title: Paraoxonase is reduced in patients with growth hormone deficiency: A novel risk factor for atherosclerosis.
abstract: BACKGROUND
  Growth hormone deficiency (GHD) 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 evaluate oxidant and antioxidant status in patients with GHD by analyzing serum paraoxonase1 (PON1) activity, and malondialdehyde (MDA) and thiol levels.
  
  
  METHODS
  This study was a case-control study. Thirty patients with GHD were included in the study and compared with 20 healthy controls. Serum PON1 activity, and MDA and thiol levels were measured according to an enzymatic spectrophotometric method.
  
  
  RESULTS
  Serum MDA levels (2.8 ± 1.3 nmol/mL) were higher in GHD group than the controls (1.7 ± 0.5 nmol/mL) (P = 0.001). PON1 activity (149.9 ± 77.9 U/L) was lower in GHD group than the controls (286.3 ± 126.7 U/L) (P = 0.001). Thiol and high-density lipoprotein cholesterol (HDL-cholesterol) levels were lower in GHD group (218.6 ± 103.9 µmol/L and 32.6 ± 13.4 mg/dL, respectively) than the controls (289.6 ± 101.1 µmol/L and 54.3 ± 14.9 mg/dL, respectively) (P = 0.021 and P = 0.001, respectively). In GHD patients, serum MDA level was negatively correlated with serum HDL-cholesterol (r = -0.499, P = 0.001), and serum PON1 activity was positively correlated with serum thiol and HDL-cholesterol levels (r = 0.306, P = 0.032 and r = 0.303, P = 0.033, respectively).
  
  
  CONCLUSIONS
  These data support that GHD is characterized by an imbalance between oxidant and antioxidant factors. This abnormality may contribute to the increased atherogenic risk in patients with GHD.
authors.affiliation: Department of Endocrinology and Metabolism, Erciyes University Faculty of Medicine, Kayseri, Turkey.
authors.forename: Fahri
authors.initials: F
authors.lastname: Bayram
authors.forename: Gulden
authors.initials: G
authors.lastname: Baskol
authors.forename: Fatih
authors.initials: F
authors.lastname: Tanriverdi
authors.forename: Mevlut
authors.initials: M
authors.lastname: Baskol
authors.forename: Derya
authors.initials: D
authors.lastname: Kocer
authors.forename: Ayşen
authors.initials: A
authors.lastname: Caniklioğlu
keywords: Growth hormone deficiency; malondialdehyde; oxidative stress; paraoxonase