Minimizing Postprandial Oxidative Stress in Type 2 Diabetes: The Role of Exercise and Selected Nutrients

Approximately 25.8 million Americans (8.3% of the population) are currently living with diagnosed (18.8 million) or undiagnosed (7.0 million) diabetes (World Health Organization, 2011), most of whom are type 2 in pathology. An additional 79 million Americans are estimated to have pre-diabetes (World Health Organization, 2011). Unfortunately, the overall prevalence of these conditions continues to rise, as indicated by the 1.9 million newly diagnosed cases of diabetes in 2010 within people aged 20 years and older (World Health Organization, 2011). A similar situation presents itself within other nations around the world, with an estimated 220 million individuals currently living with diabetes (World Health Organization, 2011). The onset and progression of diabetic disorders, as well as the related complications, are linked to impairments in glucose and lipid metabolism (O'Keefe & Bell, 2007), both of which are strongly associated with increased production of reactive oxygen and nitrogen species (RONS) (Ceriello & Motz, 2004; Fisher-Wellman & Bloomer, 2009b). Increased RONS production coupled with impaired antioxidant defense (a common finding among patients with diabetes) promotes oxidation of specific biomolecules (e.g., lipids, proteins, DNA), which can lead to an exacerbation of diabetic complications (Giacco & Brownlee, 2010). While variables such as blood glucose and blood triglycerides have traditionally been measured in a fasted state, increasing evidence suggests that measurement of postprandial glycemia, lipemia, as well as oxidative stress biomarkers, may provide more important clinical information concerning an individual’s susceptibility to both type 2 diabetes mellitus (T2DM) onset and disease progression—as well as related conditions (O'Keefe & Bell, 2007; Pastromas et al., 2008). For example, increased postprandial oxidative stress has been implicated in the pathophysiology of diabetes (Wright et al., 2006) and cardiovascular disease (Ceriello, 2004), which may be linked to the strong association between the postprandial rise in blood glucose and triglycerides and the generation of RONS. Moreover, randomized controlled trials indicate that reducing postprandial triglycerides appears to slow atherosclerotic progression and may improve long-term cardiovascular prognosis (O'Keefe & Bell, 2007). Therefore, methods to reduce the postprandial rise in glycemia and lipemia may help to prevent oxidative stress related complications in T2DM patients.