Short-physical performance battery: complete mediator of cognitive depressive symptoms and diabetes mellitus in hemodialysis patients

Abstract Objective This study aimed to examine the relationship between different dimensions of depressive symptoms and the presence of diabetes mellitus in hemodialysis patients. Additionally, the study sought to elucidate the mediating effect of physical performance on this association. Methods This was a cross-sectional multicenter study conducted between July 2020 and March 2023, involving 1024 patients from eight hemodialysis centers in Shanghai. Diabetes mellitus was based on a documented physician diagnosis and blood glucose tests. Physical performance and depressive symptoms were assessed using short-physical performance battery (SPPB) and the patient health questionnaire-9, respectively. Regression and mediation analysis were applied to statistical analysis. Results Among the 1024 participants, 39.26% (n = 402) were found to have coexisting diabetes mellitus. Diminished SPPB scores (OR = 0.843, 95% CI = 0.792–0.897) and cognitive depressive symptoms (OR = 1.068, 95% CI = 1.011–1.129) exhibited significant associations with diabetes mellitus, while somatic depressive symptoms did not show a significant correlation. Notably, SPPB emerged as a complete mediator in the relationship between cognitive depressive symptoms and diabetes mellitus. The observed indirect effect of SPPB on this relationship was estimated at 0.038 (95% CI: 0.021–0.057). Conclusion This study showed an association between diabetes mellitus and cognitive depressive symptoms in patients undergoing hemodialysis, with physical performance appearing to mediate the relationship between diabetes mellitus and depressive symptoms.