Sensory and motor peripheral nerve function and lower-extremity quadriceps strength: the health, aging and body composition study.
OBJECTIVE
To determine whether sensory and motor nerve function is associated cross-sectionally with quadriceps or ankle dorsiflexion strength in an older community-based population.


METHODS
Cross-sectional analyses within a longitudinal cohort study.


METHODS
Two U.S. clinical sites.


METHODS
Two thousand fifty-nine Health, Aging and Body Composition Study (Health ABC) participants (49.5% male, 36.7% black, aged 73-82) in 2000/01.


METHODS
Quadriceps and ankle strength were measured using an isokinetic dynamometer. Sensory and motor peripheral nerve function in the legs and feet was assessed using 10-g and 1.4-g monofilaments, vibration threshold, and peroneal motor nerve conduction amplitude and velocity.


RESULTS
Monofilament insensitivity, poorest vibration threshold quartile (>60 mu), and poorest motor nerve conduction amplitude quartile (<1.7 mV) were associated with 11%, 7%, and 8% lower quadriceps strength (all P<.01), respectively, than in the best peripheral nerve function categories in adjusted linear regression models. Monofilament insensitivity and lowest amplitude quartile were both associated with 17% lower ankle strength (P<.01). Multivariate analyses were adjusted for demographic characteristics, diabetes mellitus, body composition, lifestyle factors, and chronic health conditions and included all peripheral nerve measures in the same model. Monofilament insensitivity (beta=-7.19), vibration threshold (beta=-0.097), and motor nerve conduction amplitude (beta=2.01) each contributed independently to lower quadriceps strength (all P<.01). Monofilament insensitivity (beta=-5.29) and amplitude (beta=1.17) each contributed independently to lower ankle strength (all P<.01). Neither diabetes mellitus status nor lean mass explained the associations between peripheral nerve function and strength.


CONCLUSIONS
Reduced sensory and motor peripheral nerve function is related to poorer lower extremity strength in older adults, suggesting a mechanism for the relationship with lower extremity disability.
Strotmeyer
Elsa S
ES
Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA. StrotmeyerE@edc.pitt.edu
de Rekeneire
Nathalie
N
Schwartz
Ann V
AV
Resnick
Helaine E
HE
Goodpaster
Bret H
BH
Faulkner
Kimberly A
KA
Shorr
Ronald I
RI
Vinik
Aaron I
AI
Harris
Tamara B
TB
Newman
Anne B
AB
D000203:Activities of Daily Living / Q000145:classification; D000368:Aged; D000375:Aging / Q000502:physiology*; D001823:Body Composition / Q000502:physiology*; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D003929:Diabetic Neuropathies / Q000175:diagnosis / Q000503:physiopathology; D005260:Female; D015577:Geriatric Assessment; D006801:Humans; D007866:Leg / Q000294:innervation*; D008297:Male; D009046:Motor Neurons / Q000502:physiology*; D053580:Muscle Strength / Q000502:physiology*; D009460:Neurologic Examination; D010525:Peripheral Nerves / Q000502:physiology*; D011446:Prospective Studies; D052097:Quadriceps Muscle / Q000294:innervation; D012016:Reference Values; D011984:Sensory Receptor Cells / Q000502:physiology*; D012684:Sensory Thresholds / Q000502:physiology; D014481:United States; D014732:Vibration