Always-on stress hormones encourage adipose production
SAN DIEGO — New research may help explain why chronic stress, sleep deprivation and other disruptions in the body’s daily rhythms are linked to obesity.
Chronic exposure to stress hormones stimulates growth of fat cells, Mary Teruel of Stanford University reported December 16 at the annual meeting of the American Society for Cell Biology. Normally, stress hormones, such as cortisol, are released during waking hours in regular bursts that follow daily, or circadian, rhythms. Those regular pulses don’t cause fat growth, Teruel and colleagues discovered. But extended periods of exposure to the hormones, caused by such things as too little sleep, break up that rhythm and lead to more fat cells.
Even though only about 10 percent of fat cells are replaced each year, the body maintains a pool of prefat cells that are poised to turn into fat. “If they all differentiated at once