Hypertension strengthens δ-ALA-D activity inhibition and increases it reactivation index in type 2 diabetic patients

Aims: To assess the effect of hypertension on delta-aminolevulinate dehydratase (delta-ALA-D) activity of type 2 diabetic patients (T2DM). Methods: delta-ALA-D activity and reactivation index, as well as markers of oxidative stress, biochemical and anthropometrics parameters were determined in T2DM (n = 23), type 2 diabetic patients with hypertension (T2DM/HT) (n = 30) and controls (n = 30). Results: T2DM/HT presented a greater inhibition of delta-ALA-D activity, a higher reactivation index (p<0.05) and a greater depletion of plasma protein thiol groups (P-SH) when compared to T2DM. Moreover, delta-ALA-D activity was positively associated with SH groups and negatively associated with serum protein carbonyl (PC) while its reactivation index was negatively associated with SH groups and positively associated with PC. Conclusions: These results point out that there is a possible interference of hypertension on the mechanism of the delta-ALA-D activity suggesting that this condition aggravated the oxidative stress of diabetes mellitus. (C) 2012 Elsevier Inc. All rights reserved.