Blood ALDH1 and GST Activity in Diabetes Type 2 and its Correlation with Glycated Hemoglobin

There is increasing evidence that oxidative stress (OS) plays a major role in the pathogenesis of diabetes mellitus (DM) and the development of its complications. As one of the consequences of OS is increased lipid peroxidation (LP), the aim of our studies was to check, how the activity of 2 enzymes involved in the detoxification of aldehydes formed during LP, glutathione S-transferase (GST) and aldehyde dehydrogenase 1 (ALDH 1) is changed in patients suffering from DM. GST and ALDH1A1 activities were determined in whole blood samples of DM type 2 patients (n = 64) and healthy controls (n = 60) using spectrophotometer (for GST activity) and fluorometer (for ALDH1 activity) and they were found to be significantly increased in diabetics when compared with healthy control (p < 0.05). Intriguingly, grouping the DM patients on the basis of the glucose level and HbA1c revealed unusually low ALDH activity in the group of patients (n = 16) with a relatively high level of these 2 parameters. The increase of ALDH1A1 and GST activity in DM seems to be associated with the severity of the disease and might be a compensatory effect against oxidative stress. Surprisingly low ALDH activity in DM patients with relatively high glucose and HbA1c levels can be a factor predisposing to the development of diabetic complications.