[Diabetic retinopathy and associated conditions, what relationship? A study in Portuguese patients with type 2...

Diabetic retinopathy is the leading cause of blindness in adults in Western countries. There are few studies about this microvascular complication in the Portuguese population. The aim of the present study is to establish the relationship between diabetic retinopathy, risk factors and associated conditions, in a group of patients with type 2 diabetes mellitus.

We performed a descriptive, transversal and case-control study that included 874 patients - 437 with and 437 without diabetic retinopathy, respectively. Data were collected from electronic medical records, in the Portuguese Diabetes Association with a first consult of Diabetology.

The group with retinopathy had significantly higher values of HbA1c, systolic blood pressure and years of diagnosis, compared with the group without retinopathy (p<0.05). Regarding the levels of HbA1c, both groups showed more than 70% of patients outside the target value (HbA1c>6.5%) but in the subgroup with retinopathy, the percentage of patients in these conditions was higher (91.3%) compared to control group (73.2%) (p<0.05). The prevalence of hypertension in the sample was 73%. It was found that the group with retinopathy had a significantly higher prevalence of hypertensive patients (79.6% versus 66.4%) (p<0.05). The prevalence of nephropathy was higher in the group with retinopathy (35.6% versus 0.8%) (p<0.05).

There is a positive correlation between retinopathy and hypertension, glycaemic control and nephropathy. Thus, it is extremely important to control blood pressure and to educate patients about the benefits of a good glycaemic level.