Research Update:
Dr. Linda Dodds – Environmental chemicals: what does prenatal exposure mean for future risk of diabetes?
This research grant is funded by the Canadian Diabetes Association
Polly VandenBerg, Manager Research Knowledge Translation
Today, there are more than 9 million Canadians living with diabetes or prediabetes. According to the Canadian Diabetes Association 2008 Clinical Practice Guidelines for the Prevention and Management of Diabetes in Canada, approximately 80 to 90 per cent of people with type 2 diabetes are overweight or obese. Rates of diabetes and obesity have had alarming increases worldwide and are often described as a global epidemic, representing a major threat to human health.
Environmental chemicals which interfere with the body’s hormone system are said to have estrogen-disrupting properties. These chemicals have been associated with the risk of diabetes and are thought to be risk factors for obesity. Although environmental chemicals have been associated with the risk of diabetes, researchers don’t know much about how these chemicals affect the risks of developing diabetes, obesity, and metabolic dysfunction (changes in how the body uses and stores energy) in pregnant women and their children.
Dr. Linda Dodds and her team at Dalhousie University in Halifax are using information that has been collected from a study called Maternal Infant Research on Environmental Chemicals (MIREC). MIREC investigates pregnant women’s risk factors and chemical exposure during pregnancy. Dr. Dodds is also performing new analyses using cord blood samples from the MIREC study to assess the levels of two hormones (called leptin and adiponectin) in the fetus. Both hormones are released from fat cells and are involved in how the body uses and stores energy. This research is funded by the Canadian Diabetes Association from 2011 to 2013.
Dr. Dodds and her team will determine if women who are exposed to higher levels of environmental chemicals also have an increased incidence of abnormal blood glucose levels during pregnancy or gestational diabetes (diabetes during pregnancy). As well, Dr. Dodds and her team will study if higher levels of exposure to environmental chemicals affect a woman’s weight gain during pregnancy. Dr. Dodds will also investigate if these links are modified by factors such as pre-pregnancy body mass index (BMI) or the gender of her child.
Finally, Dr. Dodds’ team will compare various characteristics of infants of women who were exposed to different levels of environmental chemicals. She will determine if the mother’s chemical exposure changes her fetus’s levels of adiponectin and leptin. Dr. Dodds will assess if these relationships are changed by abnormal glucose levels during pregnancy, gestational diabetes, or excessive weight gain, and whether these relationships are changed by the mother’s pre-pregnancy BMI or the gender of her child. These analyses will help to Dr. Dodds figure out if exposure to such environmental chemicals during pregnancy is associated with the child’s future risk of developing diabetes, and childhood risk of obesity and metabolic dysfunction.
The MIREC study database and cord blood bank have described results of exposure to over 80 chemicals and glucose tolerance, pre-pregnancy BMI, and weight gain in the mother, allowing Dr. Dodds and her team to add to this well established national-scale information base. This is the most extensive collection of Canadian data on exposure to certain environmental chemicals during pregnancy, which makes this a unique opportunity to understand potential links between exposure to environmental chemicals and changes in metabolism.
Dr. Dodds’ research will contribute to a better understanding of the effects of environmental exposures during pregnancy, at levels relevant to the general Canadian population. A better understanding of the effects of environmental exposures will allow researchers to assess risks and will allow for appropriate policies to be developed as a result.