Blood pressure is a risk factor for progression of diabetic retinopathy in normotensive patients with type 2 diabetes: correlation with carotid intima-media thickness.

OBJECTIVE

Carotid atherosclerotic lesions have been described more frequently in patients with diabetes and microvascular disease than in those with uncomplicated diabetes. In this study, we investigated the role of blood pressure as a risk factor of diabetic retinopathy in normotensive patients with type 2 diabetes. We also assessed the correlation of carotid intima-media thickness with both blood pressure and diabetic retinopathy.

METHODS

The study group consisted of 140 normotensive patients (68 males and 72 females) with type 2 diabetes and diabetic retinopathy. Carotid intima-media thickness was evaluated using high-resolution B-mode ultrasonography. Diabetic retinopathy was assessed and graded, using colored fundus photography and fundus fluorescein angiography, as either non-proliferative or proliferative.

RESULTS

Patients with proliferative diabetic retinopathy showed a higher systolic and diastolic blood pressure (p<0.01). Carotid intima-media thickness was higher in patients with proliferative than non-proliferative diabetic retinopathy ones (1.094 ± 0.142 vs. 0.842 ± 0.134 mm, respectively; p<0.001) Carotid intima-media thickness showed positive correlation with both systolic (p<0.001) and diastolic blood pressures (p<0.01). No significant differences were found between males and females in any of the studied parameters.

CONCLUSION

Our study proves that both systolic and diastolic blood pressures are important risk factors for the progression of retinopathy in normotensive patients with type 2 diabetes. We also demonstrate that carotid intima-media thickness, as a marker of atherosclerosis, is strongly correlated with both blood pressure and diabetic retinopathy in those patients.