Fluid overload and inflammation levels in CKD patients: a systematic review

Background: Fluid overload (FO) is commonly associated with cardiovascular complications, but its role in promoting systemic inflammation, particularly in dialysis patients, has received increasing attention. Inflammation is believed to contribute to the worsening outcomes in fluid-overloaded individuals. This systematic review aims to evaluate the role of fluid overload and inflammation levels in CKD patients. Methods: A systematic review was conducted by searching PubMed, Embase, and Scopus databases to identify studies examining the relationship between fluid overload and pro-inflammatory mediators (TNF-α, CRP, IL-6) in dialysis patients. Studies were screened for relevance, duplicates and reviews were excluded, and data were extracted for analysis. The risk of bias was assessed for each included study. Results: Out of 826 initially identified studies, six studies met the inclusion criteria, comprising a total of 6,085 dialysis patients. All included studies reported on the association between the degree of fluid overload and inflammatory marker levels. Patients with fluid overload consistently showed significantly higher levels of CRP, IL-6, and TNF-α compared to normovolemic controls (p < 0.001). Conclusion: Fluid overload is strongly associated with elevated levels of systemic inflammatory markers in dialysis patients, suggesting a bidirectional relationship between fluid status and inflammation. These findings highlight the need for long-term, randomized studies with larger sample sizes to elucidate this relationship and its clinical implications further.