Determinants of epidermal nerve fiber density in normal individuals.
We studied the relationship between epidermal innervation and age, gender, height, and weight. Intraepidermal nerve fiber density (IENFD) of skin biopsies obtained from the proximal thigh and ankle of 84 normal individuals was quantified. A linear regression model was performed using IENFD at the thigh, IENFD at the ankle, and the thigh IENFD/ankle IENFD ratio, with age, gender, and height-weight interaction as predictors. An independent, negative correlation was found between age and IENFD at the ankle. No correlation was found between age and IENFD at the thigh. With increasing age the thigh IENFD/ankle IENFD ratio, a measure of the length-dependent distal-to-proximal gradient of epidermal nerve density, increased significantly. Gender, height, and body weight did not independently influence IENFD at either site. In normal individuals, distal epidermal innervation decreases in a length-dependent manner with advancing age. This must be considered when interpreting IENFD in disease states.
Umapathi
T
T
National Neuroscience Institute, 11 Jalan Tan Tock Seng, 308433 Singapore. umapathi@nni.com.sg
Tan
Wan Loo
WL
Tan
Nigel C K
NC
Chan
Yiong Huak
YH
D000328:Adult; D000367:Age Factors; D000368:Aged; D001827:Body Height; D001835:Body Weight; D002452:Cell Count / Q000592:standards* / Q000706:statistics & numerical data; D004817:Epidermis / Q000294:innervation*; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009412:Nerve Fibers; D017933:Peripheral Nervous System / Q000166:cytology*; D012016:Reference Values; D012737:Sex Factors