Diabetes, Vol 42, Issue 10 1433-1439, Copyright © 1993 by American Diabetes Association
Decreased risk of type I diabetes in offspring of mothers who acquire diabetes during adrenarchy
D Bleich, M Polak, GS Eisenbarth and RA Jackson
Division of Immunology and Immunogenetics, Joslin Diabetes Center, Boston, Massachusetts.
Fathers with type I diabetes transmit diabetes to their offspring 2-3 times
more frequently than mothers with type I diabetes. This phenomenon has
provoked both genetic and nongenetic hypotheses, but the mechanism remains
obscure. We find that mothers who develop diabetes before age 8 transmit
diabetes at the same rate as diabetic fathers, and that the sex difference
in diabetes transmission is explained by a decreased transmission rate in
mothers who acquired diabetes after age 8. We constructed a data base
containing 2156 nondiabetic and diabetic offspring of parents with type I
diabetes. Families were selected from our main data base, which contains
demographic information and diabetes autoantibody test results on > 8000
first-degree relatives of patients with type I diabetes and diabetic
probands. Identification of offspring was made through diabetic parents who
had participated in our autoantibody screening program at the Joslin
Diabetes Center between 1983 and 1990. Questionnaires were sent to all
other family members to determine the number of diabetic and nondiabetic
offspring in each family. The 20-yr life-table risk of diabetes in
offspring of diabetic fathers and mothers is 8.9 +/- 1.0 and 3.4 +/- 0.6%,
respectively. For mothers acquiring diabetes before or after age 8, the
risk of diabetes in offspring is 13.9 +/- 4.4 and 2.4 +/- 0.6% at 20 yr of
age, respectively. Furthermore, we find that duration of diabetes in
mothers before pregnancy has no effect on the risk of diabetes in their
offspring.(ABSTRACT TRUNCATED AT 250 WORDS)