How inflammation underlies physical and organ function in acutely admitted older medical patients

Abstract

Objectives: To investigate whether systemic inflammation in acutely admitted older medical patients (age >65 years) is associated with physical performance and organ dysfunction. Organ dysfunction´s association with physical performance, and whether these associations are mediated by systemic inflammation, was also investigated.

Methods: A cross-sectional study in an Emergency Department. Physical performance was assessed by handgrip strength and de Morton Mobility Index (DEMMI), and organ dysfunction by FI-OutRef, the number of standard blood tests outside the reference range. Systemic inflammation was assessed by suPAR, TNFα, and IL-6. Associations were investigated by regression analyses adjusted for age, sex, cognitive impairment, CRP, and VitalPAC Modified Early Warning Score.

Results: A total of 369 patients were evaluated. In adjusted analyses, suPAR and TNFα was associated with both physical performance measures (p<0.001- p=0.004), and IL-6 with handgrip strength (p=0.007). All inflammation biomarkers were associated with FI-OutRef (p<0.001). FI-OutRef was also associated with physical performance (all p<0.001); suPAR being the inflammatory biomarker with the highest impact when adjusting for inflammation.

Conclusion: Inflammatory biomarkers are potentially feasible for systematic assessment of vulnerability. Moreover, suPAR may be an important mediator between organ dysfunction and physical performance.

Keywords: Accumulated deficiency; Acute care settings; Biology of Aging; Biomarkers; Frailty; Inflammation.