Lifestyles, Left Atrial Structure and Function, and Cognitive Decline in Adults with Metabolic Syndrome

Evidence supports associations of lifestyle (including diet and physical activity) and weight with cognitive functioning, but the pathways responsible for these associations have not been fully elucidated. Because healthier lifestyles have been associated with better left atrial structure and function, which in turn is associated with better cognitive functioning, we tested the hypothesis that left atrial structure and function is a potential mediator of the association between lifestyle and cognition. We included 476 participants classed as overweight or obese with metabolic syndrome from three centers in Spain. These participants underwent lifestyle assessments and transthoracic echocardiography at baseline and repeated measurements of the Trail Making A test, a measure of executive function, taken at baseline and at the two-year follow-up. We conducted mediation analyses to test if measures of left atrial structure and function mediated associations between adherence to the Mediterranean diet scores, physical activity, and weight at baseline, as well as a two-year change in Trail Making A scores. The analysis did not find an association between these factors and Trail Making A scores, and no indirect effects appeared to be mediated by echocardiographic measurements. The modest sample size in this analysis is a limitation, and larger studies should be conducted to determine potential cardiovascular factors mediating the association between lifestyle and cognition.