Retrospective exploratory analyses on gender differences in determinants for incidence and progression of diabetic retinopathy in Japanese patients with type 2 diabetes mellitus.

Gender differences in risks for macrovascular complications in type 2 diabetes mellitus (T2DM) have been well established. However, the impact of gender differences on diabetic retinopathy (DR) has not been fully elucidated. We therefore retrospectively explored gender-specific determinants for DR in patients with T2DM in a small sized Japanese cohort in Okinawa. There were 214 patients who were diagnosed as no DR (n = 142) and non-proliferative DR (n = 72) in 2009. During the follow-up of median 7 years, 41/142 of incidence, 26/72 of progression, and 67/214 of incidence and progression were observed, respectively. DR was assessed using the modified international clinical DR severity scales. The risks for incidence, progression as well as incidence and progression of DR were comparable between men and women, respectively. Cox proportional hazard models in multivariate analyses demonstrated that the only common determinant in both men and women for DR was the duration of T2DM. Regarding gender-specific determinants, lower level of serum albumin in men as well as higher HbA1c, lower level of estimated glomerular filtration rate, and lower level of serum uric acid in women were extracted, respectively. Although precise mechanisms for such gender-specific determinants of DR still remain unsolved, the present study would highlight a couple of factors associated with gender-specific determinants for DR in a limited numbers of Japanese cohort. Prospective observational studies on gender-specific determinants of DR in a large scale cohort are warranted to further clarify underlying mechanisms.