ALEXANDRIA, Virgina: Often known as "the silent killer," diabetes may soon have one fewer place to hide. In an effort to identify the estimated 8 million Americans who have the disease but don't know it, the American Diabetes Association has called for all adults 45 and older to be tested for adult-onset diabetes every three years. The Association also dramatically lowered the blood glucose threshold that alerts doctors to the disease. Previously, "normal" glucose levels were at least 140 milligrams per decileter of blood plasma. New research shows that repeated blood sugar levels of as low as 126 milligrams can later set off a string of potentially life-threatening, complications ranging from heart disease to kidney failure. By detecting the disease early on, doctors could help reduce what is currently the number-four cause of death in the U.S., the new guidelines say.