The relationship between urinary albumin-to-creatinine ratio and bacterial profiles/inflammatory markers in diabetic foot infections: a retrospective cross-sectional observational study.

BACKGROUND

Diabetic foot disease (including diabetic foot infection, DFI) and diabetic nephropathy (DN) are common diabetic complications. Patients with proteinuric DN are more likely to develop DFI, but data linking proteinuria and DFI are limited. We reviewed Urinary Albumin-to-Creatinine Ratio (UACR), pathogenic bacteria and inflammatory indicators of DFI patients from a northern Chinese tertiary hospital (2020-2023).

METHODS

We analyzed clinical data from 325 DFI patients, grouping them by UACR: normoalbuminuria (UACR < 30 mg/g), microalbuminuria (30 ≤ UACR < 300 mg/g), and macroalbuminuria (UACR ≥ 300 mg/g).

RESULTS

This is a single-center, retrospective cross-sectional observational study conducted at a tertiary hospital in northern China. We analyzed the association between UACR and the characteristics of DFI, and adjusted for potential confounding variables in the regression analysis, including glycemic control status, Wagner classification and peripheral vascular disease. This study included 325 DFI patients (66.8% male; 33.2% female), with average diabetes duration 11.9 ± 7.62 years and DFI duration 2.29 ± 0.35 months. We identified 447 bacterial isolates from secretions (193 Gram-positive, 241 Gram-negative, 13 fungi); 67.69% had single-bacterial infections, 32.31% polymicrobial. Bacteria types differed by UACR: normoalbuminuria group had mostly Gram-positive (55.04%, 50.26% Staphylococcus aureus); microalbuminuria group had more polymicrobial infections (40.71%) and dominant Gram-negative (61.21%); macroalbuminuria group also had more Gram-negative (58.57%). Higher UACR correlated with worse inflammation and metabolism.

CONCLUSION

DFI patients with different UACR levels have distinct pathogenic bacteria. Higher UACR relates to worse inflammation and metabolic issues, suggesting a link between DN and DFI. Stratifying by UACR shows local DFI pathogen distribution, guiding clinicians' initial antibiotic use.