Inflammation–Metabolism Score Flags Kidney Injury Risk After Abdominal Surgery

Patients whose blood shows a combined signature of high inflammation and impaired metabolic regulation before elective abdominal surgery face a measurably higher risk of developing acute kidney injury afterward, according to a retrospective cohort study conducted at Weifang People's Hospital in China. The study focused on a composite laboratory measure known as the C-reactive protein–triglyceride glucose index, or CTI, and tracked whether patients developed postoperative acute kidney injury within seven days of surgery. Postoperative acute kidney injury is a common and serious complication following abdominal surgery and is strongly associated with poor prognosis.

The researchers note that traditional diagnostic markers for the condition lack sensitivity, which motivated their search for a preoperative signal that could identify vulnerable patients before they reach the operating table. The CTI was designed as an innovative composite marker for evaluating metabolic-inflammatory dysregulation, comprehensively integrating markers of insulin resistance and systemic inflammation into a single value. By combining this metabolic component with C-reactive protein, a standard marker of systemic inflammation, the CTI aims to capture what the authors describe as a systemic immuno-metabolic phenotype: the joint state of a patient's inflammatory activity and metabolic regulation at the time of surgery.

The single-center retrospective study included adult patients who underwent elective major abdominal surgery between April 2020 and April 2025. The preoperative CTI served as the primary exposure variable, and the primary outcome was the incidence of acute kidney injury within seven days after surgery, defined according to the KDIGO creatinine criteria. In total, 4,658 patients were included, of whom 222, or 4.77 percent, developed postoperative acute kidney injury.

After full adjustment for confounders using multivariable logistic regression, higher CTI values were significantly associated with increased risk of postoperative acute kidney injury, with an odds ratio of 1.28 and a 95 percent confidence interval of 1.09 to 1.52. The contrast between extremes of the distribution was sharper: compared with patients in the lowest CTI quartile, those in the highest quartile had a significantly higher risk, with an odds ratio of 1.86 and a 95 percent confidence interval of 1.12 to 3.11. The dose–response relationship was examined with restricted cubic splines, a flexible regression technique that can reveal whether risk rises smoothly or abruptly across a biomarker's range.

That analysis revealed a linear positive association between CTI and postoperative acute kidney injury, meaning risk climbed steadily rather than crossing a sharp tipping point. Subgroup analyses and sensitivity analyses were conducted to evaluate the robustness of the findings across patient characteristics. Predictive performance was assessed with receiver operating characteristic curve analysis, which compares how well different markers discriminate between patients who do and do not experience the outcome.

The area under the curve for CTI was 0.643, significantly greater than the 0.587 achieved by the TyG index alone, with a P value of 0.0003. This comparison indicates that adding the inflammatory component to the metabolic index improves discrimination, although an area under the curve in this range reflects only moderate predictive accuracy rather than a definitive diagnostic test. Beyond kidney injury itself, the study found that CTI values above approximately 9.5 were associated with prolonged postoperative hospital stay.

The authors conclude that this threshold serves as a clinical decision node, offering superior predictive value for prolonged care trajectories and informing targeted perioperative prehabilitation strategies. The findings position the preoperative CTI as an independent risk factor for postoperative acute kidney injury after abdominal surgery, but the evidence carries important constraints. The study is retrospective and single-center, meaning it relied on existing records from one hospital rather than prospective follow-up, and the reported results describe associations rather than demonstrated causal effects.

Because the final, formatted version of the article had not yet been published at the time of this summary, the detailed adjustment variables, subgroup results, and sensitivity analyses that underpin the conclusions will require scrutiny when the complete paper appears. Whether the 9.5 threshold and the observed risk gradients hold up in prospective, multi-center populations remains the key open question raised by this work.

Subject of Research: Preoperative C-reactive protein–triglyceride glucose index and postoperative acute kidney injury risk after elective abdominal surgery

Article Title: Association between the C-reactive protein–triglyceride glucose index and postoperative acute kidney injury after elective abdominal surgery: a retrospective cohort study

Article References: Zhong, Y. Q., Wang, B., Gu, X., Zhang, R., Yue, F., & Zhao, Y. (2026). Association between the C-reactive protein–triglyceride glucose index and postoperative acute kidney injury after elective abdominal surgery: a retrospective cohort study. Frontiers in Medicine, 13, Article 1933511. https://doi.org/10.3389/fmed.2026.1933511

Image Credits: AI Generated

DOI: 10.3389/fmed.2026.1933511

Keywords: C-reactive protein, triglyceride glucose index, postoperative acute kidney injury, elective abdominal surgery, inflammation, insulin resistance, KDIGO criteria, retrospective cohort study, restricted cubic splines, ROC analysis, perioperative risk, hospital length of stay