Anti-insulin Antibody Titers Do Not Influence Control or Insulin Requirements in Early Pregnancy

IgG antibodies (AB) to insulin have been reported to influence insulin requirements and control in patients who have taken insulin for prolonged periods of time. Nineteen pregnant type I diabetic patients (C-peptide < 0.03 pmol/ml) were studied in their fifth week of gestation after the establishment of normoglycemia. Mean age was 27.5 yr and duration of diabetes, 14.2 yr (range: 1–23 yr). IgG AB to beef and pork insulin were measured. IgG AB to insulin were encountered in all diabetic patients (range: 103–6736 μU/ml). None of the nondiabetic pregnant controls in their fifth week of gestation (N = 17) had detectable (>50 μU/ml) AB levels. The antibody titer did not affect the insulin requirement (P > 0.2, NS) or ability to achieve normoglycemia. AB levels were correlated with years of treatment with conventional insulin preparations (r = 0.73; P < 0.001). At 5 wk postmenstruation the mean AB level in the patients with less than 10 yr duration of diabetes (N = 7) was 727 μU/ml and mean insulin requirement was 0.7 U/kg/24 h. In the group of patients with greater than 10 yr duration of diabetes (N = 12) the mean antibody titer was 3716 μU/ml and the insulin requirement was also 0.7 U/kg/24 h. IgG AB to insulin increase with increasing duration of treatment with beef/pork insulin. IgG AB do not affect the insulin requirement or the ability to achieve normoglycemia during early pregnancy.