Low-grade inflammation in type 2 diabetes: a cross-sectional study from a Danish diabetes outpatient clinic.

Abstract

To investigate low-grade inflammation in type 2 diabetes and explore associations to clinical aspects as well as microvascular and macrovascular complications. Cross-sectional analysis. The outpatient diabetes clinic at the Department of Endocrinology at Aalborg University Hospital, Denmark. 100 participants with type 2 diabetes confirmed by a haemoglobin A1c (HbA1c)≥6.5% for a minimum of 1 year and 21 healthy controls. Serum levels of 27 inflammation-related biomarkers measured by immunoassay. Associations with microvascular and macrovascular complications, body weight, glycaemic control, medication and sex were investigated in the diabetes cohort. Serum levels of tumour necrosis factor (TNF)-α and eotaxin were elevated in type 2 diabetes (p<0.05), while interleukin (IL)-7 was decreased (p<0.001). IL-12/IL-23p40, IL-15, macrophage-derived chemokine (MDC) and C reactive protein (CRP) levels were increased with body weight (p<0.05), while eotaxin and TNF-α were increased with elevated HbA1c levels (p<0.04). Dipeptidyl peptidase-4 inhibitor therapy was associated with lower levels of induced protein-10, MDC and thymus and activation regulated chemokine (p<0.02), while females had higher levels of MDC (p=0.027). Individuals with ≥3 diabetic complications had elevated levels of IL-6, IL-10, IL-12/IL-23p40, IL-15 and CRP compared with those with ≤3 (p<0.05). The level of low-grade inflammation in type 2 diabetes is associated with obesity, glycaemic regulation, therapeutical management, sex and complications. Our results underline the importance of addressing inflammatory issues in type 2 diabetes, as these may predispose for crippling comorbidities.