Effects of age, sex, and anthropometric factors on nerve conduction measures

Associations among measures of median, ulnar, and sural nerve conduction and age, skin temperature, sex, and anthropometric factors were evaluated in a population of 105 healthy, asymptomatic adults without occupational exposure to highly repetitive or forceful hand exertions. Height was negatively associated with sensory amplitude in all nerves tested (P less than 0.001), and positively associated with median and ulnar sensory distal latencies (P less than 0.01) and sural latency (P less than 0.001). Index finger circumference was negatively associated with median and ulnar sensory amplitudes (P less than 0.05). Sex, in isolation from highly correlated anthropometric factors such as height, was not found to be a significant predictor of median or ulnar nerve conduction measures. Equations using age, height, and finger circumference for prediction of normal values are presented. Failure to adjust normal nerve conduction values for these factors decreases the diagnostic specificity and sensitivity of the described measures, and may result in misclassification of individuals.