Association between serum values of C-reactive protein and cytokine production in whole blood of patients with Type 2 diabetes

Abstract

Diabetes mellitus accelerates atherosclerotic processes, and it is known that inflammation plays a key role in atherosclerosis. The aim of the present study was to evaluate in patients with Type 2 diabetes whether serum levels of CRP (C-reactive protein) are associated with cytokine production in whole blood. A total of 89 outpatients with Type 2 diabetes were enrolled, and blood pressure, body mass index, fasting blood glucose, glycated haemoglobin, cholesterol, triacylglycerols (triglycerides) and hs-CRP (high-sensitivity CRP) were measured. IL-6 (interleukin-6), IL-1β (interleukin-1β) and TNF-α (tumour necrosis factor-α) were measured before and after 24 h of incubation of whole blood with LPS (lipopolysaccharide) or saline. The basal values of IL-1β, IL-6 and TNF-α were low and were not significantly related to hs-CRP levels. A univariate analysis showed that the level of IL-1β and IL-6, obtained after 24 h of incubation of whole blood with LPS, increased significantly with increasing levels of hs-CRP and, after adjusting for potential confounders, IL-1β still remained statistically significant. In our sample of patients with Type 2 diabetes, there was no association between serum hs-CRP levels and basal levels of IL-6, IL-1β and TNF-α. Conversely, a significant association was observed between serum hs-CRP levels and IL-1β and IL-6 production after 24 h of incubation of whole blood with LPS. In conclusion, our data suggest that patients with Type 2 diabetes and high hs-CRP levels may have an enhanced reactivity in response to specific stimuli that produce different interleukins, with possible implications in inflammatory atherosclerotic processes.