Paraoxonase is reduced in patients with GH deficiency: a risk factor for atherosclerosis?
Fahri Bayram1, Gulden Baskol2, Fatih Tanriverdi1, Derya Kocer2 & Ilkay Cakir1
Objective: GH deficiency is associated with an increased cardiovascular mortality. Increased oxidative stress has been associated with development of cardiovascular and cerebrovascular diseases. In the present study, we aimed to determine i) serum PON1 activities, an established lipid antioxidant, ii) MDA levels which are end products of lipid peroxidation induced by ROS and iii) thiol groups as an antioxidant for evaluating oxidative stress in patients with GHD before and after GH replacement therapy.
Methods: Fourteen patients with GHD were included in the study and compared with healthy controls (n=14). The patients were compared with 14 healthy controls who were matched for age and sex. Serum paraoxonase 1 activity, malondialdehyde and thiol levels were measured according to an enzymatic spectrophotometric method.
Results: MDA levels were found as higher in the pre-treatment GHD according to both post-treatment GHD and controls. MDA levels were also found to be decreased in post-treatment GHD than in pre-treatment GHD. PON1 activity was found to be lower in pre-treatment patient group when compared to both post-treatment GHD and controls. Thiol levels were found to be lower in GHD patients in the pre-treatment group when compared to control.
Conclusions: Increased ROS levels in GHD may result in a pro-oxidation environment, which in turn could result in decreased antioxidant PON1 activity and thiol levels and increased MDA levels; as a result, decrease in blood PON1 activity and increased lipid peroxidation may have role in the pathogenesis of the atherosclerosis and cardiovascular disease in patients with GHD.