['Hydrogen peroxide is enzymatically processed by catalase, and catalase deficiency in blood is known as acatalasemia. We examined whether low catalase activity is a risk factor for diabetes mellitus.', 'Blood glucose, insulin and glucose tolerance test were examined in acatalasemic and normal mice under non-stress and oxidative stress conditions. Alloxan administration was used as oxidative stress.', 'Alloxan, which was a drug that caused diabetes mellitus, mostly generated hydrogen peroxide by the reaction of alloxan and reduced glutathione, in vitro. Incidence of hyperglycemia in alloxan-untreated acatalasemic mice was as low as that in the normal mice. However, the incidence of acatalasemia mice treated with alloxan was higher than that in normal mice, and the number of pancreatic beta-cells in the acatalasemic mice was less than that in normal mice.'] Is low catalase activity in blood associated with the diabetes caused by alloxan?