Systemic Immune-Inflammation Index in Diabetic Foot Infections and Osteomyelitis

The systemic immune-inflammation index (SII) was significantly higher in patients with severe infections, those with necrosis, and in those requiring admission, postoperative antibiotics, and any amputation. However, SII was significantly lower in patients with osteomyelitis compared to those with soft tissue infections. The correlation coefficients (rho) between SII and other inflammatory markers were as follows: WBC (Moderate correlation, 0.64, P < .001), ESR (Weak correlation, 0.34, P < .001), and CRP (Moderate correlation, 0.56, P < .001). The correlation coefficient (rho) between SII and the number of days admitted was moderate, 0.42 (P < .001). Based on a previous experience, SII may be an additional marker to diagnose osteomyelitis in the feet of patients with diabetes. Now, we need further research including SII, a low-cost and easy-to-measure index, in well-designed controlled studies to definitively clarify its role.