Developmental and sex differences in somatosensory perception--a systematic comparison of 7- versus 14-year-olds...

There are controversial discussions regarding developmental- and sex-related differences in somatosensory perception, which were found, eg, when comparing younger children (6-8 years), older children (9-12 years), and adolescents (13-16 years) using quantitative sensory testing (QST). The aim of our current study was to systematically assess the impact of age and sex using the QST protocol of the German Research Network on Neuropathic Pain (DFNS). QST, including thermal and mechanical detection and pain thresholds, was assessed in 86 healthy 7-year-old children (42 girls and 44 boys) and 87 healthy 14-year-old adolescents (43 girls and 44 boys). The sample size was calculated a priori to detect medium-sized effects as found in the previous studies with adequate power. Developmental and sex differences were tested using univariate analysis of variance. Children were more sensitive to most pain stimuli, except cold pain stimuli, compared with adolescents, but did not differ in mechanical and thermal detection thresholds except in regard to cold stimuli. Sex had an impact only on warm detection, with girls being more sensitive. There were no interactions between age and sex. In conclusion, developmental changes during the puberty appear to influence pain perception, whereas sex effects in childhood are negligible. At present, it is not clear what brings about the differences between adult men and women that are apparent in epidemiological studies. Our results contradict the hypothesis that differences in peripheral nerve-fiber functioning underlie sex effects.