Skin auto-fluorescence as a measure of advanced glycation end-products is associated with microvascular health in patients with COPD

Background and objectives: Chronic obstructive pulmonary disease (COPD) is associated with systemic inflammation and oxidative stress. These physiological processes can lead to increased formation and accumulation of advanced glycation end-products (AGEs), that can play a role in vascular complications. In this crosssectional study, we determined the association between skin AGEs and microvascular health in patients with COPD.Methods: Clinical characteristics and cardiovascular parameters, including pulmonary function, metabolic and inflammatory parameters, and blood pressure, were obtained in this observational study with patients with COPD. Skin concentrations of AGEs were assessed non-invasively by measuring skin autofluorescence (AF). Retinal vessel analysis was used as a marker of microvascular health.Results: 62 patients with COPD (52% males; mean age: 64.4 +/- 8.4 years; mean FEV1: 45.0 +/- 20.7%pred.) were analysed. Mean skin AF was 2.75 +/- 0.64 arbitrary units. Skin AF in patients with COPD was negatively associated with retinal arteriolar diameter (beta -0.021, 95% CI -0.040 to -0.002; p = 0.031) and arteriole-to-venular ratio (beta -7.233, 95% CI -9.732 to -4.734; p <0.001) and positively associated with retinal venular diameter (beta 0.029, 95% CI 0.019 to 0.038; p <0.001) after adjustment for sex, age, lung function, pack-years of smoking and conventional cardiovascular risk factors.Conclusion: We document for the first time that skin AF in patients with COPD is independently associated with retinal arteriolar and venular vessel diameters, biological indicators for microvascular health. This adds to the evidence that AGEs are an accessible marker of microvascular health.