Grant: Operating Grant

Coronary artery disease (CAD) involves hardening and clogging of the arteries supplying blood to the heart. Many studies have shown that those with CAD have a more rapid decline in memory than expected and that they are at an increased risk of developing dementia. In patients with CAD, memory changes also have important immediate consequences: they are associated with physical disability, unemployment, poorer quality of life and more medical complications causing dropout from cardiac rehabilitation. It is not understood how memory decline is linked to CAD; however, it has recently been discovered that certain byproducts of fat breakdown involved in the development of CAD, called ceramides, can harm brain cells. Ceramides are overproduced in response to inflammation, a key feature of CAD. Also, inflammation has been associated with poorer memory performance in those with CAD. Taken together, this evidence suggests that ceramides may be the link between CAD and memory decline. We hypothesize that ceramide production will be associated with more memory decline over 1 year in CAD patients. To test this, we will recruit 129 CAD patients from a cardiac rehabilitation facility and measure memory performance and blood ceramide concentrations at baseline, 6 and 12 months. We will also measure important blood messengers of inflammation and assess whether they are associated with ceramide production. In addition, relationships between ceramides and other aspects of brain function, such as thinking speed and the ability to plan and sort information will be explored. As a greater proportion of Canadians reach older ages, there is a pressing need to maintain cognitive function later in life. The knowledge from this study may be the key to developing new treatments targeting memory decline in patients with CAD. New treatments based on relevant mechanisms might not only improve memory and quality of life, but also reduce mortality and the odds of developing dementia.