title: The effects of age, gender, and body mass index on amplitude of sensory nerve action potentials: multivariate analyses.
abstract: OBJECTIVE
  Previous studies have shown that age, gender, and body mass index (BMI) affect amplitude of sensory nerve action potentials (SNAP), but the total effects of multiple factors or the most prominently affected nerves have not been elucidated. This study systematically investigated effects of these factors.
  
  
  METHODS
  Amplitude of SNAP of the median, ulnar, superficial radial, superficial peroneal, and sural nerves was measured in 105 healthy subjects. The effects of age, gender, and BMI on each nerve were estimated by multivariate linear regression analysis.
  
  
  RESULTS
  SNAP amplitude decreased with age in all five nerves. Women had greater SNAP amplitude than men in the upper limb nerves (median, ulnar, and radial), but not in the lower limb nerves (peroneal and sural). Similarly, greater BMI was associated with smaller amplitudes in the upper limb nerves, but not in the lower limb nerves. Multivariate analyses showed the three factors explained 50% of the variation in the median nerve, 46% in the ulnar nerve, and 22-32% in the remaining nerves.
  
  
  CONCLUSIONS
  The effects of age, gender, and BMI on SNAP amplitudes are not identical in different sensory nerves. Age was strongly correlated with SNAP amplitude in the nerves tested, whereas gender and BMI affect amplitudes only in the upper limb nerves.
  
  
  CONCLUSIONS
  Age, gender, and BMI should be taken into account in clinical practice, but the extent of influence depends on the sensory nerves examined.
authors.affiliation: Department of Neurology, Graduate School of Medicine, Chiba University, 1-8-1, Inohana, Chuo-ku, Chiba, Japan.
authors.forename: Yumi
authors.initials: Y
authors.lastname: Fujimaki
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kuwabara
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Sato
authors.forename: Sagiri
authors.initials: S
authors.lastname: Isose
authors.forename: Kazumoto
authors.initials: K
authors.lastname: Shibuya
authors.forename: Yukari
authors.initials: Y
authors.lastname: Sekiguchi
authors.forename: Saiko
authors.initials: S
authors.lastname: Nasu
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Noto
authors.forename: Junko
authors.initials: J
authors.lastname: Taniguchi
authors.forename: Sonoko
authors.initials: S
authors.lastname: Misawa
mesh_terms: D000200:Action Potentials / Q000502:physiology*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D015992:Body Mass Index; D004594:Electrophysiology; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009431:Neural Conduction / Q000502:physiology; D010525:Peripheral Nerves / Q000502:physiology; D011984:Sensory Receptor Cells / Q000502:physiology*; D012727:Sex Characteristics; D055815:Young Adult