RESUMEN
BACKGROUND: As life expectancy is increasing and healthy ageing becomes more and more important, skin ageing is a growing topic of interest from both a medical and a commercial point of view. The urgency to unravel the causes of skin ageing is rising. However, there is a lack of objective, simple, noninvasive methods to assess biological skin age - a term introduced to describe how old someone looks, covering both the appearance and function of the skin. A rapid, noninvasive assessment of biological skin age would greatly facilitate the execution of the studies required to find the causes of skin ageing. OBJECTIVES: To find an objective, easy-to-apply method to assess biological skin age. METHODS: Skin age score (SAS) was compared with skin autofluorescence, a measure of advanced glycation end products in the skin, and several subject characteristics in 32 healthy, white women with little sun-exposed skin and no history of smoking. RESULTS: A moderate, positive correlation (R(2) = 0·32, P = 0·001) between SAS and skin autofluorescence-based biological skin age was found. However, the variation in biological skin age according to SAS could be explained better by body mass index, chronological age and hormonal status (R(2) = 0·86, P < 0·001). CONCLUSIONS: In the current setting skin autofluorescence did not contribute better to the prediction of biological skin age than chronological age. Biological skin age was best predicted by body mass index, chronological age and hormonal status, and this approach provides a considerable simplification of the application of biological skin age.