Type 2 diabetes linked to heart disease.
Last month, scientists announced they’ve discovered a direct link between diabetes and heart disease. We’ve long known that having diabetes is a significant independent risk factor for heart disease. Heart disease is already the leading cause of death in the developed world, but people with type 2 diabetes are four times more likely to be diagnosed with heart disease. According to the American Heart Association, about 65 percent of diabetic patients die of cardiovascular disease.
The new research illuminates the precise biological mechanism by which chronic high blood sugar triggers irregular heartbeats, a condition known as cardiac arrhythmia. About once every second, a tiny electrical impulse triggers contraction of the various chambers of the heart in a coordinated manner. Arrhythmias arise when this coordinated activity deteriorates, and the heart fails to contract in a coordinated, efficient manner.
High blood sugar was shown to cause changes in an important enzyme, by altering its structure. The enzyme, CaMKII, helps regulate various aspects of heart function, including its electrical activity. Investigators showed that excess glucose (blood sugar), even at moderate levels, promotes this harmful molecular transformation. The finding underscores the importance of maintaining healthy blood sugar levels. By identifying this mechanism, researchers have provided potential new targets for the development of treatments to reduce the risk of arrhythmias among diabetics.
Jeffrey R. Erickson, Laetitia Pereira, Lianguo Wang, Guanghui Han, Amanda Ferguson, Khanha Dao, Ronald J. Copeland, Florin Despa, Gerald W. Hart, Crystal M. Ripplinger, Donald M. Bers. Diabetic hyperglycaemia activates CaMKII and arrhythmias by O-linked glycosylation. Nature, 2013; DOI: 10.1038/nature12537