucose is important for reducing the risk of the development and progression for DR and DMO.