Effects of type 2 diabetes on mortality and immunity responses in sepsis patients: a retrospective cohort study

Aim: ： The study aimed to investigate the association between comorbid Type 2 diabetes mellitus (T2DM) and sepsis outcomes with new evidence and compare the immunity responsesof sepsis patients with T2DMand non-diabetics. Methods: : We conducted a retrospective data collection from consecutive patients diagnosed with sepsis. Utilizing propensity score matching (PSM), we matched T2DM patients with non-diabetics. We subsequently performed a comparative analysis of immune markers and primary clinical outcomes. Additionally, we examined the correlation between HbA1c levels and immunity parameters. Results: : Following the PSM, sepsis patients with comorbid T2DM exhibited a reduced risk of 28-day (odds ratio (OR): 0.62; 95% confidence interval (CI): 0.41-0.94; P=0.031) and 90-day (OR: 0.64; 95% CI: 0.45-0.89; P=0.010) in-hospital mortality. Notably, T2DM patients showed elevated levels of lymphocytes and C4, while their IGM and IGG levels were lower than non-diabetics. Furthermore, a positive correlation was found between C4 (r =0.161, p = 0.016) and HbA1c, whereas IGM (r =-0.194, p = 0.001) and IGG (r =-0.221, p = 0.003) exhibited a negative association with HbA1c. These findings suggest that HbA1c partially influences the plasma IGM and IGG levels. Conclusions: : T2DM is associated with a reduced risk of mortality in sepsis. Patients with T2DM exhibit enhanced levels of lymphocytes and C4 but reduced levels of IGG and IGM compared to non-diabetics. Additionally, IGM and IGG levels in sepsis patients with T2DM are partially influenced by HbA1c levels.