Skin- and Plasmaautofluorescence in hemodialysis with glucose-free or glucose-containing dialysate

Abstract Background Haemodialysis (HD) patients suffer from an increased risk of cardiovascular disease (CVD). Skin autofluorescence (SAF) is a strong marker for CVD. SAF indirectly measures tissue advanced glycation end products (AGE) being cumulative metabolites of oxidative stress and cytokine-driven inflammatory reactions. The dialysates often contain glucose. Methods Autofluorescence of skin and plasma (PAF) were measured in patients on HD during standard treatment (ST) with a glucose-containing dialysate ( n \u2009=\u200924). After that the patients were switched to a glucose-free dialysate (GFD) for a 2-week period. New measurements were performed on PAF and SAF after 1\ua0week (M1) and 2\ua0weeks (M2) using GFD. Nonparametric paired statistical analyses were performed between each two periods. Results SAF after HD increased non-significantly by 1.2% while when a GFD was used during HD at M1, a decrease of SAF by 5.2% ( p \u2009=\u20090.002) was found. One week later (M2) the reduction of 1.6% after the HD was not significant ( p \u2009=\u20090.33). PAF was significantly reduced during all HD sessions. Free and protein-bound PAF decreased similarly whether glucose containing or GFD was used. The HD resulted in a reduction of the total PAF of approximately 15%, the free compound of 20% and the protein bound of 10%. The protein bound part of PAF corresponded to approximately 56% of the total reduction. The protein bound concentrations after each HD showed the lowest value after 2\ua0weeks using glucose-free dialysate ( p \u2009<\u20090.05). The change in SAF could not be related to a change in PAF. Conclusions When changing to a GFD, SAF was reduced by HD indicating that such measure may hamper the accumulation and progression of deposits of AGEs to protein in tissue, and thereby also the development of CVD. Glucose-free dialysate needs further attention. Protein binding seems firm but not irreversible. Trial registration ISRCTN registry: ISRCTN13837553 . Registered 16/11/2016 (retrospectively registered)

Skin color independent assessment of aging using skin autofluorescence

Skin autofluorescence (AF) for the non-invasive assessment of the amount of accumulated tissue Advanced Glycation Endproducts (AGEs) increases with aging. In subjects with darker skin colors, measurements typically result in lower AF values than in subjects with fair skin colors, e.g. due to selective absorption by skin compounds. Our aim was to provide a new method for calculating skin AF, yielding values that are independent of skin color. The deviation of skin AF of healthy subjects with various darker skin types (N = 99) compared to reference values from Caucasians showed to be a function of various parameters that were derived from reflectance and emission spectra in the UV and visible range (adjusted R(2) = 80%). Validation of the new algorithm, based on these findings, in a separate dataset (N = 141) showed that results of skin AF can now be obtained to assess skin AGEs independently of skin colo