Inflammageing mediated by cytotoxic lymphocytes is associated with diabetes duration.

Aims: Inflammageing, the age-related systemic increase of proinflammatory factors, has been linked to the development of cardiovascular disease, chronic kidney disease and cancer in the elderly. Chronic inflammation is believed to be a causative factor in the development of diabetic complications. However, exactly how type 2 diabetes impacts the inflammatory state of the immune system is incompletely characterised.

Methods: Blood collection and anthropometric measurements were performed in patients with type 2 diabetes (n = 49) and control subjects (n = 30). The phenotype, proliferation capacity and cytokine production by cytotoxic lymphocytes were analysed using multiparametric flow cytometry.

Results: Type 2 diabetes did not impact the phenotype or proliferation of the investigated cells. However, we observed a significantly increased production of tumour necrosis factor-α by CD8 T cells and Granzyme B by natural killer cells and γδ T cells compared to controls. Hyperresponsiveness of cytotoxic blood lymphocytes did not correlate with glycaemia or body mass index, but instead was associated with older age and longer diabetes duration.

Conclusions: Type 2 diabetes is associated with an increased pro-inflammatory potential of cytotoxic blood lymphocytes correlating with age and diabetes duration. Further research is necessary to explore potential benefits of diabetes medications in reverting this effect.