A prospective cohort study published in Medicine (Baltimore) has identified circulating fatty acid binding protein 4 (FABP 4) as a potential biomarker for early postoperative risk stratification in osteoarthritis patients undergoing major joint arthroplasty. The findings demonstrate a significant association between elevated preoperative FABP4 levels and the development of local complications within 90 days following total knee arthroplasty and total hip arthroplasty.
With the global rise in arthroplasty procedures driven by aging populations and increasing burden of osteoarthritis, early identification of patients at risk for postoperative complications remains a clinical priority. While traditional risk stratification relies on demographic and perioperative variables, there is growing interest in integrating circulating biomarkers that reflect underlying metabolic and inflammatory states.
Fatty acid binding proteins are a family of low molecular weight intracellular proteins, typically 126 to 134 amino acids in length, that bind long-chain fatty acids and regulate lipid transport and signaling. FABP4, predominantly expressed in adipocytes and macrophages, is secreted in response to lipolytic stimuli mediated by cyclic AMP. Beyond its established role in lipid metabolism, FABP4 functions as an adipokine involved in systemic inflammation, insulin resistance, and endothelial dysfunction. Experimental data suggest that FABP4 modulates inflammatory signaling pathways and contributes to oxidative stress and apoptosis, mechanisms that may be relevant in postoperative tissue response and wound healing.
In this study, investigators enrolled 400 patients undergoing primary TKA or THA, along with 100 healthy controls. Patients were prospectively followed and categorized based on the occurrence of local postoperative complications within 90 days, including wound-related issues, infection, and delayed healing. Plasma FABP4 concentrations were quantified using enzyme-linked immunosorbent assay, and associations with clinical variables were analyzed.
Patients who developed postoperative complications exhibited significantly higher circulating FABP4 levels compared with those without complications. On multivariate logistic regression analysis, FABP4 concentration emerged as an independent predictor of 90-day local complications, with an odds ratio of 1.521 (95% CI 1.190 to 1.944, P = 0.001). In addition, the ASA Physical Status Classification and estimated intraoperative blood loss were identified as independent risk factors. The observed association with ASA classification may reflect underlying systemic health status, although the direction of effect in this cohort warrants further investigation.
From a mechanistic perspective, elevated FABP4 levels may indicate a pro-inflammatory and metabolically dysregulated state, which could adversely affect postoperative recovery. Increased inflammatory signaling, impaired microvascular function, and altered lipid metabolism may contribute to compromised wound healing and increased susceptibility to local complications. These findings align with emerging concepts linking metabolic inflammation to surgical outcomes.
The clinical implications of this study are noteworthy. Preoperative assessment of FABP4 could complement existing risk models and enable more refined patient stratification. High-risk individuals may benefit from targeted perioperative optimization strategies, including tighter metabolic control, minimization of surgical blood loss, and enhanced postoperative monitoring. Larger multicenter studies and validation across diverse patient populations will be essential to establish the reproducibility and clinical utility of FABP4 as a predictive biomarker.
In summary, this study positions FABP4 as a promising link between metabolic inflammation and postoperative outcomes in joint arthroplasty. Incorporation of such biomarkers into perioperative care pathways may represent an important step toward more personalized and predictive surgical medicine.
References
- Lin S, Zhang X, Xia X, Xu G, Pan H. Association between elevated circulating FABP4 levels and postoperative prognosis in osteoarthritis patients undergoing joint arthroplasty: A prospective cohort study. Medicine (Baltimore). 2026 Jan 16;105(3):e44697.
- Mao H, Han B, Li H, Tao Y, Wu W. FABP4 knockdown suppresses inflammation, apoptosis and extracellular matrix degradation in IL-1β-induced chondrocytes by activating PPARγ to regulate the NF-κB signaling pathway. Mol Med Rep. 2021 Dec;24(6):855.