WASHINGTON - Disrupted sleep hurts the body's ability to regulate blood sugar levels, possibly increasing the risk of Type 2 diabetes, say researchers at the University of Chicago Medical Center. In a Jan. 2 report issued in the online edition of Proceedings of the National Academy of Sciences, the researchers studied the sleep patterns of nine volunteers, five men and four women, all of normal weight, in good health and ages 20 to 31. When the volunteers went into slow-wave sleep--the deepest level of sleep--the researchers made enough noise to disturb the sleep but not to awaken them fully. After three days, the ability of the volunteers to regulate blood sugar was reduced by 25%, the researchers reported.