Influence of ozone on haemoglobin oxygen affinity in type-2 diabetic patients with peripheral vascular disease: in vitro studies. Coppola L; Giunta R; Verrazzo G; Luongo C; Sammartino A; Vicario C; Giugliano D Department of Gerontology, Geriatrics and Metabolic Diseases, Second University of Naples, Italy. Diabete Metab, 21: 4, 1995 Oct, 252-5 Abstract The use of ozone in the treatment of peripheral vascular disease (PVD) is increasing. The purpose of this study was to evaluate the effect of ozone on haemoglobin oxygen affinity in Type-2 diabetic patients with PVD. Twenty diabetic patients presenting with PVD (Clinical stage II-IV according to Fontaine) and 20 non-diabetic healthy matched subjects were studied. In both groups, aliquots of blood were ozonised with mixtures of oxygen-ozone (O2-O3) to reach end-concentrations of 6.5, 13, 26 and 78 micrograms O3 per ml of substrate. At baseline, diabetic patients presented significantly lower haemoglobin oxygen affinity values but higher plasma levels of free haemoglobin and malonyldialdehyde (MDA) than controls. In both diabetic patients and controls, exposure of blood to ozone reduced haemoglobin oxygen affinity in an "all-or-none" fashion, without changing 2-3, diphosphoglycerate concentrations in erythrocytes. Both free haemoglobin and MDA concentrations showed significant, dose-dependent increases after blood ozonisation. Thus, ozone caused a significant increase in oxygen unloading of haemoglobin in both normal subjects and Type-2 diabetic patients with PVD.