Type II diabetes mellitus is rapidly becoming a global pandemic with a deleterious impact on cardiovascular morbidity and mortality. Understanding its pathophysiology is important for the development of future therapeutic interventions. Interestingly, mitochondrial dysfunction in skeletal muscle and adipose tissue are early events in the development of type II diabetes mellitus and are proposed to play a role in exacerbating insulin resistance. The genetic disruption of macrophage mitochondrial biology in preclinical studies results in the development of insulin resistance and concurrent mitochondrial dysfunction in peripheral tissue including skeletal muscle and the liver. Whether this disruption of mitochondrial function is evident in human mononuclear cells is unknown. We propose that the disruption of mitochondrial function in circulating cells may contribute to not only peripheral insulin resistance but may also evoke the myriad of vascular complications associated with diabetes.