[Correlation between the level of serum IL-6 and the severity of infection in patients with diabetic foot].

To explore the correlation between the level of serum interleukin-6 (IL-6) and the severity of infection in patients with diabetic foot (DF) and the auxiliary value of IL-6 in DF diagnosis, and aim to provide reference for clinical treatment. Based on the hospital medical record system and the laboratory system, a retrospective analysis with case-control study was conducted on the data of patients in Liyuan Hospital affiliated to Tongji Medical College, Huazhong University of Science and Technology from January 2020 to September 2024. A total of 377 patients' information was collected, including 31 cases in control group with 17 males and 14 females from 31 to 91 years old and a median age of 71, 63 cases in NDF group with 43 males and 20 females from 37 to 96 years old, with a median age of 71, and 283 patients in DF group with 197 males and 86 females from 36 to 96 years, with a median age of 67. According to classification of infection severity, paints in the group of diabetes with DF were divided into mild infection subgroup (72 cases), moderate infection subgroup (143 cases) and severe infection subgroup (68 cases). The results showed that there were no statistically significant differences in age and gender among the three groups in the study (=1.795/=2.81, >0.05). The non parametric test results showed that there were statistically significant differences in IL-6, C-reactive protein (CRP), procalcitonin (PCT), white blood cell (WBC) and glucose (GLU) among the three groups of patients (=12.480, 36.277, 12.432, 12.838, 18.334, <0.05). The pairwise comparison results showed that compared with the control group, the NDF group had higher levels of CRP, PCT and GLU (=20.259, 20.118, 20.056, <0.05), and the levels of IL-6, CRP, PCT and WBC(=14.934,14.933,14.829,14.934, <0.05) were higher in the DF group. Both of the differences were statistically significant. But the difference of IL-6, CRP, PCT, WBC and GLU between the NDF and DF group was not statistically significant(=1.202,0.622,0.737,1.036,1.899,). In DF group, there were statistically significant differences in IL-6, CRP, PCT, WBC, and GLU levels among patients in the three infection subgroups (=11.174, 15.136, 8.657, 8.348, 3.698, <0.05).Compared to the mild subgroup, the levels of IL-6, CRP, PCT, WBC and GLU were higher in the severe subgroup were higher(=111.789,237.066,74.683,83.203,15.328, <0.05) and the levels of IL-6, CRP, PCT in the moderate subgroup were higher (=6.877, 8.846, 5.183, <0.05). And both of the differences were statistically significant. But there was no statistically significant difference in WBC and GLU level between the mild and the moderate subgroup(=1.684, 1.039,). The severity of infection in diabetic foot patients was positively correlated with the IL-6 level (=1.033, 95%: 0.024-0.043, <0.05). ROC curve showed that AUC of IL-6 for diagnosis in diabetic foots were 0.635. And joint testing showed that the AUC of IL-6+CRP, IL-6+PCT and IL-6+WBC were 0.718, 0.621, and 0.638 respectively. In conclusion,the level of serum IL-6 may be positively correlated with the severity of infection in diabetic foot patients, which may have auxiliary diagnostic value in predicting diabetic foot infection. And it may provide a reference for the grading of infection severity in diabetic foot patients to gauging serum IL-6 level.