NPPB and diabetes mellitus: We studied 303 moderate- to high-risk patients undergoing surgery for ischemic heart disease (age 74 ± 7 years; females 26%, diabetes 47%) who were randomized to blinded infusion of intravenous glutamate or saline, and used the difference between preoperative and day-3 postoperative NT-proBNP levels as the primary endpoint.