Obesity and cognitive dysfunction in heart failure: the role of hypertension, type 2 diabetes, and physical fitness.
BACKGROUND
Cognitive impairment is common in heart failure. Obesity is a known risk factor for cognitive dysfunction in heart failure, though the mechanisms remain unclear. Obesity increases risk for conditions like hypertension and type 2 diabetes mellitus (T2DM) as well as poor fitness levels, and this may serve as one possible pathway accounting for association between obesity and cognitive dysfunction.


OBJECTIVE
We used structural equation modeling to test whether the combination of hypertension, T2DM, and reduced fitness mediate the association between obesity and cognitive dysfunction.


METHODS
Two hundred heart failure patients completed neuropsychological testing and a physical fitness assessment. Hypertension and T2DM were ascertained via self-report and medical records. Body mass index (BMI) was calculated.


RESULTS
Forty-three percent of the sample was obese. Hypertension (70%) and T2DM (36%) were common, and fitness levels were reduced. The structural equation model with these factors as mediators between BMI and cognitive function demonstrated excellent fit (comparative fit index = 0.98; root mean-square error of approximations = 0.03). Higher BMI correlated with hypertension, T2DM, and poorer fitness. Each of these factors predicted worse cognition. Models that isolated medical comorbidities and physical fitness as the mediator were weaker than the full model.


CONCLUSIONS
Increased risk for medical comorbidities and reduced fitness levels helped to explain the negative effects of obesity on cognitive dysfunction in heart failure. Prospective studies should confirm this pattern and examine how weight loss benefits cognitive function in heart failure.
Department of Psychology, Kent State University, USA.
Michael L
ML
Alosco
Department of Psychology, Kent State University, USA Department of Psychiatry, Summa Health System, Akron City Hospital, USA.
Mary Beth
MB
Spitznagel
Departments of Neurology Psychiatry and the Institute on Aging, Center for Cognitive Aging and Memory, University of Florida, Gainesville, USA.
Ronald
R
Cohen
Department of Psychology, University of Georgia, Athens, USA.
Lawrence H
LH
Sweet
University Hospitals Case Medical Center and Department of Medicine, Cleveland, USA Harrington Heart and Vascular Institute, Cleveland, USA Case Western Reserve University School of Medicine, Cleveland, USA.
Richard
R
Josephson
Department of Psychology, Kent State University, USA Department of Psychiatry, Summa Health System, Akron City Hospital, USA.
Joel
J
Hughes
Department of Psychiatry, Summa Health System, Akron City Hospital, USA.
Jim
J
Rosneck
Department of Psychology, Kent State University, USA jgunstad@kent.edu.
John
J
Gunstad
D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D003072:Cognition Disorders / Q000209:etiology*; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000523:psychology*; D005260:Female; D006333:Heart Failure / Q000150:complications / Q000523:psychology*; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000523:psychology*; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D009765:Obesity / Q000150:complications / Q000523:psychology*; D010809:Physical Fitness; D012307:Risk Factors
Physical fitness; cognitive function; heart failure; hypertension; obesity; type 2 diabetes mellitus