Combined serum free light chain levels are associated with carotid atherosclerosis in type 2 diabetes mellitus

Background: Patients with type 2 diabetes mellitus face an increased risk of cardiovascular events compared to non-diabetic counterparts. Chronic inflammation and activation of the immune system, including B-lymphocyte maturation is believed to play a role in atherosclerosis. Recent investigations suggest combined serum free light chains as a potential biomarker for cardiovascular events. The aim of this analysis was to investigate the association of combined serum free light chain with carotid atherosclerosis in subjects with type 2 diabetes mellitus. Methods: We performed a cross-sectional analysis of data from a prospective single centre 2-year study of 97 patients with type 2 diabetes mellitus and insufficiently controlled cardiovascular risk factors. Complete data on combined serum free light chain, high-sensitivity C-reactive protein were available for 75 subjects. Results: We analysed data of 26 female and 49 male subjects, aged 59 ± 8 years. Their mean body mass index was 31.6 ± 4.4 kg/m², and the median B-score was 2 (interquartile range: 0–3). Significant positive correlations between combined serum free light chain and the B-score (r = 0.38; p = 0.001) as well as combined serum free light chain and high-sensitivity C-reactive protein (r = 0.35; p = 0.002) were observed. The adjusted odds ratio for a half standard deviation increase in combined serum free light chain was 1.48 (95% confidence interval: 1.05–2.05) in an ordinal regression model for carotid B-score. Conclusion: In our study, combined serum free light chain was associated with carotid atherosclerosis in subjects with type 2 diabetes mellitus.