Mediating Effects of Inflammatory Markers on the Relationship Between Malnutrition and Depression in Haemodialysis Patients

Background: In hemodialysis (HD) patients, malnutrition and depression are prevalent issues often influenced by inflammatory markers such as CRP, ferritin and albumin. Extensive research has exhibited the robust connection between malnutrition and depression. However, there is a gap in research within Pakistan concerning how inflammatory markers might mediate this relationship.Objective: To evaluate the mediating role of the inflammatory markers on the relationship between malnutrition and depression in patients undergoing maintenance hemodialysis (MHD).Methods: This cross-sectional study was performed at the Nephrology Department, Mayo Hospital, Lahore from October 15, 2023 to January 15, 2024. The research incorporated patients aged ≥18 years with end-stage renal disease (ESRD) going through MHD for more than 3 months. However, patients with stroke, prior psychiatric illness, corticosteroid medication and non-consent were excluded. Malnutrition was assessed through Subjective Global Assessment-Dialysis Malnutrition Score (SGA-DMS), depression was measured using the Patient Health Questionnaire-9 (PHQ-9). The data analysis involved descriptive statistics, Pearson's correlation while the mediation analysis was performed using the PROCESS macro. Results: The study comprised 145 patients. CRP mediated the relationship between malnutrition and depression significantly (a*b= 0.2609, 95% CI: 0.1170-0.4263, p<0.001). Ferritin represented a marginal mediating effect (a*b= 0.0805, 95% CI: 0.0142-0.1609, p= 0.0524) while albumin showed a negative mediating effect (a*b= 0.1107, 95% CI: - 0.0090-0.2219, p=0.0429).Conclusion: Elevated CRP and ferritin levels enhanced the relationship between malnutrition and depression, implying that higher inflammation worsens depressive symptoms in malnourished patients. In contrast, higher albumin levels were inversely associated with depressive symptoms, indicating a possible protective effect in malnourished patients