Poorer physical fitness is associated with reduced structural brain integrity in heart failure

Objective Physical fitness is an important correlate of structural and functional integrity of the brain in healthy adults. In heart failure (HF) patients, poor physical fitness may contribute to cognitive dysfunction and we examined the unique contribution of physical fitness to brain structural integrity among patients with HF. Methods Sixty-nine HF patients performed the Modified Mini Mental State examination (3MS) and underwent brain magnetic resonance imaging. All participants completed the 2-minute step test (2MST), a brief measure of physical fitness. We examined the associations between cognitive performance, physical fitness, and three indices of global brain integrity: total cortical gray matter volume, total white matter volume, and whole brain cortical thickness. Results Regression analyses adjusting for demographic characteristics, medical variables (e.g., left ventricular ejection fraction), and intracranial volume revealed reduced performance on the 2MST were associated with decreased gray matter volume and thinner cortex (p <.05). Follow up analyses showed that reduced gray matter volume and decreased cortical thickness were associated with poorer 3MS scores (p <.05). Conclusions Poor physical fitness is common in HF and associated with reduced structural brain integrity. Prospective studies are needed to elucidate underlying mechanisms for the influence of physical fitness on brain health in HF.