Diabetes & heart failure: A delicate balancing act

Diabetes and heart failure have a very complex relationship. Having one puts a patient at risk for the other and once a patient has both, his or her condition may spiral quickly in a downward trajectory. In a viewpoint published June 18 in JAMA, physicians discussed concerns and the current state of therapies focused on caring for both diseases.

Diabetes mellitus is a global problem. In the U.S. alone there are 25.6 million adults accruing healthcare costs in excess of $174 billion. Twenty-two percent of older adults with diabetes mellitus have heart failure. In worsening chronic heart failure patients, the proportion of those with diabetes enrolled in studies is 42 percent. Cardiovascular disease is the leading cause of death in diabetes patients, and many are hospitalized or rehospitalized for worsening heart failure and reduced ejection fraction.

“Once heart failure is present in individuals with diabetes mellitus, there is a 10-fold increase in mortality and a 5-year survival rate of only 12.5%, a prognosis worse than metastatic breast cancer,” stated Sadiya S. Khan, MD, of the Center for Cardiovascular Innovation at Northwestern University Feinberg School of Medicine in Chicago, and colleagues.

However, the interaction of these two diseases isn’t generally the focus of studies, according to Khan and colleagues. Most studies focus on one or the other; many diabetes studies exclude patients with heart failure while heart failure studies often leave out systematic evaluations of the effects of the therapies on glucose levels or tolerance.

“The unintended increase in heart failure as a result of thiazolidinedione administration to target increased insulin sensitivity in patients with diabetes mellitus highlights the need to assess heart failure as an endpoint in clinical trials of new agents for diabetes mellitus,” Khan et al wrote.

They went on to state, “The recent concerns related to increased risk of hospitalizations associated with the use of saxagliptin in patients with type 2 diabetes mellitus further reinforces this issue.”

With the number of patients with diabetes growing to pandemic levels, Khan et al stressed the need for future studies to focus on “pathophysiologic abnormalities in the myocardial substrate (eg, metabolic derangements, receptor signaling pathway alterations) specific to heart failure patients with diabetes mellitus, in order to identify unique targets for drug development aimed at improving outcomes in this subset of patients.”