A study shows that people who sleep fewer than six hours a night are 12 percent more likely to die early than those who sleep six to eight hours every night, report UTMB’s Norbert Herzog and David Niesel in this week’s installment of Medical Discovery News. “Researchers compiled and analyzed data from 16 studies in Europe, Asia and the U.S., covering 25 years, 1.3 million people and over 100,000 deaths. ... While scientists are still figuring out why we need sleep, animal studies show it’s necessary for survival. Sleep is essential for well functioning immune and nervous systems.” MDN airs locally at 10 a.m. Saturday on KUHF.