Background and Significance: The prevalence of type II-diabetes mellitus is increasing in the United States (U.S.) and was estimated to affect 29.1 million Americans in 2012. Several factors including genetics, insulin resistance, and decreased β cell mass can lead to the development of type II-diabetes. Nonetheless, interventions that target the early stages of its pathogenesis (i.e. pre-diabetes) before individuals are diagnosed with type II-diabetes would be ideal for preventing its development. Without appropriate interventions, pre-diabetes is typically followed by type II-diabetes mellitus at an annual rate of about 10%. The influence of diet on the development of type II-diabetes mellitus has been studied for years; however, it is necessary to find dietary interventions that will effectively reduce the risk of type II-diabetes especially in those who are at a higher risk such as overweight and obese individuals. Eggs are rich source of important nutrients including proteins, vitamins, e.g. A, E, and B12, minerals, carotenoids, and lecithin. Although there are studies that have demonstrated the ability of egg consumption to improve glycemic control, insulin sensitivity, and lipid profile, there is a lack of such studies in pre-diabetes as well as early stages of type II-diabetes and hence is the reason for this dissertation project. Methods: A total of 50 individuals between the ages of 40 to 75 years who are overweight or obese and have pre- and type II-diabetes were included in this 12-week, parallel, randomized intervention study. Subjects were randomly assigned to receive either: 1) one large egg per day to be incorporated into their usual diets for 12 weeks; or 2) control in which participants received an equivalent amount of egg substitute in terms of calories (3/4 cup liquid egg substitute per day) incorporated into their usual diets for 12 weeks. Serum and plasma samples were analyzed for TC, HDL-C, LDL-C, TG levels, apoA1, fasting blood glucose levels, insulin levels, and ABCA1 levels at baseline, 6- and 12-week. Body composition including percent fat mass, fat free mass, as well as android/gynoid ratio were assessed using DXA at baseline, 6- and 12-week. Questionnaires were used for monitoring dietary and physical activity patterns over the 12 weeks of the study. Analyses were performed for the 40 subjects who completed the entire study. Results: Self-reported compliance with the regiments were reported to be excellent and the retention of participants was high. Based on the self-reported food records, there were no significant differences in the food intake between the egg group and control. Also, there were no significant differences between the two groups in physical activity levels. There were no significant differences in weight, waist and hip circumferences between the two groups. The results from DXA scan showed that android fat was significantly lower at all visits in the egg group (P=0.05, 0.02, and 0.01); however, this result cannot be attributed to the consumption of eggs. Daily intake of egg resulted in improvements of blood glucose levels which was significantly lower at final visit in the egg group (P=0.05). Participants in the egg group had significantly lower levels of HOMA-IR at all visits (P=0.01). Additionally, insulin levels in the egg group was significantly lower at baseline and 6-week visits (P=0.01). However, none of these changes can be attributed to the treatment effects. There were no significant differences within and between groups for the calculated HOMA-β values. HDL-C levels were significantly higher for all visits in the egg group versus the control (P<0.001). Additionally, in the egg group, ABCA1 protein was significantly higher at the 6-week visit (0.78±0.21 mg/dL vs 0.28±0.05, P<0.001) and tended to be higher at the final visit (0.62±0.11 vs 0.55±0.18, P=0.1). Additionally, apoA1 levels was significantly higher at final visit in the egg group compared to the control (147.43±5.34 vs 142.81±5.09, P=0.01). There were no significant changes in total cholesterol and LDL-C levels. Discussion: The findings of this study suggest that daily consumption of egg may decrease diabetes risk factors without having any adverse effects on lipid profiles in diabetic individuals.
