Discordance in risk factors for the progression of diabetic retinopathy and diabetic nephropathy in patients with type 2 diabetes mellitus

Aims/Introduction: We aimed to investigate whether there are differences in the risk factors or markers for the progression of diabetic retinopathy (DR) and diabetic nephropathy (DN) in type 2 diabetes mellitus. Materials and Methods: We carried out a 3-year retrospective cohort study of 604 patients with type 2 diabetes mellitus. The outcomes were the progression of DR (worsening of the DR stage) and DN (an estimated glomerular filtration rate decline >12%) at the 3-year follow up. The mean hemoglobin A1c (HbA1c) level and HbA1c variability (HbA1c-VAR) were calculated. Results: The mean HbA1c and HbA1c-VAR levels were higher in the DR progressors (n = 67) than in the DR non-progressors (n = 537). The mean HbA1c was a significant predictor for DR progression independent of the duration of diabetes and HbA1c-VAR levels. The urine albumin-to-creatinine ratio at baseline and HbA1c-VAR levels were higher in the DN progressors (n = 34) than in the DN non-progressors (n = 570). The triglyceride to high-density lipoprotein cholesterol ratio at baseline tended to be higher in the DN progressors than in the DN non-progressors. HbA1c-VAR levels and the triglyceride-to-high-density lipoprotein cholesterol ratio were significant predictors for DN progression independent of estimated glomerular filtration rate and the urine albumin-to-creatinine ratio. Conclusions: Average glycemia was significantly associated with progression of DR, whereas glycemic variability and dyslipidemia were significantly associated with progression of DN in type 2 diabetes mellitus.