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. (C) 2003, Editrice Kurtis.