Correlation Between Advanced Glycation End Products and Ultrasonographic Measurements of Cervico-Facial Skin Tissue

Background/Objectives: Advanced glycation end products (AGEs) accumulate in long-lived extracellular matrix proteins and have been implicated in skin aging and tissue remodeling, particularly in photo-exposed skin. High-frequency ultrasound (HFU) offers a non-invasive assessment of structural skin parameters that may reflect these changes. This study aimed to explore the associations between serum AGEs and HFU-derived structural parameters of cervico-facial skin, with a focus on UV-exposed dermal tissue. Methods: This cross-sectional study included 113 adults recruited in Cluj-Napoca, Romania. Fasting serum samples were analyzed for fructosyl-lysine (FruLys), pyrraline (Pyr), methylglyoxal-derived hydroimidazolone-1 (MG-H1), carboxyethyl-lysine (CEL), carboxymethyl-lysine (CML), arginine (Arg), and lysine (Lys). HFU, using a 22 MHz probe, was performed on the left zygomatic area to assess epidermal depth and density, UV-exposed dermal damage depth and density, dermis depth and density, and subcutaneous tissue depth and density. Associations between serum AGEs and HFU parameters were evaluated using Spearman correlation, with Benjamini-Hochberg false discovery rate (FDR) correction for multiple testing. Results: After FDR correction, epidermal depth was inversely correlated with serum CML (r = -0.402, adjusted p = 0.018). UV-exposed dermal density was inversely correlated with serum Pyr (r = -0.547, adjusted p < 0.019), Arg (r = -0.369, adjusted p < 0.019), and Lys (r = -0.270, adjusted p < 0.019). Subcutaneous tissue depth was also inversely correlated with serum CML (r = -0.290, adjusted p = 0.020). Conclusions: The study showed that higher levels of specific serum AGEs were associated with selected HFU-derived structural alterations in cervico-facial skin, particularly in UV-exposed dermal tissue. These exploratory findings support the biological plausibility that systemic glycation may be reflected by non-invasive skin ultrasound parameters.