Estado oxidativo-metabólico y afectación retiniana en diabetes mellitus e hipertensión arterial. Seguimiento a cinco años.

Zusammenfassung

In this study, the role of oxidative stress and the antioxidant supplementation with an oral vitaminic-mineral complex (nutritional doses) are analyzed in groups of diabetic, hypertensive and healthy subjects, emphasizing in the assessment of mild and moderate diabetic and hypertensive retinopathies in a five-year follow-up. With this aim a total pool of 604 subjects were recruited in 1999 (distributed in diabetic, hypertensive and healthy group). A detailed anamnesis (including possible risk factors of retinopathy), diastolic blood pressure (DBP) assessment, a complete ophthalmic check-up and a blood determination of classic parameters (glucaemia, glycated hemoglobina, total colesterol, HDL, LDL, urea and creatinine) and parameters of the oxidative status (malonyldialdehyde (MDA), total antioxidant status (TAS) and superoxide dismutase activity). A part of the simple was supplemented with antioxidants. Annual assessments were performed in order to detect clinical changes, reinforce the ingestion of the supplement and check possible changes in address and phone numbers. A total of 490 subjects were followed in five years. An anamnesis, clinical and a blood analysis identical that the performed at the beginning were carried-out at the end of the follow-up (2004). The imbalance of oxidative activity was altered in the diabetic and hypertension groups compared to healthy group, in favour of oxidative stress. Correlation studies were performed and we obtained a significant association between the duration of the disease and retinopathy grade, MDA and glucose and MDA and blood total cholesterol. It was also found that the increase of oxidative activity and a decrease of antioxidant activity were related to the severity progression of diabetic and hypertensive retinopathies although levels of biochemical markers of oxidative stress were not associated with the severity stage of ocular damage. Average best-corrected visual acuity and DBP did not change during the follow-up, independently of supplementation. However, the stage of retinopathy (diabetic and hypertensive) remained stable in groups and subgroups with supplementation and worsened in groups without antioxidant supplementation. Furthermore, antioxidant supplementation maintained the antioxidant plasmatic status and was related with the decrease of pro-oxidative plasmatic activity.