News & Research
Michael Freemark MD – Duke University Medical Center
Gestational diabetes affects about 2% to 5% of all pregnancies, a small percentage for a significant problem. Gestational diabetes is described as the development of high blood sugar in pregnant women with no previous history or diagnosis of diabetes mellitus. There are no known specific causes of this pregnancy complication, however, the American Diabetes Association is providing funding to a researcher who is currently investigating and attempting to find the answers.
Meet Michael Freemark, MD, the recipient of a Basic Science Award. His research project is entitled, “Beta Cell growth and function during pregnancy: The interactions of glucocorticoids, cytokines, and lactogenic hormones.” Dr. Freemark states, “Our study should help us understand how a mother maintains normal blood sugar during pregnancy while supplying the nutrients that are essential for fetal development and growth.”
Previous hypotheses suggest that hormones known to induce breast development and lactation (the lactogenic hormones) also cause insulin resistance during the late stages of pregnancy. These hormones are known as placental lactogen (PL) and prolactin (PRL). But an alternate hypothesis presented by Dr. Freemark suggests that the lactogenic hormones associated with pregnancy could actually protect against the development of gestational diabetes.
During his first year of Association-funded research, Dr. Freemark has made considerable progress in support of his hypothesis. He has worked with genetically mutated rodents whose islets are resistant to the effects of the lactogenic hormones. Study results demonstrated that prolactin stimulates insulin production by increasing the number of islet beta cells, increasing their production of insulin, and prolonging beta cell survival. This action occurred by suppression of a critical metabolic regulator, FoxO1, and by increasing the activity of an enzyme called pyruvate dehydrogenase.
Dr. Freemark’s research will have important implications in the field of diabetes by developing a fundamental understanding of the roles of hormones and nutrients which may enable the prevention or treatment of gestational diabetes. In the long-term, this research may help limit the danger to developing infants and reduce their long-term risks of obesity and type 2 diabetes.
Finally, the studies could determine why most pregnant women do not develop gestational diabetes. Overall, this may provide a new approach to preventing and treating diabetes in men, non pregnant women and children. Overall, Dr. Freemark describes his research focus as being, “integral to the mission of the Association."
