Unexpected lower prevalence of HBsAg in diabetics than in controls. (A study on 2,465 patients).

Serum samples from 2,465 diabetics were examined by radioimmunoassay for HBsAg, anti-HBs and anti-HBc at the Centro Antidiabetico of the Ospedale Maggiore di Lodi; during the same period, the same tests were carried out on serum samples from 2,176 control subjects, who had been admitted to the surgical, casualty and obstetrical departments for reasons that had nothing whatsoever to do with any form of liver disease. The ages of the two groups ranged from 6 to 90 years. The diabetics were divided into three groups; insulin-dependent, non-insulin-dependent and diabetics treated with insulin for diabetic complications. The overall frequency of HBsAg in the various groups of diabetics was 3.5%, while in the controls it was 6.1% (p less than 0.001). In the group of young insulin-dependent diabetics, the frequency was 1.7%, as compared to 6.9% for the controls in the same age group (p less than 0.05). In the group of patients treated with insulin for diabetic complications, the frequency increased to 11.5%, while for the controls in the same age group it was 5.5%. The levels of HBsAg were practically the same in the diabetics and in the controls, whereas the level of anti-HBc was higher in the diabetics: 55.6% compared to 50% (p less than 0.005). This last result indicates that the chances of hepatitis B virus infection were greater for the diabetics than for the controls. Diabetics, and especially those insulin-dependent are, therefore, believed to possess a greater capacity of resistance through their T cell-mediated immune response to the hepatitis B virus.