ABSTRACT
With the invention of the light bulb and ready availability of electrical power, sleep loss has become increasingly prevalent in industrialized nations. Air travel across multiple time zones, globalization of commercial markets, shift work, 24/7 services, television, and the Internet have contributed to longer waking hours and reduced sleep. The mean number of hours of nocturnal sleep has fallen steadily in the last century from about 9 to 6.9 hours in 2005, based on the most recent National Sleep Foundation Poll (1). The proportion of Americans sleeping 8 or more hours on weekday nights has fallen steadily from 38% in 2001 to 26% in 2005. Therefore, sleep deprivation (SD) has become one of the most important yet understated public health issues of modern times.
