Antibodies against oxidised low-density lipoprotein in hypopituitary patients with growth hormone deficiency

Abstract

Growth hormone-deficient hypopituitary patients on conventional replacement therapy have increased mortality and morbidity from atherosclerotic cardiovascular disease. Oxidation of low-density lipoprotein (LDL) is a key event in the development and progression of atherosclerosis. Antibodies against oxidatively modified LDL may reflect in vivo oxidation processes. The aim of this study is to determine the effect of growth hormone deficiency on oxidised-LDL antibody titres in panhypopituitary patients taking conventional replacement therapy. Twenty-one GH deficient, adult panhypopituitary patients and 17 age, sex and body mass index-matched healthy controls were studied. After an overnight fast, anthropometric parameters were measured and body composition was determined by a bioelectrical impedance analyser. Venous blood samples were obtained for the measurements of biochemical parameters. Antibodies to oxidised-LDL were analysed by an ELISA system in the patients' and controls' serum. No significant difference was observed between the oxidised-LDL antibody titres in hypopituitary patients and controls (395.4 +/- 183.2 mU/ml and 393.2 +/- 186.2 mU/ml respectively, p=NS). A. significant positive correlation was observed between oxidised-LDL antibody titres and total cholesterol concentrations in the patients (r=0.449, p <0.05). No significant correlation was observed between oxidised-LDL antibody titres and anthropometric/biochemical variables in the controls. It is concluded that relatively increased LDL oxidation may not contribute to the progression of atherosclerosis in hypopituitary patients.