Developmental programming of the pancreatic islet by overnutrition.

The Developmental Origins of Health and Disease (DOHaD) Hypothesis postulates that the environment influences postnatal health and plays a role in disease etiology. Studies in both humans and animal models have shown that exposure to either under- or overnutrition results in an increased risk of metabolic disease later in life. In addition, offspring born to overweight or obese mothers are more likely to be obese as children and into early adulthood and to have impaired glucose tolerance as adults. The Centers for Disease Control and Prevention estimates that over 70% of adults over the age of 20 are either overweight or obese and that nearly half of women are either overweight or obese at the time they become pregnant. Thus, the consequences of maternal overnutrition on the developing fetus are likely to be realized in greater numbers in the coming decades. This review will focus specifically on the effects of overnutrition on pancreatic islet development and function and how the resulting morphological and functional changes influence the offspring's risk of developing metabolic disease. We will discuss the advantages and challenges of different animal models, the effects of exposure to overnutrition during distinct periods of development, the similarities and differences between and within model systems, and potential mechanisms and future directions in understanding how developmental alterations due to maternal diet exposure influence islet health and function later in life.