Severe heart damage in people who are obese and diabetic is linked with a pancreatic hormone called amylin, UC Davis researchers have found. In the failing hearts of patients who were obese and diabetic, the scientists discovered strings of proteins, small fibers and plaques made of amylin, the hormone that produces the feeling of being full after eating. They also showed in an animal model that amylin accumulation in the heart leads to heart muscle destruction and failure. Published in the journal Circulation Research, the study also found amylin buildup in overweight patients who are not obese, suggesting the potentially dangerous accumulations may start before a diabetes diagnosis. Heart failure is the number-one killer in obese and diabetic populations. Controlling the circulation of amylin hormone in the blood might lessen or prevent disabilities and deaths from heart disease, the scientists said.