title: Reduced heart rate variability is associated with worse cognitive performance in elderly Mexican Americans.
abstract: Reduced heart rate variability is a strong predictor of cardiovascular risk factors, cardiovascular events, and mortality and thus may be associated with cognitive neurodegeneration. Yet, this has been relatively unexplored, particularly in minority populations with high cardiovascular burden. We used data from the Sacramento Area Latino Study on Aging to examine the cross-sectional association of reduced heart rate variability with cognitive function among elderly Mexican Americans. A total of 869 participants (mean age, 75 years; 59% women) had their 6-minute heart rate variability measured using an ECG monitor and respiration pacer in response to deep breathing. We used the mean circular resultant, known as R bar, as a measure of heart rate variability and categorized it into quartiles (Q1 to Q4 of R bar: reduced to high heart rate variability). Cognitive function was assessed using the modified Mini-Mental State Examination, a 100-point test of global cognitive function, and the Spanish and English verbal learning test, a 15-point test of verbal memory recall. In fully adjusted linear regression models, participants in quartile 1 had a 4-point lower modified Mini-Mental State Examination score (P<0.01), those in quartile 2 had a 2-point lower score (P=0.04), and those in quartile 3 had a 1-point lower score (P=0.35) compared with those in the highest quartile of R bar. Reduced R bar was not associated with verbal memory. Our results suggest that reduced heart rate variability is associated with worse performance on the test of global cognitive function, above and beyond traditional cardiovascular risk factors.
authors.affiliation: Department of Epidemiology and Biostatistics, School of Medicine, University of California San Francisco, 185 Berry St, Lobby 5, Suite 5700, San Francisco, CA 94107. Adina.zekialhazzouri@ucsf.edu.
authors.forename: Adina
authors.initials: A
authors.lastname: Zeki Al Hazzouri
authors.forename: Mary N
authors.initials: MN
authors.lastname: Haan
authors.forename: Yingzi
authors.initials: Y
authors.lastname: Deng
authors.forename: John
authors.initials: J
authors.lastname: Neuhaus
authors.forename: Kristine
authors.initials: K
authors.lastname: Yaffe
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003071:Cognition / Q000502:physiology*; D003072:Cognition Disorders / Q000503:physiopathology*; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D017058:Mexican Americans; D008875:Middle Aged; D012307:Risk Factors
keywords: aging; autonomic nervous system diseases; cognition; epidemiology