It's a puzzle that has long plagued scientists: How to easily measure sleepiness before we notice it ourselves. Researchers in labs around the world are making headway and envisioning a future in which testing sleepiness is considered part of general good health.
The hunt is on for a so-called biomarker, a characteristic or substance—or, more likely, several substances—in the body that will indicate if someone is sleepy and, if so, how sleepy. These researchers want to measure acute sleepiness in order to identify the risk of "performance failure" before it happens. That could apply to a morning commuter about to nod off on the freeway, a surgeon preparing for a complicated procedure or a pilot settling into the cockpit before a trans-Atlantic flight.
Research is also looking at chronic sleepiness, which people can feel after just days of less-than-adequate sleep. A growing number of studies have found that not sleeping enough night after night raises the risk of health problems, including obesity, diabetes and heart disease. A biomarker could change the way people view the role sleep plays in their overall health, says Paul J. Shaw, an associate professor of neurobiology at the Washington University School of Medicine in St. Louis. "If people knew they were sleepy, they might say 'I'm going to turn off Leno and go to bed.' "
