The relationship between retinopathy and serum 25-hydroxy vitamin D level in patients with type 2 diabetes mellitus

Objective:To explore the relationship between diabetic retinopathy(DR) and serum 25-hydroxy vitamin D(25-OH-VD) level in patients with type 2 diabetes mellitus(T2DM).Methods:The 162 T2DM patients were divided into the single diabetes mellitus group(DM group,66 cases),non-proliferative diabetic retinopathy(NPDR group,52 cases) and proliferative diabetic retinopathy(PDR group,44 cases) according to the fundus oculi results.The clinical characteristics and biochemical parameters were investigated to analyze the risk factors of DR.Results:The duration and glycated hemoglobin(HbA1C) levels in PDR and NPDR groups were higher than those in DM group(P<0.05 to P<0.01),and the duration and HbA1C level in PDR group were higher than those in NPDR group(P<0.05 to P<0.01).The 25-OH-VD levels in PDR and NPDR groups were significantly less than that in DM group(P<0.01),and the 25-OH-VD level in PDR group was significantly lower than that in NPDR group(P<0.01).The systolic blood pressure(SBP) in PDR group was higher than that in DM group(P<0.05),but the difference of the SBP level between PDR and NPDR group was not statistically significant(P >0.05).Correlation analysis showed that the duration,SBP and HbA1C level of patients were positive correlation with DR(P<0.05 to P<0.01),and the level of serum 25-OH-VD were negative correlation with DR(P<0.01).Multiple logistic regression analysis showed that the duration and HbA1C level of the patients were the risk factors of DR(P<0.05 to P<0.01),and the 25-OH-VD level was a protective factor of DR(P<0.01).Conclusions:The serum level of 25-OH-VD is associated with the occurrence and severity of DR,and it is an independent risk factor of DR.