Late Metabolic Effects of Metformin Therapy in Gestational Diabetes

Gestational diabetes is usually managed with diet and insulin, if needed. However, oral metformin therapy has been also used to treat gestational diabetes and the short-term studies have shown that it is effective and also safe for the child. However, long-term studies of its effects are lacking.

Previously, several years ago, 217 pregnant women with gestational diabetes in Turku and 100 such women in Oulu, Finland, were randomised to either insulin or metformin therapy to treat gestational diabetes. In those studies, the metformin therapy proved to be safe in the short-term.

Now these children are 5-9 years old. In the present study these children (as well as their mothers) are investigated when the children are 9 years old. The aim is to study whether the metformin given during the pregnancy has any metabolic effects on the child at 9 years of age. To do this these families are contacted by mail and asked to participate into the study.

At 9 years of age, the following investigations will be made (after consent from the child and family): oral glucose tolerance test+insulin+c-peptide, plasma lipoproteins, adiponectin, PAI-1 (plasminogen activator inhibitor-1), IL-6 (interleukin-6), HS CRP (high-sensitivity C-reactive protein), p-metabolomics, DEXA, abdominal MRI, WISC IV (Wechsler intelligence scale for children IV)cognitive testing, BRIEF questionnaire, questionnaire about diet and health habits. The study subjects will also be clinically examined and measured and blood pressure will be taken.

All analyses are performed at the University hospital laboratory and radiology facilities using modern techniques. The amount of blood taken is limited and also radiation dose from DEXA is very small. The data are kept behind lock and key. Statistical analyses will be performed to study whether children exposed to metformin during pregnancy have any differences in their metabolism and well-being than those exposed to insulin. This study involves no new medical treatments to the study subjects.

Inclusion criteria

• all children whose mothers used either metformin or insulin to treat gestational diabetes and were involved in the previous metformin study in Turku or Oulu, Finland

Exclusion criteria

• severe congenital malformations