Abstract
Low-grade inflammation is a major player in obesity and the metabolic syndrome predicting development of type 2 diabetes (T2DM). The interleukin-1 receptor antagonist (IL-1Ra) is a vital and natural anti-inflammatory factor and mediator in glucose homeostasis disturbances. The predictive role is independent of multiple confounders, and elevated levels appear few years before T2DM. The role of IL-1Ra is important for accumulated risk factors, dysregulated metabolism and glucose homeostasis, and dietary interventions. Longitudinal and cross-sectional population study cohorts have enabled the approximation of IL-1Ra limit values for metabolic dysregulation and guide further analysis as a potential biomarker. The limit value of IL-1Ra is reaching 400 pg/mL with prediabetes and before T2DM. However, subjects with metabolic syndrome are suggested to have lower limit values, especially among men. Future research may evaluate the role of IL-1Ra in actual glucose homeostasis together with routine fasted laboratory tests, such as glucose and C-reactive protein (CRP) instead of the oral glucose tolerance test. The significance of intermediate low IL-1Ra levels in metabolic abnormalities should be further analyzed. It is possible to specify the impact of multiple lifestyle and metabolic parameters together with age and sex. IL-1Ra could be studied in multiple approaches including interventional studies of metabolic diseases.