Determination of oxidative protein and lipid damage in adult hypopituitary patients with GH deficiency.

The aim of this study is to determine oxidative protein and lipid damage in adult hypopituitary GH-deficient patients. Eighteen hypopituitary GH-deficient--otherwise healthy-adults on conventional replacement therapy other than GH (9 male, 9 female, age 41.8 +/- 16.4 yr) and 18 healthy subjects (6 male, 12 female, age 40.3 +/- 16.2 yr) participated in the study. Plasma products of oxidative protein damage [protein carbonyl (PCO) and nitrotyrozine (NT)], plasma oxidized LDL (oxLDL), plasma product of oxidative lipid damage [lipid hydroperoxide (LHP)] and antioxidant status of the plasma [total thiol (T-SH)] were measured. Body fat percentage, total and LDL-cholesterol concentrations were significantly higher in the hypopituitary group. Plasma PCO, NT, LHP and T-SH concentrations did not differ significantly between patients and controls. OxLDL concentration was significantly higher in the hypopituitary patients (62.4 +/- 17.8 vs 43.1 +/- 11.3 U/l, p = 0.001). In the patients, oxLDL correlated significantly with the duration of hypopituitarism (r = 0.6323, p = 0.01). In the controls, oxLDL correlated significantly with blood pressure, total and VLDL-cholesterol concentrations. Increased oxLDL concentration may indicate increased oxidative stress within the vascular compartment and may contribute to the proatherogenic state in GH-deficient hypopituitary patients independent from conventional risk factors.