The past few years have witnessed an enormous growth in the scale of scientific activity devoted to assessing the possible link between sleep apnea and disorders of glucose metabolism. The explosion in research and clinical interest has been driven by the demonstration that short sleep duration can lead to glucose intolerance and insulin resistance. Subsequently a number of studies have provided support for an independent association between disorders such as sleep apnea, chronic sleep loss, and insomnia with metabolic dysfunction. The current article summarizes the literature implicating sleep apnea as an independent risk factor for abnormalities in glucose metabolism and discusses the possible physiological role of sleep fragmentation and intermittent hypoxemia as putative intermediates.