Reference ranges of skin micro-relief according to age in French Caucasian and Japanese women.

Background/purpose: The variation of skin surface morphological indicators according to age has not been frequently studied. The aim of this work was to establish French Caucasian and Japanese reference ranges of these indicators according to age. Methods: Two studies were performed simultaneously in Paris and Sendai on 356 Caucasian and 120 Japanese healthy women aged from 20 to 80 years. Skin replicas were obtained from the volar forearm and analysed by interferometry. This analysis yielded 16 morphological indicators. Reference ranges according to age were established using the statistical methodology defined by Royston. Results/discussion: Reference ranges were found for 15 out of the 16 parameters for the French women as well as for the Japanese women. The models' truthfulness will have to be confirmed using new samples, larger if possible. Moreover, non-parametric methods will be used in order to compare the results provided by these approaches.