title: Peripheral nerve function and lower extremity muscle power in older men.
abstract: OBJECTIVE
  To assess whether sensorimotor peripheral nerve function is associated with muscle power in community-dwelling older men.
  
  
  METHODS
  Longitudinal cohort study with 2.3±0.3 years of follow-up.
  
  
  METHODS
  One clinical site.
  
  
  METHODS
  Participants (n=372; mean age ± SD, 77.2±5.1y; 99.5% white; body mass index, 27.9±3.7kg/m(2); power, 1.88±0.6W/kg) at 1 site of the Osteoporotic Fractures in Men Study (N=5994).
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  A nerve function ancillary study was performed 4.6±0.4 years after baseline. Muscle power was measured using a power rig. Peroneal motor nerve conduction amplitude, distal motor latency, and mean f-wave latency were measured. Sensory nerve function was assessed using 10-g and 1.4-g monofilaments and sural sensory nerve conduction amplitude and distal latency. Peripheral neuropathy symptoms at the leg and feet were assessed by self-report.
  
  
  RESULTS
  After adjustments for age, height, and total body lean and fat mass, 1 SD lower motor (β=-.07, P<.05) and sensory amplitude (β=-.09, P<.05) and 1.4-g (β=-.11, P<.05) and 10-g monofilament insensitivity (β=-.17, P<.05) were associated with lower muscle power/kg. Compared with the effect of age on muscle power (β per year, -.05; P<.001), this was equivalent to aging 1.4 years for motor amplitude, 1.8 years for sensory amplitude, 2.2 years for 1.4-g monofilament detection, and 3.4 years for 10-g detection. Baseline 1.4-g monofilament detection predicted a greater decline in muscle power/kg. Short-term change in nerve function was not associated with concurrent short-term change in muscle power/kg.
  
  
  CONCLUSIONS
  Worse sensory and motor nerve function were associated with lower muscle power/kg and are likely important for impaired muscle function in older men. Monofilament sensitivity was associated with a greater decline in muscle power/kg, and screening may identify an early risk for muscle function decline in late life, which has implications for disability.
authors.affiliation: Department of Epidemiology, University of Pittsburgh, Pittsburgh, PA.
authors.forename: Rachel E
authors.initials: RE
authors.lastname: Ward
authors.affiliation: Institute of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark.
authors.forename: Paolo
authors.initials: P
authors.lastname: Caserotti
authors.affiliation: National Institute for Occupational Safety and Health (NIOSH), National Personal Protective Technology Laboratory, Pittsburgh, PA.
authors.forename: Kimberly
authors.initials: K
authors.lastname: Faulkner
authors.affiliation: Department of Epidemiology, University of Pittsburgh, Pittsburgh, PA.
authors.forename: Robert M
authors.initials: RM
authors.lastname: Boudreau
authors.affiliation: VA Pittsburgh HCS and Department of Neurology, University of Pittsburgh, Pittsburgh, PA.
authors.forename: Sasa
authors.initials: S
authors.lastname: Zivkovic
authors.affiliation: Research Service, Department of Veterans Affairs Medical Center, Portland, OR.
authors.forename: Christine
authors.initials: C
authors.lastname: Lee
authors.affiliation: Sanford Burnham Medical Research Institute, Orlando, FL.
authors.forename: Bret H
authors.initials: BH
authors.lastname: Goodpaster
authors.affiliation: California Pacific Medical Center Research Institute, San Francisco, CA.
authors.forename: Peggy M
authors.initials: PM
authors.lastname: Cawthon
authors.affiliation: Department of Epidemiology, University of Pittsburgh, Pittsburgh, PA.
authors.forename: Anne B
authors.initials: AB
authors.lastname: Newman
authors.affiliation: Department of Epidemiology, University of Pittsburgh, Pittsburgh, PA.
authors.forename: Jane A
authors.initials: JA
authors.lastname: Cauley
authors.affiliation: Department of Epidemiology, University of Pittsburgh, Pittsburgh, PA. Electronic address: StrotmeyerE@edc.pitt.edu.
authors.forename: Elsa S
authors.initials: ES
authors.lastname: Strotmeyer
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology; D015331:Cohort Studies; D006801:Humans; D016014:Linear Models; D008137:Longitudinal Studies; D035002:Lower Extremity / Q000294:innervation / Q000502:physiology*; D008297:Male; D053580:Muscle Strength / Q000502:physiology*; D009431:Neural Conduction / Q000502:physiology*; D010543:Peroneal Nerve / Q000502:physiology*; D013497:Sural Nerve / Q000502:physiology*
keywords: Aged; Motor neurons; Muscle weakness; Peripheral nerves; Rehabilitation; Sensory function; Sensory neurons