Blood Neutrophil-to-Lymphocyte Ratio and Urine IL-8 Levels Predict the Type of Bacterial Urinary Tract Infection in Type 2 Diabetes Mellitus Patients.

Background: Extended-spectrum ß-lactamase (ESBL)-producing and are the most common uropathogens causing UTI (urinary tract infection) in type 2 diabetes mellitus (T2DM). Circulatory inflammatory markers such as C-reactive protein (CRP) and neutrophil-to-lymphocyte ratio (NLR) are usually dysregulated during UTI. However, the differential regulation of these inflammatory signatures during and UTI in T2DM has not been determined.

Methods: A case-control study on 466 patients was performed to investigate the inflammatory signatures indicative of ESBL- and UTIs in T2DM. Serum CRP levels and blood NLR for these patients were determined and associated with and ESBL uropathogen using multivariate logistic regression analysis. Urinary interleukin 8 (IL-8) levels were also assessed and associated with these two UTI uropathogens in T2DM. The association of the two ESBL-uropathogens with the survival outcomes of T2DM patients was also analyzed using Cox-proportional hazard model.

Results: T2DM patients with ESBL- UTI had lower serum CRP levels (median, CRP mg/dL 33.7 vs 39.8, respectively; P=0.023) and higher blood NLR (median, NLR 3.2 vs 2.6, respectively; P=0.010) compared to those with UTIs (<0.001). Moreover, in T2DM, the urinary IL-8 levels was higher in ESBL- compared to those with UTIs (<0.0001). After adjusting for confounders, including age, gender, serum albumin, hemoglobulin, leukocytes, and platelet counts, T2DM patients with blood NLR ≥ 3.5 were at higher risk for ESBL- UTIs than ESBL- UTIs (odds ratio [OR], 3.61, 95% confidence interval, Cl, 1.49-8.73; P=0.004). Moreover, T2DM patients with ESBL- UTIs had higher all-cause mortality (hazard ratio [HR], 4.09; 95%, 1.14-14.59) than those with UTIs.

Conclusion: Serum CRP levels, blood NLR, and IL-8 urinary levels differentiate ESBL- from UTIs in T2DM.