Autofluorescence of Human Skin is Age-Related After Correction for Skin Pigmentation and Redness

Abstract

When measuring the skin fluorescence in vivo, the absorption of chromophores such as melanin and hemoglobin often contribute predominantly to the changes in fluorescence and obscure the information from the fluorophores. We measured in vivo the collagen-linked 375 nm fluorescence (excitation: 330 nm) and 455 nm fluorescence (excitation: 370 nm) from nonexposed buttock skin of healthy volunteers. Skin pigmentation and redness of the same sites were quantified by reflectance of the skin at 555 nm and 660 nm. Multiple regression analysis was used to find the correlation between the fluorescence and skin pigmentation and redness. The fluorescence was corrected for the impact of pigmentation and redness according to the equation found in the regression analyses. The age-related trend of the fluorescence was evaluated. The 375 nm fluorescence showed positive relation to age, whereas the 455 nm fluorescence showed no significant relation to age. The increasing rate of the 375 nm fluorescence (logarithm transformed) was 2% per year, which is comparable with previously published data. The results suggest that the correction of the autofluorescence intensity for skin pigmentation and redness is valid, and the 375 nm skin autofluorescence may be used as a biologic marker of skin aging in vivo.

Simple non-invasive assessment of advanced glycation endproduct accumulation

“…Because skin pigmentation may absorb light and thus influence autofluorescence, skin reflection measurements across the 300-to 420-nm range were compared with those of a white Teflon block (assuming 100% reflectance) [27]. Skin reflection was calculated by dividing the mean intensity of light reflected from the skin by the mean intensity reflected from the white Teflon block across the 300-to 420-nm range.…”

Skin Autofluorescence as a Noninvasive Marker of Vascular Damage in Patients With Type 2 Diabetes

“…Second, other fluorophores might be measured (e.g., NADH, which has an overlapping excitation spectrum [350 -370 nm]) (16). Finally, the large majority of our study population was Caucasian.…”

In vivospectrofluorimetry reveals endogenous biomarkers that report healthspan and dietary restriction inCaenorhabditis elegans

“…In vivo fluorescence spectroscopy has been previously used on humans and other mammals to measure endogenous autofluorescent species of skin and other tissues (Leffell et al 1988;Kollias et al 1998;Brancaleon et al 1999;Gillies et al ., 2000;Doukas et al ., 2001;Na et al ., 2001;Sandby-Moller et al ., 2003). Fluorescent species that are common in many biological tissues include the aromatic amino acids (tryptophan, tyrosine and phenylalanine), cross-linked collagen and elastin, lipofuscin, NADH, and FAD.…”