Results

A total of 384 patients with sepsis were enrolled in the study. Among them, 142 (37%) developed sepsis-related organ dysfunction, while 242 (63%) did not. The mean age of the study population was 55.2 ± 16.1 years, and 229 (59.6%) participants were male.

Patients with organ dysfunction were significantly older than those without organ dysfunction (61.8 ± 15.9 vs. 51.3 ± 15.2 years, p < 0.001). Diabetes mellitus, hypertension, and chronic kidney disease were also more common among patients with organ dysfunction (all p < 0.05) (Table 1).

Variable | No organ dysfunction (n = 242) | Organ dysfunction (n = 142) | p-value
Age (years), mean ± SD | 51.3 ± 15.2 | 61.8 ± 15.9 | <0.001
Male gender, n (%) | 137 (56.6) | 92 (64.8) | 0.113
Diabetes mellitus, n (%) | 84 (34.7) | 79 (55.6) | <0.001
Hypertension, n (%) | 102 (42.1) | 79 (55.6) | 0.011
Chronic kidney disease, n (%) | 27 (11.2) | 36 (25.4) | <0.001
Respiratory infection, n (%) | 96 (39.7) | 63 (44.4) | 0.366
Urinary tract infection, n (%) | 77 (31.8) | 35 (24.6) | 0.136
Abdominal infection, n (%) | 46 (19.0) | 31 (21.8) | 0.510
Other infections, n (%) | 23 (9.5) | 13 (9.2) | 0.906

Laboratory findings are summarized in Table 2. Patients with organ dysfunction had significantly higher neutrophil counts, white blood cell counts, NLR values, and serum creatinine levels, while lymphocyte counts were significantly lower (all p < 0.001).

Variable | No organ dysfunction (n = 242) | Organ dysfunction (n = 142) | p-value
Neutrophil count (× 10⁹/L) | 8.8 ± 2.6 | 12.9 ± 3.5 | <0.001
Lymphocyte count (× 10⁹/L) | 1.84 ± 0.63 | 1.07 ± 0.43 | <0.001
NLR | 5.4 ± 2.2 | 12.4 ± 4.6 | <0.001
Serum creatinine (mg/dL) | 1.09 ± 0.34 | 2.11 ± 0.89 | <0.001
White blood cell count (× 10⁹/L) | 12.1 ± 3.8 | 15.8 ± 4.9 | <0.001

ROC curve analysis was performed to assess the predictive ability of NLR and serum creatinine for sepsis-related organ dysfunction. NLR showed good diagnostic performance, with an area under the curve (AUC) of 0.868 (95% CI: 0.831-0.905). At a cutoff value of >8.3, NLR showed 85.2% sensitivity and 79.3% specificity. Serum creatinine also showed good predictive ability, with an AUC of 0.831 (95% CI: 0.790-0.873). At a cutoff value of >1.48 mg/dL, serum creatinine showed 80.3% sensitivity and 75.6% specificity (Table 3). The ROC curve is shown in Figure 1.

Parameter | AUC (95% CI) | Cutoff value | Sensitivity (%) | Specificity (%) | p-value
NLR | 0.868 (0.831-0.905) | >8.3 | 85.2 | 79.3 | <0.001
Serum creatinine | 0.831 (0.790-0.873) | >1.48 mg/dL | 80.3 | 75.6 | <0.001

Figure 1: ROC curve of NLR and serum creatinine for prediction of sepsis-related organ dysfunctionAUC: area under the curve; NLR: neutrophil-to-lymphocyte ratio; ROC: receiver operating characteristic

Multivariable logistic regression analysis showed that increasing age, diabetes mellitus, chronic kidney disease, NLR, and serum creatinine were independently associated with organ dysfunction (Table 4).

Variable | Adjusted OR | 95% CI | p-value
Age (per year increase) | 1.03 | 1.02-1.05 | <0.001
Male gender | 1.16 | 0.74-1.82 | 0.514
Diabetes mellitus | 1.92 | 1.22-3.04 | 0.005
Hypertension | 1.29 | 0.82-2.04 | 0.265
Chronic kidney disease | 2.58 | 1.39-4.79 | 0.003
NLR (per unit increase) | 1.28 | 1.20-1.36 | <0.001
Serum creatinine (per mg/dL increase) | 3.04 | 2.06-4.50 | <0.001