Ethnic and gender differences in advanced glycation end products measured by skin auto-fluorescence

Background: Advanced glycation end products (AGEs) have been shown to be a predictor of cardiovascular risk in Caucasian subjects. In this study we examine whether the existing reference values are useable for non-Caucasian ethnicities. Furthermore, we assessed whether gender and smoking affect AGEs. Methods: AGEs were determined by a non-invasive method of skin auto-fluorescence (AF). AF was measured in 200 Arabs, 99 South Asians, 35 Filipinos and 14 subjects of other/mixed ethnicity in the Qatar Metabolomics Study on Diabetes (QMDiab). Using multivariate linear regression analysis and adjusting for age and type 2 diabetes, we assessed whether ethnicity, gender and smoking were associated with AF. Results: The mean AF was 2.27 arbitrary units (AU) (SD: 0.63). Arabs and Filipinos had a significant higher AF than the South Asian population (0.25 arbitrary units (AU) (95% CI: 0.11-0.39), p = 0.001 and 0.34 (95% CI: 0.13-0.55), p = 0.001 respectively). Also, AF was significantly higher in females (0.41 AU (95% CI: 0.29-0.53), p < 0.001). AF associated with smoking (0.21 AU (95% CI: 0.01-0.41), p = 0.04) and increased with the number of pack-years smoked (p = 0.02). Conclusions: This study suggests that the existing reference values should take ethnicity, gender and smoking into account. Larger studies in specific ethnicities are necessary to create ethnic-and gender-specific reference values.