Assessment of the usefulness of skin autofluorescence as an indicator of disease activity and of the risk of developing diabetes in patients suffering from rheumatoid arthritis

OBJECTIVES Diabetes develops much more often in patients suffering from rheumatoid arthritis (RA) than in healthy population. One of the parameters which allow to evaluate the risk of developing diabetes and cardiovascular diseases (CVD) is the level of advanced glycation end products (AGE) in the skin. In patients suffering from RA, an increase in AGE level may be also linked with the course of the underlying disease. The aim of the study was to evaluate the correlation between the AGE level and the course of RA as well as other risk factors for the development of diabetes and CVD. MATERIAL AND METHODS The study included 148 patients divided into three groups: group I - patients with RA (n = 102, 79 F/23 M), group II - patients with RA and diabetes (n = 21, 14 F/7 M), group III - healthy individuals (n = 25, 16 F/9 M). Each patient underwent a skin autofluorescence signal (SAF) examination with an AGE Reader, which allows the assessment of AGE level, as well as being subjected to the laboratory tests panel. Additionally, patients from group I and II have had their DAS28 (ESR) indicator calculated. RESULTS In groups I, II, and III, the respective mean SAF values, expressed in arbitrary units [au], were to 2.54, 2.74, and 1.96 au. Between-group differences in terms of mean SAF values were statistically significant (p < 0.05). CONCLUSIONS Significantly higher mean SAF values in groups I and II as compared to group III suggest that the increase in the AGE level in patients with RA is linked with the underlying disease and does not have to correspond with the real risk of diabetes and CVD. In conclusion, despite the known limitations of the technique, measuring AGE levels allows for closer monitoring of RA patients who are at a higher risk of developing diabetes.