Multisystem physiologic impairments and changes in gait speed of older adults.
BACKGROUND
Slowed gait is an important health indicator in older adults but a single identifiable cause is often lacking. We assessed whether a summary index measuring impairments across multiple physiologic systems was associated with slowed gait in older individuals.


METHODS
Data from the Cardiovascular Health Study (n = 3,010) were used to assess associations between baseline physiologic index (measuring vasculature, brain, kidneys, lungs, and glucose metabolism; range 0-10 with 0-2 points/system and lower score indicating higher function) and annual gait speed (m/s) over 6 years. Participants with complete data on the physiologic index and at least two gait speed measures were included. Mean gait speed and 95% confidence intervals (CI) by category of index were calculated using mixed effects models.


RESULTS
Those with scores of three or higher on the index had significantly slower gait speed at baseline compared to those with scores of 0-2 (7-10: mean speed = 0.83 m/s, 95% CI: 0.80, 0.84; 0-2: mean speed = 1.01 m/s, 95% CI: 0.99, 1.03). Those with higher indices also had faster decline in gait speed compared to those with lower scores after adjustment for demographic and health characteristics (7-10: change in speed = -0.020 m/s/year, 95% CI: -0.024, -0.016; 0-2: change in speed= -0.010 m/s/year, 95% CI: -0.014, -0.006).


CONCLUSIONS
Greater impairment across five organ systems was associated with slower gait speed and greater declines in gait speed over 6 years. Impairments accumulated over multiple physiologic systems may make older adults more vulnerable to slow gait speed.
Department of Epidemiology, School of Public Health, University of Pittsburgh, Pennsylvania. alr143@pitt.edu.
Andrea L
AL
Rosso
Harvard Affiliated Emergency Medicine Residency, Massachusetts General Hospital & Brigham and Women's Hospital, Massachusetts.
Jason L
JL
Sanders
Department of Biostatistics, School of Public Health, University of Washington, Seattle.
Alice M
AM
Arnold
Department of Epidemiology, School of Public Health, University of Pittsburgh, Pennsylvania.
Robert M
RM
Boudreau
Division of General Medicine, University of California, Davis Medical Center, Sacramento.
Calvin H
CH
Hirsch
Department of Mental Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland.
Michelle C
MC
Carlson
Department of Epidemiology, School of Public Health, University of Pittsburgh, Pennsylvania.
Caterina
C
Rosano
The Sticht Center on Aging and Department of Internal Medicine, Wake Forest School of Medicine, Winston Salem, North Carolina.
Stephen B
SB
Kritchevsky
Department of Epidemiology, School of Public Health, University of Pittsburgh, Pennsylvania.
Anne B
AB
Newman
D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000502:physiology; D002320:Cardiovascular Physiological Phenomena; D015331:Cohort Studies; D005260:Female; D005684:Gait / Q000502:physiology*; D015577:Geriatric Assessment; D005947:Glucose / Q000378:metabolism; D006305:Health Status Indicators; D006801:Humans; D007668:Kidney / Q000502:physiology; D008168:Lung / Q000502:physiology; D008297:Male; D012680:Sensitivity and Specificity; D013997:Time Factors
D005947:Glucose
Epidemiology.; Gait; Physical function