In data from prospective cohort studies, self report of insufficient or disturbed sleep is related to increased overall and cardiovascular morbidity. Inflammation is established as a key mechanism in the development of arteriosclerotic heart and vascular disease. Inflammation has been considered a possible link between short sleep and cardiovascular disease and morbidity. Measures of inflammation are increased by experimental sleep deprivation, but in cohort studies a relationship of sleep duration to inflammatory markers is less clear. In these studies the association of self reported short sleep to cardiac morbidity is confounded by many psychological and socioeconomic variables. More studies are needed to explain the link between short sleep duration and cardiac morbidity. Experimental studies of sleep deprivation mimicking habitual shortened sleep over long time intervals, and studies employing sleep extension in habitual short sleepers will allow better characterization of the health benefits of adequate sleep duration. Prospective cohort studies should include objective measures of sleep duration and should to control for the known confounding variables.