Obesity and type 2 diabetes mellitus in a birth cohort of First Nation children born to mothers with pediatric-onset type 2 diabetes.

Children who are born to mothers with pediatric-onset type 2 diabetes mellitus are exposed to a hyperglycemic intra-uterine environment throughout pregnancy. The growth patterns and risk of type 2 diabetes in these offspring may be influenced by unique gene-environment interactions during intra-uterine and postnatal life. We established a cohort of offspring of First Nation mothers with onset of type 2 diabetes before age 18 years in Manitoba, Canada. We measured height or length and weight at study entry and annually thereafter with fasting blood glucose in offspring aged ≥ 7 years. We collected birth and breastfeeding history and determined the population-specific hepatic nuclear factor-1α (HNF-1α) G319S genotype of offspring at age 7 years. From July 2003 to April 2008, we enrolled 76 offspring of 37 mothers. Sixty-four percent (23/36) of the offspring aged 2-19 years were obese at initial assessment. The rates of obesity remained constant throughout the 5 years. As of April 2008, 7/28 (25%) of the offspring aged 7-19 years have diabetes including 6/14 (43%) aged 10-19 years. Most offspring with diabetes (5/7, 71%) were obese at diagnosis. All of the 7 offspring with diabetes have 1 or 2 copies of the G319S polymorphism. The prevalence of type 2 diabetes in this cohort of offspring of First Nation women with pediatric-onset type 2 diabetes is the highest ever reported. Obesity is an important postnatal risk factor for type 2 diabetes in this population and may result from a unique gene-environment interaction.