09 Jul 2018 --- In the US, about five out of 100 expectant mothers develop gestational diabetes mellitus (GDM), a temporary form of diabetes in which hormonal changes disrupt insulin function. Although GDM is often symptomless and subsides after delivery, women with a history of it face a seven-fold risk for developing type 2 diabetes. Alhough the biological mechanisms underlying this rise in type 2 diabetes risk are mysterious, a new study in Clinical Chemistry led by Deirdre Tobias, DSc., associate epidemiologist at Brigham and Women's Hospital and Assistant Professor at Harvard Medical School, suggests that the irregular metabolism of branched-chain amino acids may be partially to blame for progression to type 2 diabetes.