Cardiovascular involvement in glycogen storage diseases.

Glycogen storage diseases are rare conditions affecting both sexes that are caused by inherited deficiencies of enzymes involved either in glycogen synthesis or breakdown, or in glycolysis. The liver and skeletal muscle are usually the most affected tissues. However, because glycogen has an important role in cardiac development and function, several glycogen storage diseases are associated, at least indirectly, with cardiac disorders, some of which have severe consequences from the first months of life. Early identification of these conditions is, therefore, an important issue, and implementation of strategies to prevent fatal outcomes due to cardiovascular disease is vital. In this Review, we discuss the pathophysiological mechanisms and the preclinical, clinical and epidemiological evidence for cardiovascular involvement in various glycogen storage diseases. We also describe interventions that can help preserve heart function, including changes in nutrition and exercise, as well as the few available molecular therapies to address the underlying metabolic anomalies.