Association between preoperative hypoalbuminemia and surgical site infection in abdominal surgery: a systematic review and meta-analysis

Surgical site infections (SSIs) represent a significant postoperative complication following gastrointestinal surgery. Hypoalbuminemia has been proposed as a potential risk factor, but the strength of this association remains unclear. This review aimed to systematically evaluate the relationship between preoperative serum albumin levels and SSI risk in patients undergoing gastrointestinal surgery. A systematic search was conducted in PubMed, Web of Science, and Scopus from inception through November 2025. Studies were eligible if they examined the association between serum albumin and SSI in adult patients undergoing gastrointestinal surgery, measured preoperative serum albumin levels, and reported SSI as an outcome. Two separate analyses were performed: odds ratios (OR) comparing hypoalbuminemia versus normal albumin groups, and standardized mean differences (SMD) comparing albumin levels between patients with and without SSI. Twenty-three studies, involving 681,181 patients, were included. The meta-analysis demonstrated that hypoalbuminemia significantly increased SSI risk (OR 2.37, 95% CI: 1.84–3.05, p < 0.001). Analysis of studies comparing mean albumin levels showed patients with SSI had significantly lower albumin concentrations than those without SSI (SMD − 0.80, 95% CI: -1.21 to -0.39, p < 0.001). Sensitivity analyses confirmed the robustness of findings, and no publication bias was detected. Preoperative hypoalbuminemia is strongly associated with increased SSI risk following gastrointestinal surgery. From a clinical and patient safety perspective, serum albumin should be incorporated into preoperative risk stratification to identify high-risk patients and guide targeted interventions.